@article{NagelSimonKuemmeletal., author = {Nagel, Falk and Simon, Flaviu and K{\"u}mmel, Benjamin and Bergmann, Jean Pierre and Hildebrand, J{\"o}rg}, title = {Optimization Strategies for Laser Welding High Alloy Steel Sheets}, series = {Physics Procedia}, journal = {Physics Procedia}, doi = {10.1016/j.phpro.2014.08.040}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31554}, pages = {1242 -- 1251}, abstract = {A known phenomenon during laser welding of thin sheets is the deformation caused by thermally induced stresses. This deformation can result in a change of the gap width between the welded parts, which leads to an unstable welding process. Inducing displacements by using a second heat source will compensate for the change in gap width, hence optimizing the welding process. The base material is 1 mm thick austenitic stainless steel 1.4301, which is welded by a CO2 laser. The second heat source is a diode laser. The gap between the welded parts was set between 0.05 mm and 0.1 mm. The influence of the second heat source on the welding process and the welding result is described. The usage of a second heat source allows a higher gap width to be set prior to the welding process. The results of the numerical simulation were found to be corresponding to those of the experiments.}, subject = {Edelstahl}, language = {en} } @article{LinnowNiermannBonatzetal., author = {Linnow, Kirsten and Niermann, Michael and Bonatz, Dennis and Posern, Konrad and Steiger, Michael}, title = {Experimental Studies of the Mechanism and Kinetics of Hydration Reactions}, series = {Energy Procedia}, journal = {Energy Procedia}, doi = {10.1016/j.egypro.2014.02.046}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31484}, pages = {394 -- 404}, abstract = {The mechanism and the kinetics of hydration reactions are important for the application of a salt hydrate as a thermochemical heat storage material. MgSO4·H2O and Na2SO4 were chosen in this study because they are both promising candidates for such an application. Considering that the hydration of these salts yields MgSO4·7H2O and Na2SO4·10H2O as the reaction products, the maximum overall heat effect can be calculated from the heat of condensation of water vapor (44 kJ mol-1) and the heats of hydration of 75 kJ·mol-1 (for MgSO4·H2O) and 81 kJ mol-1 (for Na2SO4). Based on the densities of the two hydrated phases, this results in the very high theoretical energy densities of 2.3 GJ·m-3 and 2.4 GJ·m-3, respectively, for MgSO4·7H2O and Na2SO4·10H2O. Not only the energy density is important for the dimensioning of a storage system, but also the kinetics of hydration reactions play a major role for the application as storage material. In the present study, hydration reactions under varying climatic conditions were investigated by using water vapor sorption measurements and in-situ Raman microscopy. Using the phase diagrams, it can be clearly shown that the mechanism and the kinetics depend on the climatic conditions. Below the deliquescence humidity of the lower hydrated phase the hydration proceeds as solid state reaction, whilst above the deliquescence humidity a through solution mechanism takes place.}, subject = {W{\"a}rmespeicherung}, language = {en} } @article{AtaollahiOshkourTalebiSeyedShirazietal., author = {Ataollahi Oshkour, Azim and Talebi, Hossein and Seyed Shirazi, Seyed Farid and Bayat, Mehdi and Yau, Yat Huang and Tarlochan, Faris and Abu Osman, Noor Azuan}, title = {Comparison of various functionally graded femoral prostheses by finite element analysis}, series = {Scientific World Journal}, journal = {Scientific World Journal}, doi = {10.1155/2014/807621}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170413-31194}, abstract = {This study is focused on finite element analysis of a model comprising femur into which a femoral component of a total hip replacement was implanted. The considered prosthesis is fabricated from a functionally graded material (FGM) comprising a layer of a titanium alloy bonded to a layer of hydroxyapatite. The elastic modulus of the FGM was adjusted in the radial, longitudinal, and longitudinal-radial directions by altering the volume fraction gradient exponent. Four cases were studied, involving two different methods of anchoring the prosthesis to the spongy bone and two cases of applied loading. The results revealed that the FG prostheses provoked more SED to the bone. The FG prostheses carried less stress, while more stress was induced to the bone and cement. Meanwhile, less shear interface stress was stimulated to the prosthesis-bone interface in the noncemented FG prostheses. The cement-bone interface carried more stress compared to the prosthesis-cement interface. Stair climbing induced more harmful effects to the implanted femur components compared to the normal walking by causing more stress. Therefore, stress shielding, developed stresses, and interface stresses in the THR components could be adjusted through the controlling stiffness of the FG prosthesis by managing volume fraction gradient exponent.}, subject = {Finite-Elemente-Methode}, language = {en} } @article{MasoodKharalNasir, author = {Masood, R. and Kharal, M. K. N. and Nasir, A.R.}, title = {Is BIM Adoption Advantageous for Construction Industry of Pakistan?}, series = {Procedia Engineering}, journal = {Procedia Engineering}, doi = {10.1016/j.proeng.2014.07.021}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31509}, pages = {229 -- 238}, abstract = {Lack of Information technology applications on construction projects lead to complex flow of data during project life cycle. Building Information Modeling (BIM) has gained attention in the Architectural, Engineering and Construction (AEC) industry, envisage the use of virtual n-dimensional (n-D) models to identify potential conflicts in design, construction or operational of any facility. A questionnaire has been designed to investigate perceptions regarding BIM advantages. Around 102 valid responses received from diversified stakeholders. Results showed very low BIM adoption with low level of 'Buzz'. BIM is a faster and more effective method for designing and construction management, it improves quality of the design and construction and reduces rework during construction; which came out as the top thee advantages according to the perception of AEC professionals of Pakistan.BIM has least impact on reduction of cost, time and human resources. This research is a bench mark study to understand adoption and advantageous of BIM in Pakistan Construction Industry.}, subject = {Building Information Modeling}, language = {en} } @article{Massaretti, author = {Massaretti, Pier Giorgio}, title = {Dagli inizi dell'urbanismo teorico alla citt{\`a} moderna. Visioni urbanistiche del totalitarismo - Italia}, series = {Anthologie zum St{\"a}dtebau. Das Ph{\"a}nomen Großstadt und die Entstehung der Stadt der Moderne}, journal = {Anthologie zum St{\"a}dtebau. Das Ph{\"a}nomen Großstadt und die Entstehung der Stadt der Moderne}, doi = {10.25643/bauhaus-universitaet.3222}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170529-32228}, pages = {1 -- 45}, abstract = {La prima edizione di questo testo {\`e} apparsa, in tedesco, nel volume II.2.: Anthologie zum St{\"a}dtebau. Das Ph{\"a}nomen Großstadt und die Entstehung der Stadt der Moderne, a cura di Vittorio Magnago Lampugnani, Katia Frey, Eliana Perotti, con il sostegno di Departement Architektur der Eidgen{\"o}ssischen Technischen Hochschule, Z{\"u}rich (Gebr. Mann Verlag, Berlin 2014, pp. 1307-1390). Previ specifici accordi con l'editore, viene qui presentata la versione originaria, in italiano, dell'intero capitolo: Modernit{\"a}t und Emphase. St{\"a}dtebau im italienischen Faschismus, e comprendente: i) una capiente saggio introduttivo - in una versione pi{\`u} ampia ed articolata (comprensiva della "Bibliografia sistematica", di riferimento) del testo in tedesco; ii) la versione in italiano del repertorio antologico di riferimento - e comprensiva di una "Scheda introduttiva", sull'Autore-Opera, e di una selezione del testo in esame.}, subject = {St{\"a}dtebau}, language = {it} } @article{AdamatzkySchubert, author = {Adamatzky, Andrew and Schubert, Theresa}, title = {Slime mold microfluidic logical gates}, series = {Materials Today}, journal = {Materials Today}, doi = {10.1016/j.mattod.2014.01.018}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170413-31168}, pages = {86 -- 91}, abstract = {We demonstrate how logical operations can be implemented in ensembles of protoplasmic tubes of acellular slime mold Physarum polycephalum. The tactile response of the protoplasmic tubes is used to actuate analogs of two- and four-input logical gates and memory devices. The slime mold tube logical gates display results of logical operations by blocking flow in mechanically stimulated tube fragments and redirecting the flow to output tube fragments. We demonstrate how XOR and NOR gates are constructed. We also exemplify circuits of hybrid gates and a memory device. The slime mold based gates are non-electronic, simple and inexpensive, and several gates can be realized simultaneously at sites where protoplasmic tubes merge.}, subject = {Physarum polycephalum}, language = {en} } @article{VoelkerMaempelKornadt, author = {V{\"o}lker, Conrad and M{\"a}mpel, Silvio and Kornadt, Oliver}, title = {Measuring the human body's micro-climate using a thermal manikin}, series = {Indoor Air}, journal = {Indoor Air}, number = {24, 6}, doi = {10.25643/bauhaus-universitaet.3815}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20181025-38153}, pages = {567 -- 579}, abstract = {The human body is surrounded by a micro-climate which results from its convective release of heat. In this study, the air temperature and flow velocity of this micro-climate were measured in a climate chamber at various room temperatures, using a thermal manikin simulating the heat release of the human being. Different techniques (Particle Streak Tracking, thermography, anemometry, and thermistors) were used for measurement and visualization. The manikin surface temperature was adjusted to the particular indoor climate based on simulations with a thermoregulation model (UCBerkeley Thermal Comfort Model). We found that generally, the micro-climate is thinner at the lower part of the torso, but expands going up. At the head, there is a relatively thick thermal layer, which results in an ascending plume above the head. However, the micro-climate shape strongly depends not only on the body segment, but also on boundary conditions: the higher the temperature difference between the surface temperature of the manikin and the air temperature, the faster the air flow in the micro-climate. Finally, convective heat transfer coefficients strongly increase with falling room temperature, while radiative heat transfer coefficients decrease. The type of body segment strongly influences the convective heat transfer coefficient, while only minimally influencing the radiative heat transfer coefficient.}, subject = {Raumklima}, language = {en} } @article{MotraHildebrandDimmigOsburg, author = {Motra, Hem Bahadur and Hildebrand, J{\"o}rg and Dimmig-Osburg, Andrea}, title = {Assessment of strain measurement techniques to characterise mechanical properties of structural steel}, series = {Engineering Science and Technology, an International Journal}, journal = {Engineering Science and Technology, an International Journal}, doi = {10.1016/j.jestch.2014.07.006}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31540}, pages = {260 -- 269}, abstract = {Strain measurement is important in mechanical testing. A wide variety of techniques exists for measuring strain in the tensile test; namely the strain gauge, extensometer, stress and strain determined by machine crosshead motion, Geometric Moire technique, optical strain measurement techniques and others. Each technique has its own advantages and disadvantages. The purpose of this study is to quantitatively compare the strain measurement techniques. To carry out the tensile test experiments for S 235, sixty samples were cut from the web of the I-profile in longitudinal and transverse directions in four different dimensions. The geometry of samples are analysed by 3D scanner and vernier caliper. In addition, the strain values were determined by using strain gauge, extensometer and machine crosshead motion. Three techniques of strain measurement are compared in quantitative manner based on the calculation of mechanical properties (modulus of elasticity, yield strength, tensile strength, percentage elongation at maximum force) of structural steel. A statistical information was used for evaluating the results. It is seen that the extensometer and strain gauge provided reliable data, however the extensometer offers several advantages over the strain gauge and crosshead motion for testing structural steel in tension. Furthermore, estimation of measurement uncertainty is presented for the basic material parameters extracted through strain measurement.}, subject = {Baustahl}, language = {en} } @article{XuMourrainGalligoetal., author = {Xu, G. and Mourrain, B. and Galligo, A. and Rabczuk, Timon}, title = {High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods}, series = {Computational Mechanics}, journal = {Computational Mechanics}, abstract = {High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods}, subject = {Angewandte Mathematik}, language = {en} } @article{SilaniZiaeiRadTalebietal., author = {Silani, Mohammad and Ziaei-Rad, S. and Talebi, Hossein and Rabczuk, Timon}, title = {A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites}, series = {Theoretical and Applied Fracture Mechanics}, journal = {Theoretical and Applied Fracture Mechanics}, abstract = {A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites}, subject = {Angewandte Mathematik}, language = {en} } @article{AmaniBagherzadehRabczuk, author = {Amani, Jafar and Bagherzadeh, Amir Saboor and Rabczuk, Timon}, title = {Error estimate and adaptive refinement in Mixed Discrete Least Squares Meshless method}, series = {Mathematical Problems in Engineering}, journal = {Mathematical Problems in Engineering}, abstract = {Error estimate and adaptive refinement in Mixed Discrete Least Squares Meshless method}, subject = {Angewandte Mathematik}, language = {en} } @article{ZhaoJiangWangetal., author = {Zhao, Jiyun and Jiang, Jin-Wu and Wang, L. and Guo, Wanlin and Rabczuk, Timon}, title = {Coarse-grained potentials of single-walled carbon nanotubes}, series = {Journal of the Mechanics and Physics of Solids}, journal = {Journal of the Mechanics and Physics of Solids}, abstract = {Coarse-grained potentials of single-walled carbon nanotubes}, subject = {Angewandte Mathematik}, language = {en} } @article{AreiasRabczukBarbosa, author = {Areias, Pedro and Rabczuk, Timon and Barbosa, J.I.}, title = {The extended unsymmetric frontal solution for multiple-point constraints}, series = {Engineering Computations}, journal = {Engineering Computations}, abstract = {The extended unsymmetric frontal solution for multiple-point constraints}, subject = {Angewandte Mathematik}, language = {en} } @article{VuBacLahmerZhangetal., author = {Vu-Bac, N. and Lahmer, Tom and Zhang, Yancheng and Zhuang, Xiaoying and Rabczuk, Timon}, title = {Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs)}, series = {Composites Part B Engineering}, journal = {Composites Part B Engineering}, pages = {80 -- 95}, abstract = {Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs)}, subject = {Angewandte Mathematik}, language = {en} } @article{JoshiHildebrandAloraieretal., author = {Joshi, Suraj and Hildebrand, J{\"o}rg and Aloraier, Abdulkareem S. and Rabczuk, Timon}, title = {Characterization of material properties and heat source parameters in welding simulation of two overlapping beads on a substrate plate}, series = {Computational Materials Science}, journal = {Computational Materials Science}, doi = {10.1016/j.commatsci.2012.11.029}, pages = {559 -- 565}, abstract = {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.}, subject = {Angewandte Mathematik}, language = {en} } @article{ZhaoJiangJiaetal., author = {Zhao, Jun-Hua and Jiang, Jin-Wu and Jia, Yue and Guo, Wanlin and Rabczuk, Timon}, title = {A theoretical analysis of cohesive energy between carbon nanotubes, graphene and substrates}, series = {Carbon}, journal = {Carbon}, doi = {10.1016/j.carbon.2013.01.041}, pages = {108 -- 119}, abstract = {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.}, subject = {Angewandte Mathematik}, language = {en} } @article{ZhaoKouJiangetal., author = {Zhao, Jun-Hua and Kou, Liangzhi and Jiang, Jin-Wu and Rabczuk, Timon}, title = {Tension-induced phase transition of single-layer molybdenum disulphide (MoS2) at low temperatures}, series = {Nanotechnology}, journal = {Nanotechnology}, doi = {10.1088/0957-4484/25/29/295701}, abstract = {Tension-induced phase transition of single-layer molybdenum disulphide (MoS2) at low temperatures}, subject = {Angewandte Mathematik}, language = {en} } @article{GhasemiRafieeZhuangetal., author = {Ghasemi, Hamid and Rafiee, Roham and Zhuang, Xiaoying and Muthu, Jacob and Rabczuk, Timon}, title = {Uncertainties propagation in metamodel-based probabilistic optimization of CNT/polymer composite structure using stochastic multi-scale modeling}, series = {Computational Materials Science}, journal = {Computational Materials Science}, pages = {295 -- 305}, abstract = {Uncertainties propagation in metamodel-based probabilistic optimization of CNT/polymer composite structure using stochastic multi-scale modeling}, subject = {Angewandte Mathematik}, language = {en} } @article{ZhangZhuangMuthuetal., author = {Zhang, Yancheng and Zhuang, Xiaoying and Muthu, Jacob and Mabrouki, Tarek and Fontaine, Micha{\"e}l and Gong, Yadong and Rabczuk, Timon}, title = {Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation}, series = {Composites Part B Engineering}, journal = {Composites Part B Engineering}, pages = {27 -- 33}, abstract = {Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation}, subject = {Angewandte Mathematik}, language = {en} } @article{NguyenThanhMuthuZhuangetal., author = {Nguyen-Thanh, Nhon and Muthu, Jacob and Zhuang, Xiaoying and Rabczuk, Timon}, title = {An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics}, series = {Computational Mechanics}, journal = {Computational Mechanics}, pages = {369 -- 385}, abstract = {An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics}, subject = {Angewandte Mathematik}, language = {en} } @article{JiangWangRabczuk, author = {Jiang, Jin-Wu and Wang, Bing-Shen and Rabczuk, Timon}, title = {Phonon modes in single-walled molybdenum disulphide nanotubes: lattice dynamics calculation and molecular dynamics simulation}, series = {Nanotechnology}, journal = {Nanotechnology}, abstract = {Phonon modes in single-walled molybdenum disulphide nanotubes: lattice dynamics calculation and molecular dynamics simulation}, subject = {Angewandte Mathematik}, language = {en} } @article{ZhaoLuRabczuk, author = {Zhao, Jun-Hua and Lu, Lixin and Rabczuk, Timon}, title = {Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines}, series = {The Journal of Chemical Physics}, journal = {The Journal of Chemical Physics}, doi = {10.1063/1.4878115}, abstract = {Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines}, subject = {Angewandte Mathematik}, language = {en} } @article{GhasemiBrighentiZhuangetal., author = {Ghasemi, Hamid and Brighenti, Roberto and Zhuang, Xiaoying and Muthu, Jacob and Rabczuk, Timon}, title = {Optimization of fiber distribution in fiber reinforced composite by using NURBS functions}, series = {Computational Materials Science}, journal = {Computational Materials Science}, pages = {463 -- 473}, abstract = {Optimization of fiber distribution in fiber reinforced composite by using NURBS functions}, subject = {Angewandte Mathematik}, language = {en} } @article{JamshidianRabczuk, author = {Jamshidian, M. and Rabczuk, Timon}, title = {Phase field modelling of stressed grain growth: Analytical study and the effect of microstructural length scale}, series = {Journal of Computational Physics}, journal = {Journal of Computational Physics}, pages = {23 -- 35}, abstract = {Phase field modelling of stressed grain growth: Analytical study and the effect of microstructural length scale}, subject = {Angewandte Mathematik}, language = {en} } @article{ThaiFerreiraBordasetal., author = {Thai, Chien H. and Ferreira, A.J.M. and Bordas, St{\´e}phane Pierre Alain and Rabczuk, Timon and Nguyen-Xuan, Hung}, title = {Isogeometric analysis of laminated composite and sandwich plates using a new inverse trigonometric shear deformation theory}, series = {European Journal of Mechanics}, journal = {European Journal of Mechanics}, pages = {89 -- 108}, abstract = {Isogeometric analysis of laminated composite and sandwich plates using a new inverse trigonometric shear deformation theory}, subject = {Angewandte Mathematik}, language = {en} } @article{GhasemiBrighentiZhuangetal., author = {Ghasemi, Hamid and Brighenti, Roberto and Zhuang, Xiaoying and Muthu, Jacob and Rabczuk, Timon}, title = {Sequential reliability based optimization of fiber content and dispersion in fiber reinforced composite by using NURBS finite elements}, series = {Structural and Multidisciplinary Optimization}, journal = {Structural and Multidisciplinary Optimization}, abstract = {Sequential reliability based optimization of fiber content and dispersion in fiber reinforced composite by using NURBS finite elements}, subject = {Angewandte Mathematik}, language = {en} } @article{ChenNguyenThanhNguyenXuanetal., author = {Chen, Lei and Nguyen-Thanh, Nhon and Nguyen-Xuan, Hung and Rabczuk, Timon and Bordas, St{\´e}phane Pierre Alain and Limbert, Georges}, title = {Explicit finite deformation analysis of isogeometric membranes}, series = {Computer Methods in Applied Mechanics and Engineering}, journal = {Computer Methods in Applied Mechanics and Engineering}, pages = {104 -- 130}, abstract = {Explicit finite deformation analysis of isogeometric membranes}, subject = {Angewandte Mathematik}, language = {en} } @article{LeNguyenLudwig, author = {Le, Ha Thanh and Nguyen, Sang Thanh and Ludwig, Horst-Michael}, title = {A Study on High Performance Fine-Grained Concrete Containing Rice Husk Ash}, series = {International Journal of Concrete Structures and Materials}, journal = {International Journal of Concrete Structures and Materials}, doi = {10.1007/s40069-014-0078-z}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170425-31477}, pages = {301 -- 307}, abstract = {Rice husk ash (RHA) is classified as a highly reactive pozzolan. It has a very high silica content similar to that of silica fume (SF). Using less-expensive and locally available RHA as a mineral admixture in concrete brings ample benefits to the costs, the technical properties of concrete as well as to the environment. An experimental study of the effect of RHA blending on workability, strength and durability of high performance fine-grained concrete (HPFGC) is presented. The results show that the addition of RHA to HPFGC improved significantly compressive strength, splitting tensile strength and chloride penetration resistance. Interestingly, the ratio of compressive strength to splitting tensile strength of HPFGC was lower than that of ordinary concrete, especially for the concrete made with 20 \% RHA. Compressive strength and splitting tensile strength of HPFGC containing RHA was similar and slightly higher, respectively, than for HPFGC containing SF. Chloride penetration resistance of HPFGC containing 10-15 \% RHA was comparable with that of HPFGC containing 10 \% SF.}, subject = {Hochfester Beton}, language = {en} } @article{KoenigStandfestSchmitt, author = {K{\"o}nig, Reinhard and Standfest, Matthias and Schmitt, Gerhard}, title = {Evolutionary multi-criteria optimization for building layout planning: Exemplary application based on the PSSA framework}, series = {32nd eCAADe Conference - Volume 2}, journal = {32nd eCAADe Conference - Volume 2}, editor = {Thompson, Emine Mine}, doi = {10.25643/bauhaus-universitaet.2513}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20160121-25139}, pages = {567 -- 574}, abstract = {When working on urban planning projects there are usually multiple aspects to consider. Often these aspects are contradictory and it is not possible to choose one over the other; instead, they each need to be fulfilled as well as possible. Planners typically draw on past experience when subjectively prioritising which aspects to consider with which degree of importance for their planning concepts. This practice, although understandable, places power and authority in the hands of people who have varying degrees of expertise, which means that the best possible solution is not always found, because it is either not sought or the problem is regarded as being too complex for human capabilities. To improve this situation, the project presented here shows the potential of multi-criteria optimisation algorithms using the example of a new housing layout for an urban block. In addition it is shown, how Self-Organizing-Maps can be used to visualise multi-dimensional solution spaces in an easy analysable and comprehensible form.}, subject = {Architektur}, language = {en} } @article{ZhuangHuangLiangetal., author = {Zhuang, Xiaoying and Huang, Runqiu and Liang, Chao and Rabczuk, Timon}, title = {A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage}, series = {Mathematical Problems in Engineering}, journal = {Mathematical Problems in Engineering}, doi = {10.1155/2014/179169}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170428-31726}, abstract = {Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES) provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM) modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared.}, subject = {Energiespeicherung}, language = {en} } @article{AmaniSaboorBagherzadehRabczuk, author = {Amani, Jafar and Saboor Bagherzadeh, Amir and Rabczuk, Timon}, title = {Error estimate and adaptive refinement in mixed discrete least squares meshless method}, series = {Mathematical Problems in Engineering}, journal = {Mathematical Problems in Engineering}, doi = {10.1155/2014/721240}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170413-31181}, abstract = {The node moving and multistage node enrichment adaptive refinement procedures are extended in mixed discrete least squares meshless (MDLSM) method for efficient analysis of elasticity problems. In the formulation of MDLSM method, mixed formulation is accepted to avoid second-order differentiation of shape functions and to obtain displacements and stresses simultaneously. In the refinement procedures, a robust error estimator based on the value of the least square residuals functional of the governing differential equations and its boundaries at nodal points is used which is inherently available from the MDLSM formulation and can efficiently identify the zones with higher numerical errors. The results are compared with the refinement procedures in the irreducible formulation of discrete least squares meshless (DLSM) method and show the accuracy and efficiency of the proposed procedures. Also, the comparison of the error norms and convergence rate show the fidelity of the proposed adaptive refinement procedures in the MDLSM method.}, subject = {Elastizit{\"a}t}, language = {en} } @article{NguyenThoiRabczukLamPhatetal., author = {Nguyen-Thoi, T. and Rabczuk, Timon and Lam-Phat, T. and Ho-Huu, V. and Phung-Van, P.}, title = {Free vibration analysis of cracked Mindlin plate using an extended cell-based smoothed discrete shear gap method (XCS-DSG3)}, series = {Theoretical and Applied Fracture Mechanics}, journal = {Theoretical and Applied Fracture Mechanics}, abstract = {Free vibration analysis of cracked Mindlin plate using an extended cell-based smoothed discrete shear gap method (XCS-DSG3)}, subject = {Angewandte Mathematik}, language = {en} } @article{ZhuangHuangRabczuketal., author = {Zhuang, Xiaoying and Huang, Runqiu and Rabczuk, Timon and Liang, C.}, title = {A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage}, series = {Mathematical Problems in Engineering}, journal = {Mathematical Problems in Engineering}, abstract = {A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage}, subject = {Angewandte Mathematik}, language = {en} } @article{AmiriMillanShenetal., author = {Amiri, Fatemeh and Mill{\´a}n, D. and Shen, Y. and Rabczuk, Timon and Arroyo, M.}, title = {Phase-field modeling of fracture in linear thin shells}, series = {Theoretical and Applied Fracture Mechanics}, journal = {Theoretical and Applied Fracture Mechanics}, pages = {102 -- 109}, abstract = {Phase-field modeling of fracture in linear thin shells}, subject = {Angewandte Mathematik}, language = {en} } @article{JiangParkRabczuk, author = {Jiang, Jin-Wu and Park, Harold S. and Rabczuk, Timon}, title = {MoS2 nanoresonators: intrinsically better than graphene?}, series = {Nanoscale}, journal = {Nanoscale}, pages = {3618 -- 3625}, abstract = {MoS2 nanoresonators: intrinsically better than graphene?}, subject = {Angewandte Mathematik}, language = {en} } @article{KoenigKnecht, author = {K{\"o}nig, Reinhard and Knecht, Katja}, title = {Comparing two evolutionary algorithm based methods for layout generation: Dense packing versus subdivision}, series = {Artificial Intelligence for Engineering Design, Analysis and Manufacturing}, journal = {Artificial Intelligence for Engineering Design, Analysis and Manufacturing}, pages = {285 -- 299}, abstract = {We present and compare two evolutionary algorithm based methods for rectangular architectural layout generation: dense packing and subdivision algorithms.We analyze the characteristics of the two methods on the basis of three floor plan sce- narios. Our analyses include the speed with which solutions are generated, the reliability with which optimal solutions can be found, and the number of different solutions that can be found overall. In a following step, we discuss the methods with respect to their different user interaction capabilities. In addition, we show that each method has the capability to generate more complex L-shaped layouts. Finally,we conclude that neither of the methods is superior but that each of them is suitable for use in distinct application scenarios because of its different properties.}, subject = {Architektur}, language = {en} } @article{AreiasPintodaCostaRabczuketal., author = {Areias, Pedro and Pinto da Costa, A. and Rabczuk, Timon and Queiros de Melo, F. J. M. and Dias-da-Costa, D.}, title = {An alternative formulation for quasi-static frictional and cohesive contact problems}, series = {Computational Mechanics}, journal = {Computational Mechanics}, pages = {807 -- 824}, abstract = {An alternative formulation for quasi-static frictional and cohesive contact problems}, subject = {Angewandte Mathematik}, language = {en} } @article{BudarapuGracieYangetal., author = {Budarapu, Pattabhi Ramaiah and Gracie, Robert and Yang, Shih-Wei and Zhuang, Xiaoying and Rabczuk, Timon}, title = {Efficient Coarse Graining in Multiscale Modeling of Fracture}, series = {Theoretical and Applied Fracture Mechanics}, journal = {Theoretical and Applied Fracture Mechanics}, pages = {126 -- 143}, abstract = {Efficient Coarse Graining in Multiscale Modeling of Fracture}, subject = {Angewandte Mathematik}, language = {en} } @article{NguyenXuanNguyenBordasetal., author = {Nguyen-Xuan, Hung and Nguyen, Hiep Vinh and Bordas, St{\´e}phane Pierre Alain and Rabczuk, Timon and Duflot, Marc}, title = {A cell-based smoothed finite element method for three dimensional solid structures}, series = {KSCE Journal of Civil Engineering}, journal = {KSCE Journal of Civil Engineering}, doi = {10.1007/s12205-012-1515-7}, pages = {1230 -- 1242}, abstract = {This paper extends further the strain smoothing technique in finite elements to 8-noded hexahedral elements (CS-FEM-H8). The idea behind the present method is similar to the cell-based smoothed 4-noded quadrilateral finite elements (CS-FEM-Q4). In CSFEM, the smoothing domains are created based on elements, and each element can be further subdivided into 1 or several smoothing cells. It is observed that: 1) The CS-FEM using a single smoothing cell can produce higher stress accuracy, but insufficient rank and poor displacement accuracy; 2) The CS-FEM using several smoothing cells has proper rank, good displacement accuracy, but lower stress accuracy, especially for nearly incompressible and bending dominant problems. We therefore propose 1) an extension of strain smoothing to 8-noded hexahedral elements and 2) an alternative CS-FEM form, which associates the single smoothing cell issue with multi-smoothing cell one via a stabilization technique. Several numerical examples are provided to show the reliability and accuracy of the present formulation.}, subject = {Angewandte Mathematik}, language = {en} } @article{BudarapuGracieBordasetal., author = {Budarapu, Pattabhi Ramaiah and Gracie, Robert and Bordas, St{\´e}phane Pierre Alain and Rabczuk, Timon}, title = {An adaptive multiscale method for quasi-static crack growth}, series = {Computational Mechanics}, journal = {Computational Mechanics}, doi = {10.1007/s00466-013-0952-6}, pages = {1129 -- 1148}, abstract = {This paper proposes an adaptive atomistic- continuum numerical method for quasi-static crack growth. The phantom node method is used to model the crack in the continuum region and a molecular statics model is used near the crack tip. To ensure self-consistency in the bulk, a virtual atom cluster is used to model the material of the coarse scale. The coupling between the coarse scale and fine scale is realized through ghost atoms. The ghost atom positions are interpolated from the coarse scale solution and enforced as boundary conditions on the fine scale. The fine scale region is adaptively enlarged as the crack propagates and the region behind the crack tip is adaptively coarsened. An energy criterion is used to detect the crack tip location. The triangular lattice in the fine scale region corresponds to the lattice structure of the (111) plane of an FCC crystal. The Lennard-Jones potential is used to model the atom-atom interactions. The method is implemented in two dimensions. The results are compared to pure atomistic simulations; they show excellent agreement.}, subject = {Angewandte Mathematik}, language = {en} } @article{BeexKerfridenRabczuketal., author = {Beex, L.A.A. and Kerfriden, Pierre and Rabczuk, Timon and Bordas, St{\´e}phane Pierre Alain}, title = {Quasicontinuum-based multiscale approaches for plate-like beam lattices experiencing in-plane and out-of-plane deformation}, series = {Computer Methods in Applied Mechanics and Engineering}, journal = {Computer Methods in Applied Mechanics and Engineering}, abstract = {Quasicontinuum-based multiscale approaches for plate-like beam lattices experiencing in-plane and out-of-plane deformation}, subject = {Angewandte Mathematik}, language = {en} } @article{NguyenKerfridenBordasetal., author = {Nguyen, V.P. and Kerfriden, Pierre and Bordas, St{\´e}phane Pierre Alain and Rabczuk, Timon}, title = {Isogeometric analysis suitable trivariate NURBS representation of composite panels with a new offset algorithm}, series = {Computer-Aided Design}, journal = {Computer-Aided Design}, abstract = {Isogeometric analysis suitable trivariate NURBS representation of composite panels with a new offset algorithm}, subject = {Angewandte Mathematik}, language = {en} } @article{TalebiSilaniBordasetal., author = {Talebi, Hossein and Silani, Mohammad and Bordas, St{\´e}phane Pierre Alain and Kerfriden, Pierre and Rabczuk, Timon}, title = {A computational library for multiscale modeling of material failure}, series = {Computational Mechanics}, journal = {Computational Mechanics}, abstract = {A computational library for multiscale modeling of material failure}, subject = {Angewandte Mathematik}, language = {en} } @article{IlyaniAkmarLahmerBordasetal., author = {Ilyani Akmar, A.B. and Lahmer, Tom and Bordas, St{\´e}phane Pierre Alain and Beex, L.A.A. and Rabczuk, Timon}, title = {Uncertainty quantification of dry woven fabrics: A sensitivity analysis on material properties}, series = {Composite Structures}, journal = {Composite Structures}, doi = {10.1016/j.compstruct.2014.04.014}, pages = {1 -- 17}, abstract = {Uncertainty quantification of dry woven fabrics: A sensitivity analysis on material properties}, subject = {Angewandte Mathematik}, language = {en} } @article{NanthakumarLahmerRabczuk, author = {Nanthakumar, S.S. and Lahmer, Tom and Rabczuk, Timon}, title = {Detection of multiple flaws in piezoelectric structures using XFEM and level sets}, series = {Computer Methods in Applied Mechanics and Engineering}, journal = {Computer Methods in Applied Mechanics and Engineering}, pages = {98 -- 112}, abstract = {Detection of multiple flaws in piezoelectric structures using XFEM and level sets}, subject = {Angewandte Mathematik}, language = {en} } @article{AreiasRabczukCamanho, author = {Areias, Pedro and Rabczuk, Timon and Camanho, P.P.}, title = {Finite strain fracture of 2D problems with injected anisotropic softening elements}, series = {Theoretical and Applied Fracture Mechanics}, journal = {Theoretical and Applied Fracture Mechanics}, abstract = {Finite strain fracture of 2D problems with injected anisotropic softening elements}, subject = {Angewandte Mathematik}, language = {en} } @article{VuBacLahmerKeiteletal., author = {Vu-Bac, N. and Lahmer, Tom and Keitel, Holger and Zhao, Jun-Hua and Zhuang, Xiaoying and Rabczuk, Timon}, title = {Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations}, series = {Mechanics of Materials}, journal = {Mechanics of Materials}, pages = {70 -- 84}, abstract = {Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations}, subject = {Angewandte Mathematik}, language = {en} } @article{JiaAnitescuGhorashietal., author = {Jia, Yue and Anitescu, Cosmin and Ghorashi, Seyed Shahram and Rabczuk, Timon and Dias-da-Costa, D.}, title = {Extended Isogeometric Analysis for Material Interface Problems}, series = {Journal of Applied Mathematics}, journal = {Journal of Applied Mathematics}, abstract = {Extended Isogeometric Analysis for Material Interface Problems}, subject = {Angewandte Mathematik}, language = {en} } @article{ChenSchwingKarlovšeketal., author = {Chen, Zhen and Schwing, Moritz and Karlovšek, Jurij and Wagner, Norman and Scheuermann, Alexander}, title = {Broadband Dielectric Measurement Methods for Soft Geomaterials: Coaxial Transmission Line Cell and Open-Ended Coaxial Probe}, series = {International Journal of Engineering and Technology}, volume = {2014}, journal = {International Journal of Engineering and Technology}, number = {volume 6, number 5}, doi = {10.7763/IJET.2014.V6.728}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210408-43984}, pages = {373 -- 380}, abstract = {Broadband dielectric measurement methods based on vector network analyzer coupled with coaxial transmission line cell (CC) and open-ended coaxial probe (OC) are simply reviewed, by which the dielectric behaviors in the frequency range of 1 MHz to 3 GHz of two practical geomaterials are investigated. Kaolin after modified compaction with different water contents is measured by using CC. The results are consistent with previous study on standardized compacted kaolin and suggest that the dielectric properties at frequencies below 100 MHz are not only a function of water content but also functions of other soil state parameters including dry density. The hydration process of a commercial grout is monitored in real time by using OC. It is found that the time dependent dielectric properties can accurately reveal the different stages of the hydration process. These measurement results demonstrate the practicability of the introduced methods in determining dielectric properties of soft geomaterials.}, subject = {Impedanzspektroskopie}, language = {en} } @article{VoelskeGollubHagenetal., author = {V{\"o}lske, Michael and Gollub, Tim and Hagen, Matthias and Stein, Benno}, title = {A keyquery-based classification system for CORE}, series = {D-Lib Magazine}, journal = {D-Lib Magazine}, doi = {10.1045/november14-voelske}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170426-31662}, abstract = {We apply keyquery-based taxonomy composition to compute a classification system for the CORE dataset, a shared crawl of about 850,000 scientific papers. Keyquery-based taxonomy composition can be understood as a two-phase hierarchical document clustering technique that utilizes search queries as cluster labels: In a first phase, the document collection is indexed by a reference search engine, and the documents are tagged with the search queries they are relevant—for their so-called keyqueries. In a second phase, a hierarchical clustering is formed from the keyqueries within an iterative process. We use the explicit topic model ESA as document retrieval model in order to index the CORE dataset in the reference search engine. Under the ESA retrieval model, documents are represented as vectors of similarities to Wikipedia articles; a methodology proven to be advantageous for text categorization tasks. Our paper presents the generated taxonomy and reports on quantitative properties such as document coverage and processing requirements.}, subject = {Massendaten}, language = {en} } @article{LuuMartinezRodrigoZabeletal., author = {Luu, M. and Martinez-Rodrigo, M.D. and Zabel, Volkmar and K{\"o}nke, Carsten}, title = {H∞ optimization of fluid viscous dampers for reducing vibrations of high-speed railway bridges}, series = {Journal of Sound and Vibration}, journal = {Journal of Sound and Vibration}, pages = {2421 -- 2442}, abstract = {H∞ optimization of fluid viscous dampers for reducing vibrations of high-speed railway bridges}, subject = {Angewandte Mathematik}, language = {en} }