Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-4584 Wissenschaftlicher Artikel Zhang, Yongzheng Nonlocal dynamic Kirchhoff plate formulation based on nonlocal operator method In this study, we propose a nonlocal operator method (NOM) for the dynamic analysis of (thin) Kirchhoff plates. The nonlocal Hessian operator is derived based on a second-order Taylor series expansion. The NOM does not require any shape functions and associated derivatives as 'classical' approaches such as FEM, drastically facilitating the implementation. Furthermore, NOM is higher order continuous, which is exploited for thin plate analysis that requires C1 continuity. The nonlocal dynamic governing formulation and operator energy functional for Kirchhoff plates are derived from a variational principle. The Verlet-velocity algorithm is used for the time discretization. After confirming the accuracy of the nonlocal Hessian operator, several numerical examples are simulated by the nonlocal dynamic Kirchhoff plate formulation. London Springer 35 Engineering with Computers 2022 1 35 urn:nbn:de:gbv:wim2-20220209-45849 10.1007/s00366-021-01587-1 Institut für Strukturmechanik (ISM) OPUS4-4476 Wissenschaftlicher Artikel Legatiuk, Dmitrii; Weisz-Patrault, Daniel Coupling of Complex Function Theory and Finite Element Method for Crack Propagation Through Energetic Formulation: Conformal Mapping Approach and Reduction to a Riemann-Hilbert Problem In this paper we present a theoretical background for a coupled analytical-numerical approach to model a crack propagation process in two-dimensional bounded domains. The goal of the coupled analytical-numerical approach is to obtain the correct solution behaviour near the crack tip by help of the analytical solution constructed by using tools of complex function theory and couple it continuously with the finite element solution in the region far from the singularity. In this way, crack propagation could be modelled without using remeshing. Possible directions of crack growth can be calculated through the minimization of the total energy composed of the potential energy and the dissipated energy based on the energy release rate. Within this setting, an analytical solution of a mixed boundary value problem based on complex analysis and conformal mapping techniques is presented in a circular region containing an arbitrary crack path. More precisely, the linear elastic problem is transformed into a Riemann-Hilbert problem in the unit disk for holomorphic functions. Utilising advantages of the analytical solution in the region near the crack tip, the total energy could be evaluated within short computation times for various crack kink angles and lengths leading to a potentially efficient way of computing the minimization procedure. To this end, the paper presents a general strategy of the new coupled approach for crack propagation modelling. Additionally, we also discuss obstacles in the way of practical realisation of this strategy. Heidelberg Springer 23 Computational Methods and Function Theory 2021 1 23 urn:nbn:de:gbv:wim2-20210805-44763 10.1007/s40315-021-00403-7 Professur Angewandte Mathematik OPUS4-4061 Wissenschaftlicher Artikel Gürlebeck, Klaus; Legatiuk, Dmitrii; Nilsson, Henrik; Smarsly, Kay Conceptual modelling: Towards detecting modelling errors in engineering applications Rapid advancements of modern technologies put high demands on mathematical modelling of engineering systems. Typically, systems are no longer "simple" objects, but rather coupled systems involving multiphysics phenomena, the modelling of which involves coupling of models that describe different phenomena. After constructing a mathematical model, it is essential to analyse the correctness of the coupled models and to detect modelling errors compromising the final modelling result. Broadly, there are two classes of modelling errors: (a) errors related to abstract modelling, eg, conceptual errors concerning the coherence of a model as a whole and (b) errors related to concrete modelling or instance modelling, eg, questions of approximation quality and implementation. Instance modelling errors, on the one hand, are relatively well understood. Abstract modelling errors, on the other, are not appropriately addressed by modern modelling methodologies. The aim of this paper is to initiate a discussion on abstract approaches and their usability for mathematical modelling of engineering systems with the goal of making it possible to catch conceptual modelling errors early and automatically by computer assistant tools. To that end, we argue that it is necessary to identify and employ suitable mathematical abstractions to capture an accurate conceptual description of the process of modelling engineering systems. 9 Mathematical Methods in Applied Sciences 1 10 urn:nbn:de:gbv:wim2-20200110-40614 10.1002/mma.5934 Professur Angewandte Mathematik OPUS4-3566 Wissenschaftlicher Artikel Zhang, Chao; Nanthakumar, S.S.; Lahmer, Tom; Rabczuk, Timon Multiple cracks identification for piezoelectric structures Multiple cracks identification for piezoelectric structures 18 International Journal of Fracture 1 19 Institut für Strukturmechanik (ISM) OPUS4-3565 Wissenschaftlicher Artikel Nguyen-Tuan, Long; Könke, Carsten; Bettzieche, Volker; Lahmer, Tom Numerical modeling and validation for 3D coupled-nonlinear thermo-hydro-mechanical problems in masonry dams Numerical modeling and validation for 3D coupled-nonlinear thermo-hydro-mechanical problems in masonry dams 11 Computers & Structures 143 154 Institut für Strukturmechanik (ISM) OPUS4-3562 Wissenschaftlicher Artikel Achenbach, Marcus; Lahmer, Tom; Morgenthal, Guido Global Sensitivity Analysis of Reinforced Concrete Walls Subjected to Standard Fire - A Comparison of Methods Global Sensitivity Analysis of Reinforced Concrete Walls Subjected to Standard Fire—A Comparison of Methods 9 14th International Probabilistic Workshop 97 106 Institut für Strukturmechanik (ISM) OPUS4-3564 Wissenschaftlicher Artikel Göbel, Luise; Lahmer, Tom; Osburg, Andrea Uncertainty analysis in multiscale modeling of concrete based on continuum micromechanics Uncertainty analysis in multiscale modeling of concrete based on continuum micromechanics European Journal of Mechanics-A/Solids Institut für Strukturmechanik (ISM) OPUS4-3596 Wissenschaftlicher Artikel Alalade, Muyiwa; Nguyen-Tuan, Long; Wuttke, Frank; Lahmer, Tom Damage identification in gravity dams using dynamic coupled hydro-mechanical XFEM Damage identification in gravity dams using dynamic coupled hydro-mechanical XFEM. 18 International Journal of Mechanics and Materials in Design 1 19 10.25643/bauhaus-universitaet.3596 Professur Stochastik und Optimierung OPUS4-3579 Wissenschaftlicher Artikel Zhang, Chao; Wang, Cuixia; Lahmer, Tom; He, Pengfei; Rabczuk, Timon A dynamic XFEM formulation for crack identification A dynamic XFEM formulation for crack identification 21 International Journal of Mechanics and Materials in Design 427 448 Institut für Strukturmechanik (ISM) OPUS4-3577 Wissenschaftlicher Artikel Nguyen-Tuan, Long; Lahmer, Tom; Datcheva, Maria; Stoimenova, Eugenia; Schanz, Tom A novel parameter identification approach for buffer elements involving complex coupled thermo-hydro-mechanical analyses A novel parameter identification approach for buffer elements involving complex coupled thermo-hydro-mechanical analyses 9 Computers and Geotechnics 23 32 Institut für Strukturmechanik (ISM) OPUS4-3578 Wissenschaftlicher Artikel Vu-Bac, N.; Lahmer, Tom; Zhuang, Xiaoying; Nguyen-Thoi, T.; Rabczuk, Timon A software framework for probabilistic sensitivity analysis for computationally expensive models A software framework for probabilistic sensitivity analysis for computationally expensive models 12 Advances in Engineering Software 19 31 Institut für Strukturmechanik (ISM) OPUS4-3575 Wissenschaftlicher Artikel Nanthakumar, S.S.; Lahmer, Tom; Zhuang, Xiaoying; Park, Harold S.; Rabczuk, Timon Topology optimization of piezoelectric nanostructures Topology optimization of piezoelectric nanostructures 19 Journal of the Mechanics and Physics of Solids 316 335 Institut für Strukturmechanik (ISM) OPUS4-3568 Wissenschaftlicher Artikel Ghorashi, Seyed Shahram; Lahmer, Tom; Bagherzadeh, Amir Saboor; Zi, Goangseup; Rabczuk, Timon A stochastic computational method based on goal-oriented error estimation for heterogeneous geological materials A stochastic computational method based on goal-oriented error estimation for heterogeneous geological materials Engineering Geology Institut für Strukturmechanik (ISM) OPUS4-3574 Wissenschaftlicher Artikel Nanthakumar, S.S.; Lahmer, Tom; Zhuang, Xiaoying; Zi, Goangseup; Rabczuk, Timon Detection of material interfaces using a regularized level set method in piezoelectric structures Detection of material interfaces using a regularized level set method in piezoelectric structures 23 Inverse Problems in Science and Engineering 153 176 Institut für Strukturmechanik (ISM) OPUS4-3569 Wissenschaftlicher Artikel Lahmer, Tom; Bock, Sebastian; Hildebrand, Jörg; Gürlebeck, Klaus Non-destructive identification of residual stresses in steel under thermal loadings Non-destructive identification of residual stresses in steel under thermal loadings 16 Inverse Problems in Science and Engineering 1 17 Institut für Strukturmechanik (ISM) OPUS4-3576 Wissenschaftlicher Artikel Nguyen-Tuan, Long; Lahmer, Tom; Datcheva, Maria; Schanz, Tom Global and local sensitivity analyses for coupled thermo-hydro-mechanical problems Global and local sensitivity analyses for coupled thermo-hydro-mechanical problems International Journal for Numerical and Analytical Methods in Geomechanics Institut für Strukturmechanik (ISM) OPUS4-3572 Wissenschaftlicher Artikel Marzban, Samira; Lahmer, Tom Conceptual implementation of the variance-based sensitivity analysis for the calculation of the first-order effects Conceptual implementation of the variance-based sensitivity analysis for the calculation of the first-order effects 22 Journal of Statistical Theory and Practice 589 611 Institut für Strukturmechanik (ISM) OPUS4-3573 Wissenschaftlicher Artikel Nanthakumar, S.S.; Lahmer, Tom; Rabczuk, Timon Detection of multiple flaws in piezoelectric structures using XFEM and level sets Detection of multiple flaws in piezoelectric structures using XFEM and level sets International Journal for Numerical Methods in Engineering 960 Institut für Strukturmechanik (ISM) OPUS4-3570 Wissenschaftlicher Artikel Lahmer, Tom; Nguyen-Tuan, Long; Könke, Carsten; Bettzieche, Volker Thermo-hydro-mechanische 3-D-Simulation von Staumauern-Modellierung und Validierung Thermo-hydro-mechanische 3-D-Simulation von Staumauern-Modellierung und Validierung 3 WASSERWIRTSCHAFT 27 30 Institut für Strukturmechanik (ISM) OPUS4-2802 Konferenzveröffentlichung Ignatova, Elena; Kirschke, Heiko; Tauscher, Eike; Smarsly, Kay Gürlebeck, Klaus; Lahmer, Tom PARAMETRIC GEOMETRIC MODELING IN CONSTRUCTION PLANNING USING INDUSTRY FOUNDATION CLASSES One of the most promising and recent advances in computer-based planning is the transition from classical geometric modeling to building information modeling (BIM). Building information models support the representation, storage, and exchange of various information relevant to construction planning. This information can be used for describing, e.g., geometric/physical properties or costs of a building, for creating construction schedules, or for representing other characteristics of construction projects. Based on this information, plans and specifications as well as reports and presentations of a planned building can be created automatically. A fundamental principle of BIM is object parameterization, which allows specifying geometrical, numerical, algebraic and associative dependencies between objects contained in a building information model. In this paper, existing challenges of parametric modeling using the Industry Foundation Classes (IFC) as a federated model for integrated planning are shown, and open research questions are discussed. 8 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28024 10.25643/bauhaus-universitaet.2802 Professur Informatik im Bauwesen OPUS4-2823 Konferenzveröffentlichung Smarsly, Kay; Tauscher, Eike Gürlebeck, Klaus; Lahmer, Tom IFC-BASED MONITORING INFORMATION MODELING FOR DATA MANAGEMENT IN STRUCTURAL HEALTH MONITORING This conceptual paper discusses opportunities and challenges towards the digital representation of structural health monitoring systems using the Industry Foundation Classes (IFC) standard. State-of-the-art sensor nodes, collecting structural and environmental data from civil infrastructure systems, are capable of processing and analyzing the data sets directly on-board the nodes. Structural health monitoring (SHM) based on sensor nodes that possess so called "on-chip intelligence" is, in this study, referred to as "intelligent SHM", and the infrastructure system being equipped with an intelligent SHM system is referred to as "intelligent infrastructure". Although intelligent SHM will continue to grow, it is not possible, on a well-defined formalism, to digitally represent information about sensors, about the overall SHM system, and about the monitoring strategies being implemented ("monitoring-related information"). Based on a review of available SHM regulations and guidelines as well as existing sensor models and sensor modeling languages, this conceptual paper investigates how to digitally represent monitoring-related information in a semantic model. With the Industry Foundation Classes, there exists an open standard for the digital representation of building information; however, it is not possible to represent monitoring-related information using the IFC object model. This paper proposes a conceptual approach for extending the current IFC object model in order to include monitoring-related information. Taking civil infrastructure systems as an illustrative example, it becomes possible to adequately represent, process, and exchange monitoring-related information throughout the whole life cycle of civil infrastructure systems, which is referred to as monitoring information modeling (MIM). However, since this paper is conceptual, additional research efforts are required to further investigate, implement, and validate the proposed concepts and methods. 7 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28237 10.25643/bauhaus-universitaet.2823 Professur Informatik im Bauwesen OPUS4-2800 Konferenzveröffentlichung Hölter, Raoul; Mahmoudi, Elham; Schanz, Tom Gürlebeck, Klaus; Lahmer, Tom OPTIMAL SENSOR LOCATION FOR PARAMETER IDENTIFICATION IN SOFT CLAY Performing parameter identification prior to numerical simulation is an essential task in geotechnical engineering. However, it has to be kept in mind that the accuracy of the obtained parameter is closely related to the chosen experimental setup, such as the number of sensors as well as their location. A well considered position of sensors can increase the quality of the measurement and to reduce the number of monitoring points. This Paper illustrates this concept by means of a loading device that is used to identify the stiffness and permeability of soft clays. With an initial setup of the measurement devices the pore water pressure and the vertical displacements are recorded and used to identify the afore mentioned parameters. Starting from these identified parameters, the optimal measurement setup is investigated with a method based on global sensitivity analysis. This method shows an optimal sensor location assuming three sensors for each measured quantity, and the results are discussed. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28008 10.25643/bauhaus-universitaet.2800 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2798 Konferenzveröffentlichung Grigor'ev, Yuri Gürlebeck, Klaus; Lahmer, Tom REGULAR QUATERNIONIC FUNCTIONS AND THEIR APPLICATIONS The theory of regular quaternionic functions of a reduced quaternionic variable is a 3-dimensional generalization of complex analysis. The Moisil-Theodorescu system (MTS) is a regularity condition for such functions depending on the radius vector r = ix+jy+kz seen as a reduced quaternionic variable. The analogues of the main theorems of complex analysis for the MTS in quaternion forms are established: Cauchy, Cauchy integral formula, Taylor and Laurent series, approximation theorems and Cauchy type integral properties. The analogues of positive powers (inner spherical monogenics) are investigated: the set of recurrence formulas between the inner spherical monogenics and the explicit formulas are established. Some applications of the regular function in the elasticity theory and hydrodynamics are given. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27988 10.25643/bauhaus-universitaet.2798 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2795 Konferenzveröffentlichung Volkov, Andrey; Kirschke, Heiko; Chelyshkov, Pavel; Sedov, Artem; Lysenko, Denis Gürlebeck, Klaus; Lahmer, Tom THE CRITERIA'S SET WITH INVARIANT DESIGN BUILDING ELEMENTS ON THE BASE OF THREE IMPUTATIONS: "CONVENIENCE", "SAFETY" AND "ENERGY-EFFICIENCY" The paper deals with the formalization of the criteria for constructing building management systems. We consider three criteria - "convenience", "safety" and "energyefficiency". For each objective proposed method of calculation. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27956 10.25643/bauhaus-universitaet.2795 Professur Angewandte Mathematik OPUS4-2812 Konferenzveröffentlichung Macedo, Joaquim Miguel; Benta, Agostinho; Picado-Santos, Luis Gürlebeck, Klaus; Lahmer, Tom USE OF MICROSIMULATION IN THE ADAPTATION TO PORTUGAL OF THE HCM 2000 METHODOLOGY FOR BASIC FREEWAY SEGMENTS Portugal is one of the European countries with higher spatial and population freeway network coverage. The sharp growth of this network in the last years instigates the use of methods of analysis and the evaluation of their quality of service in terms of the traffic performance, typically performed through internationally accepted methodologies, namely that presented in the Highway Capacity Manual (HCM). Lately, the use of microscopic traffic simulation models has been increasingly widespread. These models simulate the individual movement of the vehicles, allowing to perform traffic analysis. The main target of this study was to verify the possibility of using microsimulation as an auxiliary tool in the adaptation of the methodology by HCM 2000 to Portugal. For this purpose, were used the microscopic simulators AIMSUN and VISSIM for the simulation of the traffic circulation in the A5 Portuguese freeway. The results allowed the analysis of the influence of the main geometric and traffic factors involved in the methodology by HCM 2000. In conclusion, the study presents the main advantages and limitations of the microsimulators AIMSUN and VISSIM in modelling the traffic circulation in Portuguese freeways. The main limitation is that these microsimulators are not able to simulate explicitly some of the factors considered in the HCM 2000 methodology, which invalidates their direct use as a tool in the quantification of those effects and, consequently, makes the direct adaptation of this methodology to Portugal impracticable. 7 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28122 10.25643/bauhaus-universitaet.2812 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2803 Konferenzveröffentlichung Jahr, Katrin; Schlich, Robert; Dragos, Kosmas; Smarsly, Kay Gürlebeck, Klaus; Lahmer, Tom DECENTRALIZED AUTONOMOUS FAULT DETECTION IN WIRELESS STRUCTURAL HEALTH MONITORING SYSTEMS USING STRUCTURAL RESPONSE DATA Sensor faults can affect the dependability and the accuracy of structural health monitoring (SHM) systems. Recent studies demonstrate that artificial neural networks can be used to detect sensor faults. In this paper, decentralized artificial neural networks (ANNs) are applied for autonomous sensor fault detection. On each sensor node of a wireless SHM system, an ANN is implemented to measure and to process structural response data. Structural response data is predicted by each sensor node based on correlations between adjacent sensor nodes and on redundancies inherent in the SHM system. Evaluating the deviations (or residuals) between measured and predicted data, sensor faults are autonomously detected by the wireless sensor nodes in a fully decentralized manner. A prototype SHM system implemented in this study, which is capable of decentralized autonomous sensor fault detection, is validated in laboratory experiments through simulated sensor faults. Several topologies and modes of operation of the embedded ANNs are investigated with respect to the dependability and the accuracy of the fault detection approach. In conclusion, the prototype SHM system is able to accurately detect sensor faults, demonstrating that neural networks, processing decentralized structural response data, facilitate autonomous fault detection, thus increasing the dependability and the accuracy of structural health monitoring systems. 8 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28031 10.25643/bauhaus-universitaet.2803 Professur Angewandte Mathematik OPUS4-2813 Konferenzveröffentlichung Meier, Jörg; Schanz, Tom Gürlebeck, Klaus; Lahmer, Tom Benchmarking of Optimization Algorithms In this paper, we present an empirical approach for objective and quantitative benchmarking of optimization algorithms with respect to characteristics induced by the forward calculation. Due to the professional background of the authors, this benchmarking strategy is illustrated on a selection of search methods in regard to expected characteristics of geotechnical parameter back calculation problems. Starting from brief introduction into the approach employed, a strategy for optimization algorithm benchmarking is introduced. The benchmarking utilizes statistical tests carried out on well-known test functions superposed with perturbations, both chosen to mimic objective function topologies found for geotechnical objective function topologies. Here, the moved axis parallel hyper-ellipsoid test function and the generalized Ackley test function in conjunction with an adjustable quantity of objective function topology roughness and fraction of failing forward calculations is analyzed. In total, results for 5 optimization algorithms are presented, compared and discussed. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28134 10.25643/bauhaus-universitaet.2813 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2809 Konferenzveröffentlichung Khristich, Dmitrii; Astapov, Yuri Gürlebeck, Klaus; Lahmer, Tom VARIATIONAL POSITING AND SOLUTION OF COUPLED THERMOMECHANICAL PROBLEMS IN A REFERENCE CONFIGURATION Variational formulation of a coupled thermomechanical problem of anisotropic solids for the case of non-isothermal finite deformations in a reference configuration is shown. The formulation of the problem includes: a condition of equilibrium flow of a deformation process in the reference configuration; an equation of a coupled heat conductivity in a variational form, in which an influence of deformation characteristics of a process on the temperature field is taken into account; tensor-linear constitutive relations for a hypoelastic material; kinematic and evolutional relations; initial and boundary conditions. Based on this formulation several axisymmetric isothermal and coupled problems of finite deformations of isotropic and anisotropic bodies are solved. The solution of coupled thermomechanical problems for a hollow cylinder in case of finite deformation showed an essential influence of coupling on distribution of temperature, stresses and strains. The obtained solutions show the development of stressstrain state and temperature changing in axisymmetric bodies in the case of finite deformations. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28091 10.25643/bauhaus-universitaet.2809 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2797 Konferenzveröffentlichung Göbel, Luise; Osburg, Andrea; Lahmer, Tom Gürlebeck, Klaus; Lahmer, Tom STUDY OF ANALYTICAL MODELS OF THE MECHANICAL BEHAVIOR OF POLYMER-MODIFIED CONCRETE Polymer modification of mortar and concrete is a widely used technique in order to improve their durability properties. Hitherto, the main application fields of such materials are repair and restoration of buildings. However, due to the constant increment of service life requirements and the cost efficiency, polymer modified concrete (PCC) is also used for construction purposes. Therefore, there is a demand for studying the mechanical properties of PCC and entitative differences compared to conventional concrete (CC). It is significant to investigate whether all the assumed hypotheses and existing analytical formulations about CC are also valid for PCC. In the present study, analytical models available in the literature are evaluated. These models are used for estimating mechanical properties of concrete. The investigated property in this study is the modulus of elasticity, which is estimated with respect to the value of compressive strength. One existing database was extended and adapted for polymer-modified concrete mixtures along with their experimentally measured mechanical properties. Based on the indexed data a comparison between model predictions and experiments was conducted by calculation of forecast errors. 9 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27973 10.25643/bauhaus-universitaet.2797 Graduiertenkolleg 1462 OPUS4-2825 Konferenzveröffentlichung Vieira, Nelson Gürlebeck, Klaus; Lahmer, Tom SOME RESULTS IN FRACTIONAL CLIFFORD ANALYSIS What is nowadays called (classic) Clifford analysis consists in the establishment of a function theory for functions belonging to the kernel of the Dirac operator. While such functions can very well describe problems of a particle with internal SU(2)-symmetries, higher order symmetries are beyond this theory. Although many modifications (such as Yang-Mills theory) were suggested over the years they could not address the principal problem, the need of a n-fold factorization of the d'Alembert operator. In this paper we present the basic tools of a fractional function theory in higher dimensions, for the transport operator (alpha = 1/2 ), by means of a fractional correspondence to the Weyl relations via fractional Riemann-Liouville derivatives. A Fischer decomposition, fractional Euler and Gamma operators, monogenic projection, and basic fractional homogeneous powers are constructed. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28256 10.25643/bauhaus-universitaet.2825 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2796 Konferenzveröffentlichung Ferreira, Milton dos Santos; Vieira, Nelson Gürlebeck, Klaus; Lahmer, Tom EIGENFUNCTIONS AND FUNDAMENTAL SOLUTIONS FOR THE FRACTIONAL LAPLACIAN IN 3 DIMENSIONS Recently there has been a surge of interest in PDEs involving fractional derivatives in different fields of engineering. In this extended abstract we present some of the results developedin [3]. We compute the fundamental solution for the three-parameter fractional Laplace operator Δ by transforming the eigenfunction equation into an integral equation and applying the method of separation of variables. The obtained solutions are expressed in terms of Mittag-Leffer functions. For more details we refer the interested reader to [3] where it is also presented an operational approach based on the two Laplace transform. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27968 10.25643/bauhaus-universitaet.2796 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2814 Konferenzveröffentlichung Musial, Michal Gürlebeck, Klaus; Lahmer, Tom THE INFLUENCE OF CRACKS AND OVERESTIMATION ERRORS ON THE DEFLECTION OF THE REINFORCED CONCRETE BEAMS IN THE RIGID FINITE ELEMENT METHOD This article presents the Rigid Finite Element Method in the calculation of reinforced concrete beam deflection with cracks. Initially, this method was used in the shipbuilding industry. Later, it was adapted in the homogeneous calculations of the bar structures. In this method, rigid mass discs serve as an element model. In the flat layout, three generalized coordinates (two translational and one rotational) correspond to each disc. These discs are connected by elastic ties. The genuine idea is to take into account a discrete crack in the Rigid Finite Element Method. It consists in the suitable reduction of the rigidity in rotational ties located in the spots, where cracks occurred. The susceptibility of this tie results from the flexural deformability of the element and the occurrence of the crack. As part of the numerical analyses, the influence of cracks on the total deflection of beams was determined. Furthermore, the results of the calculations were compared to the results of the experiment. Overestimations of the calculated deflections against the measured deflections were found. The article specifies the size of the overestimation and describes its causes. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28142 10.25643/bauhaus-universitaet.2814 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2820 Konferenzveröffentlichung Stokmaier, Markus; Class, A.G.; Schulenberg, T.; Lahey Jr., R.T Gürlebeck, Klaus; Lahmer, Tom OPTIMISING ACOUSTIC RESONATORS FOR SONOFUSION EXPERIMENTS WITH EVOLUTIONARY ALGORITHMS The sizing of simple resonators like guitar strings or laser mirrors is directly connected to the wavelength and represents no complex optimisation problem. This is not the case with liquid-filled acoustic resonators of non-trivial geometries, where several masses and stiffnesses of the structure and the fluid have to fit together. This creates a scenario of many competing and interacting resonances varying in relative strength and frequency when design parameters change. Hence, the resonator design involves a parameter-tuning problem with many local optima. As its solution evolutionary algorithms (EA) coupled to a forced-harmonic FE simulation are presented. A new hybrid EA is proposed and compared to two state-of-theart EAs based on selected test problems. The motivating background is the search for better resonators suitable for sonofusion experiments where extreme states of matter are sought in collapsing cavitation bubbles. 8 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28202 10.25643/bauhaus-universitaet.2820 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2792 Konferenzveröffentlichung Al-Yasiri, Zainab; Gürlebeck, Klaus Gürlebeck, Klaus; Lahmer, Tom ON BOUNDARY VALUE PROBLEMS FOR P-LAPLACE AND P-DIRAC EQUATIONS The p-Laplace equation is a nonlinear generalization of the Laplace equation. This generalization is often used as a model problem for special types of nonlinearities. The p-Laplace equation can be seen as a bridge between very general nonlinear equations and the linear Laplace equation. The aim of this paper is to solve the p-Laplace equation for 2 < p < 3 and to find strong solutions. The idea is to apply a hypercomplex integral operator and spatial function theoretic methods to transform the p-Laplace equation into the p-Dirac equation. This equation will be solved iteratively by using a fixed point theorem. 8 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27928 10.25643/bauhaus-universitaet.2792 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2794 Konferenzveröffentlichung Almamou, Abd Albasset; Gebhardt, Thomas; Bock, Sebastian; Hildebrand, Jörg; Schwarz, Willfried Gürlebeck, Klaus; Lahmer, Tom QUALITY CONTROL OF CONSTRUCTED MODELS USING 3D POINT CLOUD Over the last decade, the technology of constructing buildings has been dramatically developed especially with the huge growth of CAD tools that help in modeling buildings, bridges, roads and other construction objects. Often quality control and size accuracy in the factory or on construction site are based on manual measurements of discrete points. These measured points of the realized object or a part of it will be compared with the points of the corresponding CAD model to see whether and where the construction element fits into the respective CAD model. This process is very complicated and difficult even when using modern measuring technology. This is due to the complicated shape of the components, the large amount of manually detected measured data and the high cost of manual processing of measured values. However, by using a modern 3D scanner one gets information of the whole constructed object and one can make a complete comparison against the CAD model. It gives an idea about quality of objects on the whole. In this paper, we present a case study of controlling the quality of measurement during the constructing phase of a steel bridge by using 3D point cloud technology. Preliminary results show that an early detection of mismatching between real element and CAD model could save a lot of time, efforts and obviously expenses. 9 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27944 10.25643/bauhaus-universitaet.2794 Professur Angewandte Mathematik OPUS4-2824 Konferenzveröffentlichung Vasileva, Iuliia Gürlebeck, Klaus; Lahmer, Tom THE PROBLEM OF PARTIAL REINFORCING AN INTERFACE CRACK EDGE BY A RIGID PATCH PLATE UNDER IN-PLANE AND ANTIPLANE LOADS The stress state of a piecewise-homogeneous elastic body, which has a semi-infinite crack along the interface, under in-plane and antiplane loads is considered. One of the crack edges is reinforced by a rigid patch plate on a finite interval adjacent to the crack tip. The crack edges are loaded with specified stresses. The body is stretched at infinity by specified stresses. External forces with a given principal vector and moment act on the patch plate. The problem reduces to a Riemann-Hilbert boundary-value matrix problem with a piecewise-constant coefficient for two complex potentials in the plane case and for one in the antiplane case. The complex potentials are found explicitly using a Gaussian hypergeometric function. The stress state of the body close to the ends of the patch plate, one of which is also simultaneously the crack tip, is investigated. Stress intensity factors near the singular points are determined. 5 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28242 10.25643/bauhaus-universitaet.2824 Professur Angewandte Mathematik OPUS4-2811 Konferenzveröffentlichung Lopes, Nuno; Rodrigues, Daniela; Vila Real, Paulo Gürlebeck, Klaus; Lahmer, Tom ANALYSIS OF STEEL STRUCTURAL MEMBERS IN FIRE WITH SLENDER CROSS-SECTIONS THROUGH BEAM FINITE ELEMENTS APPLYING AN EFFECTIVE CONSTITUTIVE LAW Steel profiles with slender cross-sections are characterized by their high susceptibility to instability phenomena, especially local buckling, which are intensified under fire conditions. This work presents a study on numerical modelling of the behaviour of steel structural elements in case of fire with slender cross-sections. To accurately carry out these analyses it is necessary to take into account those local instability modes, which normally is only possible with shell finite elements. However, aiming at the development of more expeditious methods, particularly important for analysing complete structures in case of fire, recent studies have proposed the use of beam finite elements considering the presence of local buckling through the implementation of a new effective steel constitutive law. The objective of this work is to develop a study to validate this methodology using the program SAFIR. Comparisons are made between the results obtained applying the referred new methodology and finite element analyses using shell elements. The studies were made to laterally restrained beams, unrestrained beams, axially compressed columns and columns subjected to bending plus compression. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28116 10.25643/bauhaus-universitaet.2811 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2817 Konferenzveröffentlichung Rodehorst, Volker Gürlebeck, Klaus; Lahmer, Tom EVALUATION OF THE METRIC TRIFOCAL TENSOR FOR RELATIVE THREE-VIEW ORIENTATION In photogrammetry and computer vision the trifocal tensor is used to describe the geometric relation between projections of points in three views. In this paper we analyze the stability and accuracy of the metric trifocal tensor for calibrated cameras. Since a minimal parameterization of the metric trifocal tensor is challenging, the additional constraints of the interior orientation are applied to the well-known projective 6-point and 7-point algorithms for three images. The experimental results show that the linear 7-point algorithm fails for some noise-free degenerated cases, whereas the minimal 6-point algorithm seems to be competitive even with realistic noise. 7 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28178 10.25643/bauhaus-universitaet.2817 Professur Computer Vision in Engineering OPUS4-2818 Konferenzveröffentlichung Rodrigues, M. Manuela Gürlebeck, Klaus; Lahmer, Tom OPERATIONAL PROPERTIES OF THE LAGUERRE TRANSFORM The Laguerre polynomials appear naturally in many branches of pure and applied mathematics and mathematical physics. Debnath introduced the Laguerre transform and derived some of its properties. He also discussed the applications in study of heat conduction and to the oscillations of a very long and heavy chain with variable tension. An explicit boundedness for some class of Laguerre integral transforms will be present. 5 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28186 10.25643/bauhaus-universitaet.2818 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2805 Konferenzveröffentlichung Karaki, Ghada Gürlebeck, Klaus; Lahmer, Tom SELECTION AND SCALING OF GROUND MOTION RECORDS FOR SEISMIC ANALYSIS USING AN OPTIMIZATION ALGORITHM The nonlinear time history analysis and seismic performance based methods require a set of scaled ground motions. The conventional procedure of ground motion selection is based on matching the motion properties, e.g. magnitude, amplitude, fault distance, and fault mechanism. The seismic target spectrum is only used in the scaling process following the random selection process. Therefore, the aim of the paper is to present a procedure to select a sets of ground motions from a built database of ground motions. The selection procedure is based on running an optimization problem using Dijkstra's algorithm to match the selected set of ground motions to a target response spectrum. The selection and scaling procedure of optimized sets of ground motions is presented by examining the analyses of nonlinear single degree of freedom systems. 7 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28058 10.25643/bauhaus-universitaet.2805 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2826 Konferenzveröffentlichung Wiggenbrock, Jens; Smarsly, Kay Gürlebeck, Klaus; Lahmer, Tom A GENERIC FRAMEWORK SUPPORTING DISTRIBUTED COMPUTING IN ENGINEERING APPLICATIONS Modern distributed engineering applications are based on complex systems consisting of various subsystems that are connected through the Internet. Communication and collaboration within an entire system requires reliable and efficient data exchange between the subsystems. Middleware developed within the web evolution during the past years provides reliable and efficient data exchange for web applications, which can be adopted for solving the data exchange problems in distributed engineering applications. This paper presents a generic approach for reliable and efficient data exchange between engineering devices using existing middleware known from web applications. Different existing middleware is examined with respect to the suitability in engineering applications. In this paper, a suitable middleware is shown and a prototype implementation simulating distributed wind farm control is presented and validated using several performance measurements. 9 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28260 10.25643/bauhaus-universitaet.2826 Professur Angewandte Mathematik OPUS4-3580 Wissenschaftlicher Artikel Lahmer, Tom; Ilg, J.; Lerch, Reinhard Variance-based sensitivity analyses of piezoelectric models Variance-based sensitivity analyses of piezoelectric models 21 Computer Modeling in Engineering & Sciences 105 126 Institut für Strukturmechanik (ISM) OPUS4-2816 Konferenzveröffentlichung Nguyen-Tuan, Long; Lahmer, Tom; Datcheva, Maria; Stoimenova, Eugenia; Schanz, Tom Gürlebeck, Klaus; Lahmer, Tom PARAMETER IDENTIFICATION APPLYING IN COMPLEX THERMO-HYDRO-MECHANICAL PROBLEMS LIKE THE DESIGN OF BUFFER ELEMENTS This study contributes to the identification of coupled THM constitutive model parameters via back analysis against information-rich experiments. A sampling based back analysis approach is proposed comprising both the model parameter identification and the assessment of the reliability of identified model parameters. The results obtained in the context of buffer elements indicate that sensitive parameter estimates generally obey the normal distribution. According to the sensitivity of the parameters and the probability distribution of the samples we can provide confidence intervals for the estimated parameters and thus allow a qualitative estimation on the identified parameters which are in future work used as inputs for prognosis computations of buffer elements. These elements play e.g. an important role in the design of nuclear waste repositories. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28162 10.25643/bauhaus-universitaet.2816 Institut für Strukturmechanik (ISM) OPUS4-3300 Wissenschaftlicher Artikel Zhao, Jun-Hua; Lu, Lixin; Zhang, Zhiliang; Guo, Wanlin; Rabczuk, Timon Continuum modeling of the cohesive energy for the interfaces between _lms, spheres, coats and substrates Continuum modeling of the cohesive energy for the interfaces between _lms, spheres, coats and substrates 6 Computational Materials Science 432 438 Institut für Strukturmechanik (ISM) OPUS4-3273 Wissenschaftlicher Artikel Ben, S.; Zhao, Jun-Hua; Zhang, Yancheng; Rabczuk, Timon The interface strength and debonding for composite structures: review and recent developments The interface strength and debonding for composite structures: review and recent developments Composite Structures Institut für Strukturmechanik (ISM) OPUS4-3279 Wissenschaftlicher Artikel Zhao, Jun-Hua; Jia, Yue; Wei, Ning; Rabczuk, Timon Binding energy and mechanical stability of two parallel and crossing carbon nanotubes Binding energy and mechanical stability of two parallel and crossing carbon nanotubes Journal of Applied Mechanics Institut für Strukturmechanik (ISM) OPUS4-3290 Wissenschaftlicher Artikel Kumar, S.; Singh, I.; Mishra, B.K.; Rabczuk, Timon Modeling and Simulation of Kinked Cracks by Virtual Node XFEM Modeling and Simulation of Kinked Cracks by Virtual Node XFEM 41 Computer Methods in Applied Mechanics and Engineering 1425 1466 Institut für Strukturmechanik (ISM) OPUS4-3280 Wissenschaftlicher Artikel Jiang, Jin-Wu; Rabczuk, Timon; Park, Harold S. A Stillinger-Weber Potential for Single-Layer Black Phosphorus, and the Importance of Cross-Pucker Interactions for Negative Poisson's Ratio and Edge Stress-Induced Bending The distinguishing structural feature of single-layered black phosphorus is its puckered structure, which leads to many novel physical properties. In this work, we first present a new parameterization of the Stillinger-Weber potential for single-layered black phosphorus. In doing so, we reveal the importance of a cross-pucker interaction term in capturing its unique mechanical properties, such as a negative Poisson's ratio. In particular, we show that the cross-pucker interaction enables the pucker to act as a re-entrant hinge, which expands in the lateral direction when it is stretched in the longitudinal direction. As a consequence, single-layered black phosphorus has a negative Poisson's ratio in the direction perpendicular to the atomic plane. As an additional demonstration of the impact of the cross-pucker interaction, we show that it is also the key factor that enables capturing the edge stress-induced bending of single-layered black phosphorus that has been reported in ab initio calculations. Nanoscale 10.1039/C4NR07341J Institut für Strukturmechanik (ISM) OPUS4-3287 Wissenschaftlicher Artikel Talebi, Hossein; Silani, Mohammad; Rabczuk, Timon Concurrent Multiscale Modelling of Three Dimensional Crack and Dislocation Propagation Concurrent Multiscale Modelling of Three Dimensional Crack and Dislocation Propagation 10 Advances in Engineering Software 82 92 Institut für Strukturmechanik (ISM) OPUS4-3283 Wissenschaftlicher Artikel Ghasemi, Hamid; Brighenti, Roberto; Zhuang, Xiaoying; Muthu, Jacob; Rabczuk, Timon Optimum fiber content and distribution in fiber-reinforced solids using a reliability and NURBS based sequential optimization approach Optimum _ber content and distribution in _ber-reinforced solids using a reliability and NURBS based sequential optimization approach 13 Structural and Multidisciplinary Optimization 99 112 Institut für Strukturmechanik (ISM) OPUS4-3275 Wissenschaftlicher Artikel Areias, Pedro; Rabczuk, Timon; Cesar de Sa, J.M.; Jorge, R.N. A semi-implicit _nite strain shell algorithm using in-plane strains based on least-squares A semi-implicit _nite strain shell algorithm using in-plane strains based on least-squares Computational Mechanics Institut für Strukturmechanik (ISM) OPUS4-3291 Wissenschaftlicher Artikel Vu-Bac, N.; Silani, Mohammad; Lahmer, Tom; Zhuang, Xiaoying; Rabczuk, Timon A unified framework for stochastic predictions of Young's modulus of clay/epoxy nanocomposites (PCNs) A unified framework for stochastic predictions of Young's modulus of clay/epoxy nanocomposites (PCNs) 15 Computational Materials Science 520 535 Institut für Strukturmechanik (ISM) OPUS4-3277 Wissenschaftlicher Artikel Nanthakumar, S.S.; Lahmer, Tom; Zhuang, Xiaoying; Zi, Goangseup; Rabczuk, Timon Detection of material interfaces using a regularized level set method in piezoelectric structures Detection of material interfaces using a regularized level set method in piezoelectric structures Inverse Problems in Science and Engineering Institut für Strukturmechanik (ISM) OPUS4-3581 Wissenschaftlicher Artikel Vu-Bac, N.; Rafiee, Roham; Zhuang, Xiaoying; Lahmer, Tom; Rabczuk, Timon Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters 18 Composites Part B: Engineering 446 464 Institut für Strukturmechanik (ISM) OPUS4-2804 Konferenzveröffentlichung Jaouadi, Zouhour; Lahmer, Tom Gürlebeck, Klaus; Lahmer, Tom Topology optimization of structures subjected to multiple load cases by introducing the Epsilon constraint method A topology optimization method has been developed for structures subjected to multiple load cases (Example of a bridge pier subjected to wind loads, traffic, superstructure...). We formulate the problem as a multi-criterial optimization problem, where the compliance is computed for each load case. Then, the Epsilon constraint method (method proposed by Chankong and Haimes, 1971) is adapted. The strategy of this method is based on the concept of minimizing the maximum compliance resulting from the critical load case while the other remaining compliances are considered in the constraints. In each iteration, the compliances of all load cases are computed and only the maximum one is minimized. The topology optimization process is switching from one load to another according to the variation of the resulting compliance. In this work we will motivate and explain the proposed methodology and provide some numerical examples. 7 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28042 10.25643/bauhaus-universitaet.2804 Institut für Strukturmechanik (ISM) OPUS4-2451 Konferenzveröffentlichung Gürlebeck, Klaus; Lahmer, Tom International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar The 20th International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering will be held at the Bauhaus University Weimar from 20th till 22nd July 2015. Architects, computer scientists, mathematicians, and engineers from all over the world will meet in Weimar for an interdisciplinary exchange of experiences, to report on their results in research, development and practice and to discuss. The conference covers a broad range of research areas: numerical analysis, function theoretic methods, partial differential equations, continuum mechanics, engineering applications, coupled problems, computer sciences, and related topics. Several plenary lectures in aforementioned areas will take place during the conference. We invite architects, engineers, designers, computer scientists, mathematicians, planners, project managers, and software developers from business, science and research to participate in the conference! 230 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20150828-24515 10.25643/bauhaus-universitaet.2451 Professur Angewandte Mathematik OPUS4-3302 Wissenschaftlicher Artikel Msekh, Mohammed Abdulrazzak; Sargado, M.; Jamshidian, M.; Areias, Pedro; Rabczuk, Timon ABAQUS implementation of phase_field model for brittle fracture ABAQUS implementation of phase_field model for brittle fracture 12 Computational Materials Science 472 484 Institut für Strukturmechanik (ISM) OPUS4-3293 Wissenschaftlicher Artikel Zhao, Jiyun; Lu, Lixin; Rabczuk, Timon The tensile and shear failure behavior dependence on chain length and temperature in amorphous polymers The tensile and shear failure behavior dependence on chain length and temperature in amorphous polymers 5 Computational Materials Science 567 572 Institut für Strukturmechanik (ISM) OPUS4-2821 Konferenzveröffentlichung Tan, Fengjie; Lahmer, Tom; Siddappa, Manju Gyaraganahalll Gürlebeck, Klaus; Lahmer, Tom SECTION OPTIMIZATION AND RELIABILITY ANALYSIS OF ARCH-TYPE DAMS INCLUDING COUPLED MECHANICAL-THERMAL AND HYDRAULIC FIELDS From the design experiences of arch dams in the past, it has significant practical value to carry out the shape optimization of arch dams, which can fully make use of material characteristics and reduce the cost of constructions. Suitable variables need to be chosen to formulate the objective function, e.g. to minimize the total volume of the arch dam. Additionally a series of constraints are derived and a reasonable and convenient penalty function has been formed, which can easily enforce the characteristics of constraints and optimal design. For the optimization method, a Genetic Algorithm is adopted to perform a global search. Simultaneously, ANSYS is used to do the mechanical analysis under the coupling of thermal and hydraulic loads. One of the constraints of the newly designed dam is to fulfill requirements on the structural safety. Therefore, a reliability analysis is applied to offer a good decision supporting for matters concerning predictions of both safety and service life of the arch dam. By this, the key factors which would influence the stability and safety of arch dam significantly can be acquired, and supply a good way to take preventive measures to prolong ate the service life of an arch dam and enhances the safety of structure. 8 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28212 10.25643/bauhaus-universitaet.2821 Institut für Strukturmechanik (ISM) OPUS4-3289 Wissenschaftlicher Artikel Anitescu, Cosmin; Jia, Yue; Zhang, Yongjie; Rabczuk, Timon An isogeometric collocation method using superconvergent points An isogeometric collocation method using superconvergent points 24 Computer Methods in Applied Mechanics and Engineer-ing 1073 1097 Institut für Strukturmechanik (ISM) OPUS4-3284 Wissenschaftlicher Artikel Areias, Pedro; Rabczuk, Timon; Cesar de Sa, J.M.; Garcao, J.E. Finite strain quadrilateral shell using least-squares _t of relative Lagrangian in-plane strains Finite strain quadrilateral shell using least-squares _t of relative Lagrangian in-plane strains 14 Finite Elements in Analysis and Design 26 40 Institut für Strukturmechanik (ISM) OPUS4-3295 Wissenschaftlicher Artikel Ghasemi, Hamid; Kerfriden, Pierre; Bordas, Stéphane Pierre Alain; Muthu, Jacob; Zi, Goangseup; Rabczuk, Timon Interfacial shear stress optimization in sandwich beams with polymeric core using nonuniform distribution of reinforcing ingredients Interfacial shear stress optimization in sandwich beams with polymeric core using nonuniform distribution of reinforcing ingredients 9 Composite Structures 221 230 Institut für Strukturmechanik (ISM) OPUS4-3276 Wissenschaftlicher Artikel Jia, Yue; Zhang, Yongjie; Rabczuk, Timon A Novel Dynamic Multilevel Technique for Image Registration A Novel Dynamic Multilevel Technique for Image Registration Computers and Mathematics with Applications Institut für Strukturmechanik (ISM) OPUS4-3299 Wissenschaftlicher Artikel Areias, Pedro; Rabczuk, Timon; Queiros de Melo, F. J. M.; Cesar de Sa, J.M. Coulomb frictional contact by explicit projection in the cone for _nite displacement quasi-static problems Coulomb frictional contact by explicit projection in the cone for _nite displacement quasi-static problems 15 Computational Mechanics 57 72 Institut für Strukturmechanik (ISM) OPUS4-3301 Wissenschaftlicher Artikel Silani, Mohammad; Talebi, Hossein; Ziaei-Rad, S.; Hamouda, A.M.S.; Zi, Goangseup; Rabczuk, Timon A three dimensional Extended Arlequin Method for Dynamic Fracture A three dimensional Extended Arlequin Method for Dynamic Fracture 6 Computational Materials Science 425 431 Institut für Strukturmechanik (ISM) OPUS4-2799 Konferenzveröffentlichung Hartmann, Veronika; Smarsly, Kay; Lahmer, Tom Gürlebeck, Klaus; Lahmer, Tom ROBUST SCHEDULING IN CONSTRUCTION ENGINEERING In construction engineering, a schedule's input data, which is usually not exactly known in the planning phase, is considered deterministic when generating the schedule. As a result, construction schedules become unreliable and deadlines are often not met. While the optimization of construction schedules with respect to costs and makespan has been a matter of research in the past decades, the optimization of the robustness of construction schedules has received little attention. In this paper, the effects of uncertainties inherent to the input data of construction schedules are discussed. Possibilities are investigated to improve the reliability of construction schedules by considering alternative processes for certain tasks and by identifying the combination of processes generating the most robust schedule with respect to the makespan of a construction project. 5 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27994 10.25643/bauhaus-universitaet.2799 Professur Informatik im Bauwesen OPUS4-3286 Wissenschaftlicher Artikel Mortazavi, Bohayra; Cuniberti, G.; Rabczuk, Timon Mechanical properties and thermal conductivity of graphitic carbon nitride: A molecular dynamics study Mechanical properties and thermal conductivity of graphitic carbon nitride: A molecular dynamics study 4 Computational Materials Science 285 289 Institut für Strukturmechanik (ISM) OPUS4-3297 Wissenschaftlicher Artikel Budarapu, Pattabhi Ramaiah; Narayana, T.S.S.; Rammohan, B.; Rabczuk, Timon Directionality of sound radiation from rectangular panels Directionality of sound radiation from rectangular panels 12 Applied Acoustics 128 140 Institut für Strukturmechanik (ISM) OPUS4-3274 Wissenschaftlicher Artikel Arash, Behrouz; Rabczuk, Timon; Jiang, Jin-Wu Nanoresonators and their applications: a state of the art review Nanoresonators and their applications: a state of the art review Applied Physics Reviews Institut für Strukturmechanik (ISM) OPUS4-3285 Wissenschaftlicher Artikel Mortazavi, Bohayra; Rabczuk, Timon Multiscale modeling of heat conduction in graphene laminates Multiscale modeling of heat conduction in graphene laminates 6 Carbon 1 7 Institut für Strukturmechanik (ISM) OPUS4-3292 Wissenschaftlicher Artikel Thai, Chien H.; Nguyen-Xuan, Hung; Bordas, Stéphane Pierre Alain; Nguyen-Thanh, Nhon; Rabczuk, Timon Isogeometric analysis of laminated composite plates using the higher-order shear deformation theory Isogeometric analysis of laminated composite plates using the higher-order shear deformation theory 18 Mechanics of Advanced Materials and Structures 451 469 Institut für Strukturmechanik (ISM) OPUS4-3294 Wissenschaftlicher Artikel Yang, Shih-Wei; Budarapu, Pattabhi Ramaiah; Mahapatra, D.R.; Bordas, Stéphane Pierre Alain; Zi, Goangseup; Rabczuk, Timon A Meshless Adaptive Multiscale Method for Fracture A Meshless Adaptive Multiscale Method for Fracture 13 Computational Materials Science 382 395 Institut für Strukturmechanik (ISM) OPUS4-2822 Konferenzveröffentlichung Bargstädt, Hans-Joachim; Tarigan, Rina Sari Gürlebeck, Klaus; Lahmer, Tom RULE BASED EXPANSION OF STANDARD CONSTRUCTION PROCESSES The paper introduces a systematic construction management approach, supporting expansion of a specified construction process, both automatically and semi-automatically. Throughout the whole design process, many requirements must be taken into account in order to fulfil demands defined by clients. In implementing those demands into a design concept up to the execution plan, constraints such as site conditions, building code, and legal framework are to be considered. However, complete information, which is needed to make a sound decision, is not yet acquired in the early phase. Decisions are traditionally taken based on experience and assumptions. Due to a vast number of appropriate available solutions, particularly in building projects, it is necessary to make those decisions traceable. This is important in order to be able to reconstruct considerations and assumptions taken, should there be any changes in the future project's objectives. The research will be carried out by means of building information modelling, where rules deriving from standard logics of construction management knowledge will be applied. The knowledge comprises a comprehensive interaction amongst bidding process, cost-estimation, construction site preparation as well as specific project logistics - which are usually still separately considered. By means of these rules, favourable decision taking regarding prefabrication and in-situ implementation can be justified. Modifications depending on the available information within current design stage will consistently be traceable. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28229 10.25643/bauhaus-universitaet.2822 Institut für Konstruktiven Ingenieurbau (IKI) OPUS4-2815 Konferenzveröffentlichung Nasir, A.R.; Bargstädt, Hans-Joachim Gürlebeck, Klaus; Lahmer, Tom AMELIORATING EMPLOYABILITY IN CONSTRUCTION THROUGH BIM INNOVATION Low-skilled labor makes a significant part of the construction sector, performing daily production tasks that do not require specific technical knowledge or confirmed skills. Today, construction market demands increasing skill levels. Many jobs that were once considered to be undertaken by low or un-skilled labor, now demand some kind of formal skills. The jobs that require low skilled labor are continually decreasing due to technological advancement and globalization. Jobs that previously required little or no training now require skilful people to perform the tasks appropriately. The study aims at ameliorating employability of less skilled manpower by finding ways to instruct them for performing constructions tasks. A review of exiting task instruction methodologies in construction and the underlying gaps within them warrants an appropriate way to train and instruct low skilled workers for the tasks in construction. The idea is to ensure the required quality of construction with technological and didactic aids seeming particularly purposeful to prepare potential workers for the tasks in construction without exposing them to existing communication barriers. A BIM based technology is considered promising along with the integration of visual directives/animations to elaborate the construction tasks scheduled to be carried on site. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28157 10.25643/bauhaus-universitaet.2815 Institut für Konstruktiven Ingenieurbau (IKI) OPUS4-2810 Konferenzveröffentlichung Kraußhar, Rolf Sören; de Almeida, Regina Gürlebeck, Klaus; Lahmer, Tom FUNDAMENTALS OF A WIMAN VALIRON THEORY FOR POLYMONOGENIC FUNCTIONS In this paper we present some rudiments of a generalized Wiman-Valiron theory in the context of polymonogenic functions. In particular, we analyze the relations between different notions of growth orders and the Taylor coefficients. Our main intention is to look for generalizations of the Lindel¨of-Pringsheim theorem. In contrast to the classical holomorphic and the monogenic setting we only obtain inequality relations in the polymonogenic setting. This is due to the fact that the Almansi-Fischer decomposition of a polymonogenic function consists of different monogenic component functions where each of them can have a totally different kind of asymptotic growth behavior. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28100 10.25643/bauhaus-universitaet.2810 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-2801 Konferenzveröffentlichung Hommel, Angela; Gürlebeck, Klaus Gürlebeck, Klaus; Lahmer, Tom THE RELATIONSHIP BETWEEN LINEAR ELASTICITY THEORY AND COMPLEX FUNCTION THEORY STUDIED ON THE BASIS OF FINITE DIFFERENCES It is well-known that the solution of the fundamental equations of linear elasticity for a homogeneous isotropic material in plane stress and strain state cases can be equivalently reduced to the solution of a biharmonic equation. The discrete version of the Theorem of Goursat is used to describe the solution of the discrete biharmonic equation by the help of two discrete holomorphic functions. In order to obtain a Taylor expansion of discrete holomorphic functions we introduce a basis of discrete polynomials which fulfill the so-called Appell property with respect to the discrete adjoint Cauchy-Riemann operator. All these steps are very important in the field of fracture mechanics, where stress and displacement fields in the neighborhood of singularities caused by cracks and notches have to be calculated with high accuracy. Using the sum representation of holomorphic functions it seems possible to reproduce the order of singularity and to determine important mechanical characteristics. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28010 10.25643/bauhaus-universitaet.2801 In Zusammenarbeit mit der Bauhaus-Universität Weimar OPUS4-3281 Wissenschaftlicher Artikel Hamdia, Khader; Lahmer, Tom; Nguyen-Thoi, T.; Rabczuk, Timon Predicting The Fracture Toughness of PNCs: A Stochastic Approach Based on ANN and ANFIS Predicting The Fracture Toughness of PNCs: A Stochastic Approach Based on ANN and ANFIS 9 Computational Materials Science 304 313 Institut für Strukturmechanik (ISM) OPUS4-2806 Konferenzveröffentlichung Kavrakov, Igor; Timmler, Hans-Georg; Morgenthal, Guido Gürlebeck, Klaus; Lahmer, Tom STRUCTURAL OPTIMIZATION USING THE ENERGY METHOD WITH INTEGRAL MATERIAL BEHAVIOUR With the advances of the computer technology, structural optimization has become a prominent field in structural engineering. In this study an unconventional approach of structural optimization is presented which utilize the Energy method with Integral Material behaviour (EIM), based on the Lagrange's principle of minimum potential energy. The equilibrium condition with the EIM, as an alternative method for nonlinear analysis, is secured through minimization of the potential energy as an optimization problem. Imposing this problem as an additional constraint on a higher cost function of a structural property, a bilevel programming problem is formulated. The nested strategy of solution of the bilevel problem is used, treating the energy and the upper objective function as separate optimization problems. Utilizing the convexity of the potential energy, gradient based algorithms are employed for its minimization and the upper cost function is minimized using the gradient free algorithms, due to its unknown properties. Two practical examples are considered in order to prove the efficiency of the method. The first one presents a sizing problem of I steel section within encased composite cross section, utilizing the material nonlinearity. The second one is a discrete shape optimization of a steel truss bridge, which is compared to a previous study based on the Finite Element Method. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28065 10.25643/bauhaus-universitaet.2806 Graduiertenkolleg 1462 OPUS4-3296 Wissenschaftlicher Artikel Nguyen-Thanh, Nhon; Valizadeh, Navid; Nguyen, Manh Hung; Nguyen-Xuan, Hung; Zhuang, Xiaoying; Areias, Pedro; Zi, Goangseup; Bazilevs, Yuri; De Lorenzis, Laura; Rabczuk, Timon An extended isogeometric thin shell analysis based on Kirchhoff-Love theory An extended isogeometric thin shell analysis based on Kirchho_-Love theory 26 Computer Methods in Applied Mechanics and Engineering 265 291 Institut für Strukturmechanik (ISM) OPUS4-2807 Konferenzveröffentlichung Kersten, Jens; Rodehorst, Volker Gürlebeck, Klaus; Lahmer, Tom TOWARDS STEREO VISION- AND LASER SCANNER-BASED UAS POSE ESTIMATION A central issue for the autonomous navigation of mobile robots is to map unknown environments while simultaneously estimating its position within this map. This chicken-eggproblem is known as simultaneous localization and mapping (SLAM). Asctec's quadrotor Pelican is a powerful and flexible research UAS (unmanned aircraft system) which enables the development of new real-time on-board algorithms for SLAM as well as autonomous navigation. The relative UAS pose estimation for SLAM, usually based on low-cost sensors like inertial measurement units (IMU) and barometers, is known to be affected by high drift rates. In order to significantly reduce these effects, we incorporate additional independent pose estimation techniques using exteroceptive sensors. In this article we present first pose estimation results using a stereo camera setup as well as a laser range finder, individually. Even though these methods fail in few certain configurations we demonstrate their effectiveness and value for the reduction of IMU drift rates and give an outlook for further works towards SLAM. 7 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28072 10.25643/bauhaus-universitaet.2807 Professur Angewandte Mathematik OPUS4-3282 Wissenschaftlicher Artikel Rabizadeh, Ehsan; Saboor Bagherzadeh, Amir; Rabczuk, Timon Application of goal-oriented error estimation and adaptive mesh refinement on thermo-mechanical multifield problems Application of goal-oriented error estimation and adaptive mesh re_nement on thermo-mechanical multi_eld problems 17 Computational Materials Science 27 44 Institut für Strukturmechanik (ISM) OPUS4-3298 Wissenschaftlicher Artikel Ghorashi, Seyed Shahram; Valizadeh, Navid; Mohammadi, S.; Rabczuk, Timon T-spline based XIGA for Fracture Analysis of Orthotropic Media T-spline based XIGA for Fracture Analysis of Orthotropic Media 8 Computers & Structures 138 146 Institut für Strukturmechanik (ISM) OPUS4-2793 Konferenzveröffentlichung Alalade, Muyiwa; Kafle, Binod; Wuttke, Frank; Lahmer, Tom Gürlebeck, Klaus; Lahmer, Tom CALIBRATION OF CYCLIC CONSTITUTIVE MODELS FOR SOILS BY OSCILLATING FUNCTIONS In order to minimize the probability of foundation failure resulting from cyclic action on structures, researchers have developed various constitutive models to simulate the foundation response and soil interaction as a result of these complex cyclic loads. The efficiency and effectiveness of these model is majorly influenced by the cyclic constitutive parameters. Although a lot of research is being carried out on these relatively new models, little or no details exist in literature about the model based identification of the cyclic constitutive parameters. This could be attributed to the difficulties and complexities of the inverse modeling of such complex phenomena. A variety of optimization strategies are available for the solution of the sum of least-squares problems as usually done in the field of model calibration. However for the back analysis (calibration) of the soil response to oscillatory load functions, this paper gives insight into the model calibration challenges and also puts forward a method for the inverse modeling of cyclic loaded foundation response such that high quality solutions are obtained with minimum computational effort. Therefore model responses are produced which adequately describes what would otherwise be experienced in the laboratory or field. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-27932 10.25643/bauhaus-universitaet.2793 Professur Angewandte Mathematik OPUS4-2808 Konferenzveröffentlichung Khosravian, Reza; Wuttke, Frank Gürlebeck, Klaus; Lahmer, Tom QUALITATIVE INVESTIGATION OF THE EFFECT OF SOIL MODELING APPROACH ON DYNAMIC BEHAVIOR OF A SMALL-SCALE 2-DOF STRUCTURE WITH PILE FOUNDATION Known as a sophisticated phenomenon in civil engineering problems, soil structure interaction has been under deep investigations in the field of Geotechnics. On the other hand, advent of powerful computers has led to development of numerous numerical methods to deal with this phenomenon, resulting in a wide variety of methods trying to simulate the behavior of the soil stratum. This survey studies two common approaches to model the soil's behavior in a system consisting of a structure with two degrees of freedom, representing a two-storey frame structure made of steel, with the column resting on a pile embedded into sand in laboratory scale. The effect of soil simulation technique on the dynamic behavior of the structure is of major interest in the study. Utilized modeling approaches are the so-called Holistic method, and substitution of soil with respective impedance functions. 6 Digital Proceedings, International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering : July 20 - 22 2015, Bauhaus-University Weimar urn:nbn:de:gbv:wim2-20170314-28080 10.25643/bauhaus-universitaet.2808 Graduiertenkolleg 1462 OPUS4-3314 Wissenschaftlicher Artikel Xu, G.; Mourrain, B.; Galligo, A.; Rabczuk, Timon High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods Computational Mechanics Institut für Strukturmechanik (ISM) OPUS4-3312 Wissenschaftlicher Artikel Silani, Mohammad; Ziaei-Rad, S.; Talebi, Hossein; Rabczuk, Timon A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites Theoretical and Applied Fracture Mechanics Institut für Strukturmechanik (ISM) OPUS4-3336 Wissenschaftlicher Artikel Amani, Jafar; Bagherzadeh, Amir Saboor; Rabczuk, Timon Error estimate and adaptive refinement in Mixed Discrete Least Squares Meshless method Error estimate and adaptive refinement in Mixed Discrete Least Squares Meshless method Mathematical Problems in Engineering Institut für Strukturmechanik (ISM) OPUS4-3319 Wissenschaftlicher Artikel Zhao, Jiyun; Jiang, Jin-Wu; Wang, L.; Guo, Wanlin; Rabczuk, Timon Coarse-grained potentials of single-walled carbon nanotubes Coarse-grained potentials of single-walled carbon nanotubes Journal of the Mechanics and Physics of Solids Institut für Strukturmechanik (ISM) OPUS4-3320 Wissenschaftlicher Artikel Areias, Pedro; Rabczuk, Timon; Barbosa, J.I. The extended unsymmetric frontal solution for multiple-point constraints The extended unsymmetric frontal solution for multiple-point constraints Engineering Computations Institut für Strukturmechanik (ISM) OPUS4-3332 Wissenschaftlicher Artikel Vu-Bac, N.; Lahmer, Tom; Zhang, Yancheng; Zhuang, Xiaoying; Rabczuk, Timon Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs) Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs) 15 Composites Part B Engineering 80 95 Institut für Strukturmechanik (ISM) OPUS4-3323 Wissenschaftlicher Artikel Joshi, Suraj; Hildebrand, Jörg; Aloraier, Abdulkareem S.; Rabczuk, Timon Characterization of material properties and heat source parameters in welding simulation of two overlapping beads on a substrate plate This paper presents several aspects of characterization of welding heat source parameters in Goldak's double ellipsoidal model using Sysweld simulation of welding of two overlapping beads on a substrate steel plate. The overlap percentages ranged from 40% to 80% in increments of 10%. The new material properties of the fused metal were characterized using Weldware and their continuous cooling transformation curves. The convective and radiative heat transfer coefficients as well as the cooling time t8/5 were estimated using numerical formulations from relevant standards. The effects of the simulation geometry and mesh discretization were evaluated in terms of the factor F provided in Sysweld. Eventually, the parameters of Goldak's double ellipsoidal heat source model were determined for the welding simulation of overlapping beads on the plate and the simulated bead geometry, extent of the molten pool and the HAZ were compared with the macrographs of cross-sections of the experimental weldments. The results showed excellent matching, thus verifying this methodology for determination of welding heat source parameters. 6 Computational Materials Science 559 565 10.1016/j.commatsci.2012.11.029 Institut für Strukturmechanik (ISM) OPUS4-3322 Wissenschaftlicher Artikel Zhao, Jun-Hua; Jiang, Jin-Wu; Jia, Yue; Guo, Wanlin; Rabczuk, Timon A theoretical analysis of cohesive energy between carbon nanotubes, graphene and substrates Explicit solutions for the cohesive energy between carbon nanotubes, graphene and substrates are obtained through continuum modeling of the van der Waals interaction between them. The dependence of the cohesive energy on their size, spacing and crossing angles is analyzed. Checking against full atom molecular dynamics calculations and available experimental results shows that the continuum solution has high accuracy. The equilibrium distances between the nanotubes, graphene and substrates with minimum cohesive energy are also provided explicitly. The obtained analytical solution should be of great help for understanding the interaction between the nanostructures and substrates, and designing composites and nanoelectromechanical systems. 11 Carbon 108 119 10.1016/j.carbon.2013.01.041 Institut für Strukturmechanik (ISM) OPUS4-3311 Wissenschaftlicher Artikel Zhao, Jun-Hua; Kou, Liangzhi; Jiang, Jin-Wu; Rabczuk, Timon Tension-induced phase transition of single-layer molybdenum disulphide (MoS2) at low temperatures Tension-induced phase transition of single-layer molybdenum disulphide (MoS2) at low temperatures Nanotechnology 10.1088/0957-4484/25/29/295701 Institut für Strukturmechanik (ISM) OPUS4-3341 Wissenschaftlicher Artikel Ghasemi, Hamid; Rafiee, Roham; Zhuang, Xiaoying; Muthu, Jacob; Rabczuk, Timon Uncertainties propagation in metamodel-based probabilistic optimization of CNT/polymer composite structure using stochastic multi-scale modeling Uncertainties propagation in metamodel-based probabilistic optimization of CNT/polymer composite structure using stochastic multi-scale modeling 10 Computational Materials Science 295 305 Institut für Strukturmechanik (ISM) OPUS4-3330 Wissenschaftlicher Artikel Zhang, Yancheng; Zhuang, Xiaoying; Muthu, Jacob; Mabrouki, Tarek; Fontaine, Michaël; Gong, Yadong; Rabczuk, Timon Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation 6 Composites Part B Engineering 27 33 Institut für Strukturmechanik (ISM) OPUS4-3337 Wissenschaftlicher Artikel Nguyen-Thanh, Nhon; Muthu, Jacob; Zhuang, Xiaoying; Rabczuk, Timon An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics 16 Computational Mechanics 369 385 Institut für Strukturmechanik (ISM) OPUS4-3331 Wissenschaftlicher Artikel Jiang, Jin-Wu; Wang, Bing-Shen; Rabczuk, Timon Phonon modes in single-walled molybdenum disulphide nanotubes: lattice dynamics calculation and molecular dynamics simulation Phonon modes in single-walled molybdenum disulphide nanotubes: lattice dynamics calculation and molecular dynamics simulation Nanotechnology Institut für Strukturmechanik (ISM) OPUS4-3326 Wissenschaftlicher Artikel Zhao, Jun-Hua; Lu, Lixin; Rabczuk, Timon Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines The Journal of Chemical Physics 10.1063/1.4878115 Institut für Strukturmechanik (ISM) OPUS4-3340 Wissenschaftlicher Artikel Ghasemi, Hamid; Brighenti, Roberto; Zhuang, Xiaoying; Muthu, Jacob; Rabczuk, Timon Optimization of fiber distribution in fiber reinforced composite by using NURBS functions Optimization of fiber distribution in fiber reinforced composite by using NURBS functions 10 Computational Materials Science 463 473 Institut für Strukturmechanik (ISM) OPUS4-3333 Wissenschaftlicher Artikel Jamshidian, M.; Rabczuk, Timon Phase field modelling of stressed grain growth: Analytical study and the effect of microstructural length scale Phase field modelling of stressed grain growth: Analytical study and the effect of microstructural length scale 12 Journal of Computational Physics 23 35 Institut für Strukturmechanik (ISM)