TY - JOUR A1 - Zhuang, Xiaoying A1 - Huang, Runqiu A1 - Rabczuk, Timon A1 - Liang, C. T1 - A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage JF - Mathematical Problems in Engineering N2 - A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Zhuang, Xiaoying A1 - Huang, Runqiu A1 - Liang, Chao A1 - Rabczuk, Timon T1 - A coupled thermo-hydro-mechanical model of jointed hard rock for compressed air energy storage JF - Mathematical Problems in Engineering N2 - 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. KW - Energiespeicherung KW - Druckluft KW - Kaverne KW - Modellierung Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170428-31726 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Wei, Ning A1 - Fan, Z. A1 - Jiang, Jin-Wu A1 - Rabczuk, Timon T1 - Mechanical properties of three types of carbon allotropes JF - Nanotechnology N2 - Mechanical properties of three types of carbon allotropes KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Wang, L. A1 - Jiang, Jin-Wu A1 - Wang, Z. A1 - Guo, Wanlin A1 - Rabczuk, Timon T1 - A comparative study of two molecular mechanics models based on harmonic potentials JF - Journal of Applied Physics N2 - A comparative study of two molecular mechanics models based on harmonic potentials KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Lu, Lixin A1 - Zhang, Zhiliang A1 - Guo, Wanlin A1 - Rabczuk, Timon T1 - Continuum modeling of the cohesive energy for the interfaces between _lms, spheres, coats and substrates JF - Computational Materials Science N2 - Continuum modeling of the cohesive energy for the interfaces between _lms, spheres, coats and substrates KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 432 EP - 438 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Lu, Lixin A1 - Rabczuk, Timon T1 - Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines JF - The Journal of Chemical Physics N2 - Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1063/1.4878115 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Kou, Liangzhi A1 - Jiang, Jin-Wu A1 - Rabczuk, Timon T1 - Tension-induced phase transition of single-layer molybdenum disulphide (MoS2) at low temperatures JF - Nanotechnology N2 - Tension-induced phase transition of single-layer molybdenum disulphide (MoS2) at low temperatures KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1088/0957-4484/25/29/295701 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Jiang, Jin-Wu A1 - Jia, Yue A1 - Guo, Wanlin A1 - Rabczuk, Timon T1 - A theoretical analysis of cohesive energy between carbon nanotubes, graphene and substrates JF - Carbon N2 - 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. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.carbon.2013.01.041 SP - 108 EP - 119 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Jia, Yue A1 - Wei, Ning A1 - Rabczuk, Timon T1 - Binding energy and mechanical stability of two parallel and crossing carbon nanotubes JF - Journal of Applied Mechanics N2 - Binding energy and mechanical stability of two parallel and crossing carbon nanotubes KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 ER - TY - JOUR A1 - Zhao, Jun-Hua A1 - Guo, Wanlin A1 - Rabczuk, Timon T1 - An analytical molecular mechanics model for the elastic properties of crystalline polyethylene JF - Journal of Applied Physics N2 - We present an analytical model to relate the elastic properties of crystalline polyethylene based on a molecular mechanics approach. Along the polymer chains direction, the united-atom (UA) CH2-CH2 bond stretching, angle bending potentials are replaced with equivalent Euler-Bernoulli beams. Between any two polymer chains, the explicit formulae are derived for the van der Waals interaction represented by the linear springs of different stiffness. Then, the nine independent elastic constants are evaluated systematically using the formulae. The analytical model is finally validated by present united-atom molecular dynamics (MD) simulations and against available all-atom molecular dynamics results in the literature. The established analytical model provides an efficient route for mechanical characterization of crystalline polymers and related materials. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2012 U6 - http://dx.doi.org/10.1063/1.4745035 ER - TY - JOUR A1 - Zhao, Jiyun A1 - Lu, Lixin A1 - Rabczuk, Timon T1 - The tensile and shear failure behavior dependence on chain length and temperature in amorphous polymers JF - Computational Materials Science N2 - The tensile and shear failure behavior dependence on chain length and temperature in amorphous polymers KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 567 EP - 572 ER - TY - JOUR A1 - Zhao, Jiyun A1 - Jiang, Jin-Wu A1 - Wang, L. A1 - Guo, Wanlin A1 - Rabczuk, Timon T1 - Coarse-grained potentials of single-walled carbon nanotubes JF - Journal of the Mechanics and Physics of Solids N2 - Coarse-grained potentials of single-walled carbon nanotubes KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Zhang, Yongzheng A1 - Ren, Huilong T1 - Implicit implementation of the nonlocal operator method: an open source code JF - Engineering with computers N2 - In this paper, we present an open-source code for the first-order and higher-order nonlocal operator method (NOM) including a detailed description of the implementation. The NOM is based on so-called support, dual-support, nonlocal operators, and an operate energy functional ensuring stability. The nonlocal operator is a generalization of the conventional differential operators. Combined with the method of weighed residuals and variational principles, NOM establishes the residual and tangent stiffness matrix of operate energy functional through some simple matrix without the need of shape functions as in other classical computational methods such as FEM. NOM only requires the definition of the energy drastically simplifying its implementation. The implementation in this paper is focused on linear elastic solids for sake of conciseness through the NOM can handle more complex nonlinear problems. The NOM can be very flexible and efficient to solve partial differential equations (PDEs), it’s also quite easy for readers to use the NOM and extend it to solve other complicated physical phenomena described by one or a set of PDEs. Finally, we present some classical benchmark problems including the classical cantilever beam and plate-with-a-hole problem, and we also make an extension of this method to solve complicated problems including phase-field fracture modeling and gradient elasticity material. KW - Strukturmechanik KW - Nonlocal operator method KW - Operator energy functional KW - Implicit KW - Dual-support KW - Variational principle KW - Taylor series expansion KW - Stiffness matrix Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220216-45930 UR - https://link.springer.com/article/10.1007/s00366-021-01537-x VL - 2022 SP - 1 EP - 35 PB - Springer CY - London ER - TY - JOUR A1 - Zhang, Yongzheng T1 - Nonlocal dynamic Kirchhoff plate formulation based on nonlocal operator method JF - Engineering with Computers N2 - 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. KW - Angewandte Mathematik KW - nonlocal operator method KW - nonlocal Hessian operator KW - operator energy functional KW - dual-support KW - variational principle Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220209-45849 UR - https://link.springer.com/article/10.1007/s00366-021-01587-1 VL - 2022 SP - 1 EP - 35 PB - Springer CY - London ER - TY - JOUR A1 - Zhang, Yancheng A1 - Zhuang, Xiaoying A1 - Muthu, Jacob A1 - Mabrouki, Tarek A1 - Fontaine, Michaël A1 - Gong, Yadong A1 - Rabczuk, Timon T1 - Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation JF - Composites Part B Engineering N2 - Load transfer of graphene/carbon nanotube/polyethylene hybrid nanocomposite by molecular dynamics simulation KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 27 EP - 33 ER - TY - JOUR A1 - Zhang, Yancheng A1 - Zhao, Jun-Hua A1 - Jia, Yue A1 - Mabrouki, Tarek A1 - Gong, Yadong A1 - Wei, Ning A1 - Rabczuk, Timon T1 - An analytical solution on the interface debonding for large diameter carbon nanotube-reinforced composite with functionally graded variation interphase JF - Composite Structures N2 - An analytical solution on the interface debonding for large diameter carbon nanotube-reinforced composite with functionally graded variation interphase KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 SP - 261 EP - 269 ER - TY - JOUR A1 - Zhang, Yancheng A1 - Zhao, Jiyun A1 - Wei, Ning A1 - Jiang, Jin-Wu A1 - Rabczuk, Timon T1 - Effects of the dispersion of polymer wrapped two neighbouring single walled carbon nanotubes (SWNTs) on nanoengineering load transfer JF - Composites Part B: Engineering N2 - Effects of the dispersion of polymer wrapped two neighbouring single walled carbon nanotubes (SWNTs) on nanoengineering load transfer KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 SP - 1714 EP - 1721 ER - TY - JOUR A1 - Zhang, Yancheng A1 - Wei, Ning A1 - Zhao, Jun-Hua A1 - Gong, Yadong A1 - Rabczuk, Timon T1 - Quasi-analytical solution for the stable system of the multi-layer folded graphene wrinkles JF - Journal of Applied Physics N2 - Quasi-analytical solution for the stable system of the multi-layer folded graphene wrinkles KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Zhang, Chao A1 - Wang, Cuixia A1 - Lahmer, Tom A1 - He, Pengfei A1 - Rabczuk, Timon T1 - A dynamic XFEM formulation for crack identification JF - International Journal of Mechanics and Materials in Design N2 - A dynamic XFEM formulation for crack identification KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 SP - 427 EP - 448 ER - TY - JOUR A1 - Zhang, Chao A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Rabczuk, Timon T1 - Multiple cracks identification for piezoelectric structures JF - International Journal of Fracture N2 - Multiple cracks identification for piezoelectric structures KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2017 SP - 1 EP - 19 ER - TY - JOUR A1 - Zhang, Chao A1 - Hao, Xiao-Li A1 - Wang, Cuixia A1 - Wei, Ning A1 - Rabczuk, Timon T1 - Thermal conductivity of graphene nanoribbons under shear deformation: A molecular dynamics simulation JF - Scientific Reports N2 - Tensile strain and compress strain can greatly affect the thermal conductivity of graphene nanoribbons (GNRs). However, the effect of GNRs under shear strain, which is also one of the main strain effect, has not been studied systematically yet. In this work, we employ reverse nonequilibrium molecular dynamics (RNEMD) to the systematical study of the thermal conductivity of GNRs (with model size of 4 nm × 15 nm) under the shear strain. Our studies show that the thermal conductivity of GNRs is not sensitive to the shear strain, and the thermal conductivity decreases only 12–16% before the pristine structure is broken. Furthermore, the phonon frequency and the change of the micro-structure of GNRs, such as band angel and bond length, are analyzed to explore the tendency of thermal conductivity. The results show that the main influence of shear strain is on the in-plane phonon density of states (PDOS), whose G band (higher frequency peaks) moved to the low frequency, thus the thermal conductivity is decreased. The unique thermal properties of GNRs under shear strains suggest their great potentials for graphene nanodevices and great potentials in the thermal managements and thermoelectric applications. KW - Wärmeleitfähigkeit KW - Graphen KW - Schubspannung Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170428-31718 ER - TY - JOUR A1 - Zerbst, U. A1 - Vormwald, Michael A1 - Andersch, C. A1 - Mädler, K. A1 - Pfuff, M. T1 - The development of a damage tolerance concept for railway components and its demonstration for a railway axle JF - Engineering Fracture Mechanics N2 - The development of a damage tolerance concept for railway components and its demonstration for a railway axle KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2005 SP - 209 EP - 239 ER - TY - JOUR A1 - Zabel, Volkmar A1 - Brehm, Maik T1 - Das dynamische Verhalten von Eisenbahnbrücken mit kurzer Spannweite - numerische und experimentelle Untersuchungen JF - Bauingenieur, D-A-CH-Mitteilungsblatt N2 - Das dynamische Verhalten von Eisenbahnbrücken mit kurzer Spannweite - numerische und experimentelle Untersuchungen KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2008 ER - TY - JOUR A1 - Zabel, Volkmar T1 - An application of discrete wavelet analysis and connection coefficients to parametric system identification JF - Structural Health Monitoring N2 - An application of discrete wavelet analysis and connection coefficients to parametric system identification KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2005 SP - 5 EP - 18 ER - TY - JOUR A1 - Yang, Shih-Wei A1 - Budarapu, Pattabhi Ramaiah A1 - Mahapatra, D.R. A1 - Bordas, Stéphane Pierre Alain A1 - Zi, Goangseup A1 - Rabczuk, Timon T1 - A Meshless Adaptive Multiscale Method for Fracture JF - Computational Materials Science N2 - A Meshless Adaptive Multiscale Method for Fracture KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 382 EP - 395 ER - TY - JOUR A1 - Xu, G. A1 - Mourrain, B. A1 - Galligo, A. A1 - Rabczuk, Timon T1 - High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods JF - Computational Mechanics N2 - High-quality construction of analysis-suitable trivariate NURBS solids by reparameterization methods KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Vu-Bac, N. A1 - Silani, Mohammad A1 - Lahmer, Tom A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - A unified framework for stochastic predictions of Young's modulus of clay/epoxy nanocomposites (PCNs) JF - Computational Materials Science N2 - A unified framework for stochastic predictions of Young's modulus of clay/epoxy nanocomposites (PCNs) KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2015 SP - 520 EP - 535 ER - TY - JOUR A1 - Vu-Bac, N. A1 - Rafiee, Roham A1 - Zhuang, Xiaoying A1 - Lahmer, Tom A1 - Rabczuk, Timon T1 - Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters JF - Composites Part B: Engineering N2 - Uncertainty quantification for multiscale modeling of polymer nanocomposites with correlated parameters KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2015 SP - 446 EP - 464 ER - TY - JOUR A1 - Vu-Bac, N. A1 - Nguyen-Xuan, Hung A1 - Chen, Lei A1 - Lee, C.K. A1 - Zi, Goangseup A1 - Zhuang, Xiaoying A1 - Liu, G.R. A1 - Rabczuk, Timon T1 - A phantom-node method with edge-based strain smoothing for linear elastic fracture mechanics JF - Journal of Applied Mathematics N2 - This paper presents a novel numerical procedure based on the combination of an edge-based smoothed finite element (ES-FEM) with a phantom-node method for 2D linear elastic fracture mechanics. In the standard phantom-node method, the cracks are formulated by adding phantom nodes, and the cracked element is replaced by two new superimposed elements. This approach is quite simple to implement into existing explicit finite element programs. The shape functions associated with discontinuous elements are similar to those of the standard finite elements, which leads to certain simplification with implementing in the existing codes. The phantom-node method allows modeling discontinuities at an arbitrary location in the mesh. The ES-FEM model owns a close-to-exact stiffness that is much softer than lower-order finite element methods (FEM). Taking advantage of both the ES-FEM and the phantom-node method, we introduce an edge-based strain smoothing technique for the phantom-node method. Numerical results show that the proposed method achieves high accuracy compared with the extended finite element method (XFEM) and other reference solutions. KW - Finite-Elemente-Methode KW - Steifigkeit KW - Bruchmechanik KW - Riss Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170426-31676 ER - TY - JOUR A1 - Vu-Bac, N. A1 - Lahmer, Tom A1 - Zhuang, Xiaoying A1 - Nguyen-Thoi, T. A1 - Rabczuk, Timon T1 - A software framework for probabilistic sensitivity analysis for computationally expensive models JF - Advances in Engineering Software N2 - A software framework for probabilistic sensitivity analysis for computationally expensive models KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 SP - 19 EP - 31 ER - TY - JOUR A1 - Vu-Bac, N. A1 - Lahmer, Tom A1 - Zhang, Yancheng A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs) JF - Composites Part B Engineering N2 - Stochastic predictions of interfacial characteristic of polymeric nanocomposites (PNCs) KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2014 SP - 80 EP - 95 ER - TY - JOUR A1 - Vu-Bac, N. A1 - Lahmer, Tom A1 - Keitel, Holger A1 - Zhao, Jun-Hua A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations JF - Mechanics of Materials N2 - Stochastic predictions of bulk properties of amorphous polyethylene based on molecular dynamics simulations KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2014 SP - 70 EP - 84 ER - TY - JOUR A1 - Valizadeh, Navid A1 - Natarajan, S. A1 - Gonzalez-Estrada, O.A. A1 - Rabczuk, Timon A1 - Tinh Quoc, Bui A1 - Bordas, Stéphane Pierre Alain T1 - NURBS-based finite element analysis of functionally graded plates: static bending, vibration, buckling and flutter JF - Composite Structures N2 - NURBS-based finite element analysis of functionally graded plates: static bending, vibration, buckling and flutter KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 SP - 309 EP - 326 ER - TY - JOUR A1 - Unger, Jörg F. A1 - Teughels, A. A1 - De Roeck, G. T1 - Damage detection of a prestressed concrete beam using modal strains JF - Journal of Structural Engineering N2 - Damage detection of a prestressed concrete beam using modal strains KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2005 SP - 1456 EP - 1463 ER - TY - JOUR A1 - Unger, Jörg F. A1 - Teughels, A. A1 - De Roeck, G. T1 - System identification and damage detection of a prestressed concrete beam JF - Journal of Structural Engineering N2 - System identification and damage detection of a prestressed concrete beam KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2006 SP - 1691 EP - 1698 ER - TY - JOUR A1 - Unger, Jörg F. A1 - Könke, Carsten T1 - Coupling of scales in a multiscale simulation using neural networks JF - Computers & Structures N2 - Coupling of scales in a multiscale simulation using neural networks KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2008 ER - TY - JOUR A1 - Unger, Jörg F. A1 - Eckardt, Stefan A1 - Könke, Carsten T1 - Modelling of cohesive crack growth in concrete structures with the extended finite element method JF - Computer Methods in Applied Mechanics and Engineering N2 - Modelling of cohesive crack growth in concrete structures with the extended finite element method KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2007 SP - 4087 EP - 4100 ER - TY - JOUR A1 - Thumser, Rayk A1 - Bergmann, Joachim W. A1 - Vormwald, Michael T1 - Residual stress fields and fatigue analysis of autofrettaged parts JF - International Journal of Pressure Vessels and Piping N2 - Residual stress fields and fatigue analysis of autofrettaged parts KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2002 SP - 113 EP - 117 ER - TY - JOUR A1 - Thai, Chien H. A1 - Nguyen-Xuan, Hung A1 - Nguyen-Thanh, Nhon A1 - Le, T.H. A1 - Nguyen-Thoi, T. A1 - Rabczuk, Timon T1 - Static, free vibration and buckling analysis of laminated composite Reissner-Mindlin plates using NURBS-based isogeometric approach JF - International Journal for Numerical Methods in Engineering N2 - This paper presents a novel numerical procedure based on the framework of isogeometric analysis for static, free vibration, and buckling analysis of laminated composite plates using the first-order shear deformation theory. The isogeometric approach utilizes non-uniform rational B-splines to implement for the quadratic, cubic, and quartic elements. Shear locking problem still exists in the stiffness formulation, and hence, it can be significantly alleviated by a stabilization technique. Several numerical examples are presented to show the performance of the method, and the results obtained are compared with other available ones. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2012 U6 - http://dx.doi.org/10.1002/nme.4282 SP - 571 EP - 603 ER - TY - JOUR A1 - Thai, Chien H. A1 - Nguyen-Xuan, Hung A1 - Bordas, Stéphane Pierre Alain A1 - Nguyen-Thanh, Nhon A1 - Rabczuk, Timon T1 - Isogeometric analysis of laminated composite plates using the higher-order shear deformation theory JF - Mechanics of Advanced Materials and Structures N2 - Isogeometric analysis of laminated composite plates using the higher-order shear deformation theory KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 451 EP - 469 ER - TY - JOUR A1 - Thai, Chien H. A1 - Ferreira, A.J.M. A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon A1 - Nguyen-Xuan, Hung T1 - Isogeometric analysis of laminated composite and sandwich plates using a new inverse trigonometric shear deformation theory JF - European Journal of Mechanics N2 - Isogeometric analysis of laminated composite and sandwich plates using a new inverse trigonometric shear deformation theory KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 89 EP - 108 ER - TY - JOUR A1 - Talebi, Hossein A1 - Zi, Goangseup A1 - Silani, Mohammad A1 - Samaniego, Esteban A1 - Rabczuk, Timon T1 - A simple circular cell method for multilevel finite element analysis JF - Journal of Applied Mathematics N2 - A simple multiscale analysis framework for heterogeneous solids based on a computational homogenization technique is presented. The macroscopic strain is linked kinematically to the boundary displacement of a circular or spherical representative volume which contains the microscopic information of the material. The macroscopic stress is obtained from the energy principle between the macroscopic scale and the microscopic scale. This new method is applied to several standard examples to show its accuracy and consistency of the method proposed. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2012 U6 - http://dx.doi.org/10.1155/2012/526846 ER - TY - JOUR A1 - Talebi, Hossein A1 - Zi, Goangseup A1 - Silani, Mohammad A1 - Samaniego, Esteban A1 - Rabczuk, Timon T1 - A simple circular cell method for multilevel finite element analysis JF - Journal of Applied Mathematics N2 - A simple multiscale analysis framework for heterogeneous solids based on a computational homogenization technique is presented. The macroscopic strain is linked kinematically to the boundary displacement of a circular or spherical representative volume which contains the microscopic information of the material. The macroscopic stress is obtained from the energy principle between the macroscopic scale and the microscopic scale. This new method is applied to several standard examples to show its accuracy and consistency of the method proposed. KW - Finite-Elemente-Methode KW - Feststoff Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170426-31639 ER - TY - JOUR A1 - Talebi, Hossein A1 - Silani, Mohammad A1 - Rabczuk, Timon T1 - Concurrent Multiscale Modelling of Three Dimensional Crack and Dislocation Propagation JF - Advances in Engineering Software N2 - Concurrent Multiscale Modelling of Three Dimensional Crack and Dislocation Propagation KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 82 EP - 92 ER - TY - JOUR A1 - Talebi, Hossein A1 - Silani, Mohammad A1 - Bordas, Stéphane Pierre Alain A1 - Kerfriden, Pierre A1 - Rabczuk, Timon T1 - Molecular Dynamics/XFEM Coupling by a Three-Dimensional Extended Bridging Domain with Applications to Dynamic Brittle Fracture JF - International Journal for Multiscale Computational Engineering N2 - Molecular Dynamics/XFEM Coupling by a Three-Dimensional Extended Bridging Domain with Applications to Dynamic Brittle Fracture KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Talebi, Hossein A1 - Silani, Mohammad A1 - Bordas, Stéphane Pierre Alain A1 - Kerfriden, Pierre A1 - Rabczuk, Timon T1 - A computational library for multiscale modeling of material failure JF - Computational Mechanics N2 - A computational library for multiscale modeling of material failure KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Talebi, Hossein A1 - Samaniego, C. A1 - Samaniego, Esteban A1 - Rabczuk, Timon T1 - On the numerical stability and mass-lumping schemes for explicit enriched meshfree methods JF - International Journal for Numerical Methods in Engineering N2 - Meshfree methods (MMs) such as the element free Galerkin (EFG)method have gained popularity because of some advantages over other numerical methods such as the finite element method (FEM). A group of problems that have attracted a great deal of attention from the EFG method community includes the treatment of large deformations and dealing with strong discontinuities such as cracks. One efficient solution to model cracks is adding special enrichment functions to the standard shape functions such as extended FEM, within the FEM context, and the cracking particles method, based on EFG method. It is well known that explicit time integration in dynamic applications is conditionally stable. Furthermore, in enriched methods, the critical time step may tend to very small values leading to computationally expensive simulations. In this work, we study the stability of enriched MMs and propose two mass-lumping strategies. Then we show that the critical time step for enriched MMs based on lumped mass matrices is of the same order as the critical time step of MMs without enrichment. Moreover, we show that, in contrast to extended FEM, even with a consistent mass matrix, the critical time step does not vanish even when the crack directly crosses a node. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2012 U6 - http://dx.doi.org/10.1002/nme.3275 SP - 1009 EP - 1027 ER - TY - JOUR A1 - Stein, Peter A1 - Lahmer, Tom A1 - Bock, Sebastian T1 - Synthese und Analyse von gekoppelten Modellen im konstruktiven Ingenieurbau BT - Sonderdruck‐DFG Graduiertenkolleg JF - Bautechnik N2 - Synthese und Analyse von gekoppelten Modellen im konstruktiven Ingenieurbau KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2011 SP - 8 EP - 11 ER - TY - JOUR A1 - Simpson, R. A1 - Bordas, Stéphane Pierre Alain A1 - Trevelyan, J. A1 - Kerfriden, Pierre A1 - Rabczuk, Timon T1 - An Isogeometric Boundary Element Method for elastostatic analysis JF - Computer Methods in Applied Mechanics and Engineering N2 - The concept of isogeometric analysis, where functions that are used to describe geometry in CAD software are used to approximate the unknown fields in numerical simulations, has received great attention in recent years. The method has the potential to have profound impact on engineering design, since the task of meshing, which in some cases can add significant overhead, has been circumvented. Much of the research effort has been focused on finite element implementations of the isogeometric concept, but at present, little has been seen on the application to the Boundary Element Method. The current paper proposes an Isogeometric Boundary Element Method (BEM), which we term IGABEM, applied to two-dimensional elastostatic problems using Non-Uniform Rational B-Splines (NURBS). We find it is a natural fit with the isogeometric concept since both the NURBS approximation and BEM deal with quantities entirely on the boundary. The method is verified against analytical solutions where it is seen that superior accuracies are achieved over a conventional quadratic isoparametric BEM implementation. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.cma.2011.08.008 ER - TY - JOUR A1 - Silani, Mohammad A1 - Ziaei-Rad, S. A1 - Talebi, Hossein A1 - Rabczuk, Timon T1 - A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites JF - Theoretical and Applied Fracture Mechanics N2 - A Semi-Concurrent Multiscale Approach for Modeling Damage in Nanocomposites KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Silani, Mohammad A1 - Talebi, Hossein A1 - Ziaei-Rad, S. A1 - Hamouda, A.M.S. A1 - Zi, Goangseup A1 - Rabczuk, Timon T1 - A three dimensional Extended Arlequin Method for Dynamic Fracture JF - Computational Materials Science N2 - A three dimensional Extended Arlequin Method for Dynamic Fracture KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 425 EP - 431 ER - TY - JOUR A1 - Silani, Mohammad A1 - Talebi, Hossein A1 - Arnold, Daniel A1 - Ziaei-Rad, S. A1 - Rabczuk, Timon T1 - On the coupling of a commercial finite element package with lammps for multiscale modeling of materials JF - Steel Research International N2 - On the coupling of a commercial finite element package with lammps for multiscale modeling of materials KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Shirazi, A. H. N. A1 - Mohebbi, Farzad A1 - Azadi Kakavand, M. R. A1 - He, B. A1 - Rabczuk, Timon T1 - Paraffin Nanocomposites for Heat Management of Lithium-Ion Batteries: A Computational Investigation JF - JOURNAL OF NANOMATERIALS N2 - Lithium-ion (Li-ion) batteries are currently considered as vital components for advances in mobile technologies such as those in communications and transport. Nonetheless, Li-ion batteries suffer from temperature rises which sometimes lead to operational damages or may even cause fire. An appropriate solution to control the temperature changes during the operation of Li-ion batteries is to embed batteries inside a paraffin matrix to absorb and dissipate heat. In the present work, we aimed to investigate the possibility of making paraffin nanocomposites for better heat management of a Li-ion battery pack. To fulfill this aim, heat generation during a battery charging/discharging cycles was simulated using Newman’s well established electrochemical pseudo-2D model. We couple this model to a 3D heat transfer model to predict the temperature evolution during the battery operation. In the later model, we considered different paraffin nanocomposites structures made by the addition of graphene, carbon nanotubes, and fullerene by assuming the same thermal conductivity for all fillers. This way, our results mainly correlate with the geometry of the fillers. Our results assess the degree of enhancement in heat dissipation of Li-ion batteries through the use of paraffin nanocomposites. Our results may be used as a guide for experimental set-ups to improve the heat management of Li-ion batteries. KW - Batterie KW - Wärmeleitfähigkeit Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170411-31141 ER - TY - JOUR A1 - Shamshirband, Shahaboddin A1 - Joloudari, Javad Hassannataj A1 - GhasemiGol, Mohammad A1 - Saadatfar, Hamid A1 - Mosavi, Amir A1 - Nabipour, Narjes T1 - FCS-MBFLEACH: Designing an Energy-Aware Fault Detection System for Mobile Wireless Sensor Networks JF - Mathematics N2 - Wireless sensor networks (WSNs) include large-scale sensor nodes that are densely distributed over a geographical region that is completely randomized for monitoring, identifying, and analyzing physical events. The crucial challenge in wireless sensor networks is the very high dependence of the sensor nodes on limited battery power to exchange information wirelessly as well as the non-rechargeable battery of the wireless sensor nodes, which makes the management and monitoring of these nodes in terms of abnormal changes very difficult. These anomalies appear under faults, including hardware, software, anomalies, and attacks by raiders, all of which affect the comprehensiveness of the data collected by wireless sensor networks. Hence, a crucial contraption should be taken to detect the early faults in the network, despite the limitations of the sensor nodes. Machine learning methods include solutions that can be used to detect the sensor node faults in the network. The purpose of this study is to use several classification methods to compute the fault detection accuracy with different densities under two scenarios in regions of interest such as MB-FLEACH, one-class support vector machine (SVM), fuzzy one-class, or a combination of SVM and FCS-MBFLEACH methods. It should be noted that in the study so far, no super cluster head (SCH) selection has been performed to detect node faults in the network. The simulation outcomes demonstrate that the FCS-MBFLEACH method has the best performance in terms of the accuracy of fault detection, false-positive rate (FPR), average remaining energy, and network lifetime compared to other classification methods. KW - Vernetzung KW - wireless sensor networks KW - machine learning KW - Funktechnik KW - Sensor KW - Maschinelles Lernen KW - Internet of Things KW - OA-Publikationsfonds2019 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200107-40541 UR - https://www.mdpi.com/2227-7390/8/1/28 VL - 2020 IS - Volume 8, Issue 1, article 28 PB - MDPI ER - TY - JOUR A1 - Shamshirband, Shahaboddin A1 - Babanezhad, Meisam A1 - Mosavi, Amir A1 - Nabipour, Narjes A1 - Hajnal, Eva A1 - Nadai, Laszlo A1 - Chau, Kwok-Wing T1 - Prediction of flow characteristics in the bubble column reactor by the artificial pheromone-based communication of biological ants JF - Engineering Applications of Computational Fluid Mechanics N2 - A novel combination of the ant colony optimization algorithm (ACO)and computational fluid dynamics (CFD) data is proposed for modeling the multiphase chemical reactors. The proposed intelligent model presents a probabilistic computational strategy for predicting various levels of three-dimensional bubble column reactor (BCR) flow. The results prove an enhanced communication between ant colony prediction and CFD data in different sections of the BCR. KW - Maschinelles Lernen KW - Machine learning KW - Bubble column reactor KW - ant colony optimization algorithm (ACO) KW - flow pattern KW - computational fluid dynamics (CFD) KW - big data KW - OA-Publikationsfonds2020 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200227-41013 UR - https://www.tandfonline.com/doi/full/10.1080/19942060.2020.1715842 VL - 2020 IS - volume 14, issue 1 SP - 367 EP - 378 PB - Taylor & Francis ER - TY - JOUR A1 - Shabani, Sevda A1 - Samadianfard, Saeed A1 - Sattari, Mohammad Taghi A1 - Mosavi, Amir A1 - Shamshirband, Shahaboddin A1 - Kmet, Tibor A1 - Várkonyi-Kóczy, Annamária R. T1 - Modeling Pan Evaporation Using Gaussian Process Regression K-Nearest Neighbors Random Forest and Support Vector Machines; Comparative Analysis JF - Atmosphere N2 - Evaporation is a very important process; it is one of the most critical factors in agricultural, hydrological, and meteorological studies. Due to the interactions of multiple climatic factors, evaporation is considered as a complex and nonlinear phenomenon to model. Thus, machine learning methods have gained popularity in this realm. In the present study, four machine learning methods of Gaussian Process Regression (GPR), K-Nearest Neighbors (KNN), Random Forest (RF) and Support Vector Regression (SVR) were used to predict the pan evaporation (PE). Meteorological data including PE, temperature (T), relative humidity (RH), wind speed (W), and sunny hours (S) collected from 2011 through 2017. The accuracy of the studied methods was determined using the statistical indices of Root Mean Squared Error (RMSE), correlation coefficient (R) and Mean Absolute Error (MAE). Furthermore, the Taylor charts utilized for evaluating the accuracy of the mentioned models. The results of this study showed that at Gonbad-e Kavus, Gorgan and Bandar Torkman stations, GPR with RMSE of 1.521 mm/day, 1.244 mm/day, and 1.254 mm/day, KNN with RMSE of 1.991 mm/day, 1.775 mm/day, and 1.577 mm/day, RF with RMSE of 1.614 mm/day, 1.337 mm/day, and 1.316 mm/day, and SVR with RMSE of 1.55 mm/day, 1.262 mm/day, and 1.275 mm/day had more appropriate performances in estimating PE values. It was found that GPR for Gonbad-e Kavus Station with input parameters of T, W and S and GPR for Gorgan and Bandar Torkmen stations with input parameters of T, RH, W and S had the most accurate predictions and were proposed for precise estimation of PE. The findings of the current study indicated that the PE values may be accurately estimated with few easily measured meteorological parameters. KW - Maschinelles Lernen KW - Machine learning KW - Deep learning Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200110-40561 UR - https://www.mdpi.com/2073-4433/11/1/66 VL - 2020 IS - Volume 11, Issue 1, 66 ER - TY - JOUR A1 - Schrader, Kai A1 - Könke, Carsten T1 - Distributed computing for the nonlinear analysis of multiphase composites JF - Advances in Engineering Software N2 - Distributed computing for the nonlinear analysis of multiphase composites KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 SP - 20 EP - 32 ER - TY - JOUR A1 - Schrader, Kai A1 - Könke, Carsten T1 - Hybrid computing models for large-scale heterogeneous 3d microstructures JF - International Journal for Multiscale Computational Engineering N2 - Hybrid computing models for large-scale heterogeneous 3d microstructures KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2011 SP - 365 EP - 377 ER - TY - JOUR A1 - Schmidt, Albrecht A1 - Lahmer, Tom T1 - Efficient domain decomposition based reliability analysis for polymorphic uncertain material parameters JF - Proceedings in Applied Mathematics & Mechanics N2 - Realistic uncertainty description incorporating aleatoric and epistemic uncertainties can be described within the framework of polymorphic uncertainty, which is computationally demanding. Utilizing a domain decomposition approach for random field based uncertainty models the proposed level-based sampling method can reduce these computational costs significantly and shows good agreement with a standard sampling technique. While 2-level configurations tend to get unstable with decreasing sampling density 3-level setups show encouraging results for the investigated reliability analysis of a structural unit square. KW - Polymorphie KW - Stoffeigenschaft KW - Stochastik KW - polymorphe Unschärfemodellierung KW - Materialverhalten KW - hybride Werkstoffe Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220112-45563 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/pamm.202100014 VL - 2021 IS - Volume 21, issue 1 SP - 1 EP - 4 PB - Wiley-VHC CY - Weinheim ER - TY - JOUR A1 - Savaidis, G. A1 - Vormwald, Michael T1 - Hot-spot stress evaluation of fatigue in welded structural connections supported by finite element analysis JF - International Journal of Fatigue N2 - Hot-spot stress evaluation of fatigue in welded structural connections supported by finite element analysis KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2000 SP - 85 EP - 91 ER - TY - JOUR A1 - Savaidis, G. A1 - Schliebner, R. A1 - Vormwald, Michael T1 - Lebensdauerermittlung von geschweißten, mehrachsig belasteten Nutzfahrzeugkomponenten - Vergleich von Schwingfestigkeiten aus Rechnung und Versuch bei nichtproportionaler Beanspruchung JF - Materialprüfung N2 - Lebensdauerermittlung von geschweißten, mehrachsig belasteten Nutzfahrzeugkomponenten - Vergleich von Schwingfestigkeiten aus Rechnung und Versuch bei nichtproportionaler Beanspruchung KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2001 SP - 381 EP - 386 ER - TY - JOUR A1 - Savaidis, G. A1 - Savaidis, A. A1 - Schliebner, R. A1 - Vormwald, Michael T1 - Evaluation of fatigue of fillet welded joints in vehicle components under multiaxial service loads JF - European Structural Integrity Society N2 - Evaluation of fatigue of fillet welded joints in vehicle components under multiaxial service loads KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2003 SP - 23 EP - 42 ER - TY - JOUR A1 - Saqlai, Syed Muhammad A1 - Ghani, Anwar A1 - Khan, Imran A1 - Ahmed Khan Ghayyur, Shahbaz A1 - Shamshirband, Shahaboddin A1 - Nabipour, Narjes A1 - Shokri, Manouchehr T1 - Image Analysis Using Human Body Geometry and Size Proportion Science for Action Classification JF - Applied Sciences N2 - Gestures are one of the basic modes of human communication and are usually used to represent different actions. Automatic recognition of these actions forms the basis for solving more complex problems like human behavior analysis, video surveillance, event detection, and sign language recognition, etc. Action recognition from images is a challenging task as the key information like temporal data, object trajectory, and optical flow are not available in still images. While measuring the size of different regions of the human body i.e., step size, arms span, length of the arm, forearm, and hand, etc., provides valuable clues for identification of the human actions. In this article, a framework for classification of the human actions is presented where humans are detected and localized through faster region-convolutional neural networks followed by morphological image processing techniques. Furthermore, geometric features from human blob are extracted and incorporated into the classification rules for the six human actions i.e., standing, walking, single-hand side wave, single-hand top wave, both hands side wave, and both hands top wave. The performance of the proposed technique has been evaluated using precision, recall, omission error, and commission error. The proposed technique has been comparatively analyzed in terms of overall accuracy with existing approaches showing that it performs well in contrast to its counterparts. KW - Bildanalyse KW - Mensch KW - Größenverhältnis KW - Geometrie KW - Körper KW - action recognition KW - rule based classification KW - human body proportions KW - human blob KW - OA-Publikationsfonds2020 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200904-42322 UR - https://www.mdpi.com/2076-3417/10/16/5453 VL - 2020 IS - volume 10, issue 16, article 5453 PB - MDPI CY - Basel ER - TY - JOUR A1 - Sadeghzadeh, Milad A1 - Maddah, Heydar A1 - Ahmadi, Mohammad Hossein A1 - Khadang, Amirhosein A1 - Ghazvini, Mahyar A1 - Mosavi, Amir Hosein A1 - Nabipour, Narjes T1 - Prediction of Thermo-Physical Properties of TiO2-Al2O3/Water Nanoparticles by Using Artificial Neural Network JF - Nanomaterials N2 - In this paper, an artificial neural network is implemented for the sake of predicting the thermal conductivity ratio of TiO2-Al2O3/water nanofluid. TiO2-Al2O3/water in the role of an innovative type of nanofluid was synthesized by the sol–gel method. The results indicated that 1.5 vol.% of nanofluids enhanced the thermal conductivity by up to 25%. It was shown that the heat transfer coefficient was linearly augmented with increasing nanoparticle concentration, but its variation with temperature was nonlinear. It should be noted that the increase in concentration may cause the particles to agglomerate, and then the thermal conductivity is reduced. The increase in temperature also increases the thermal conductivity, due to an increase in the Brownian motion and collision of particles. In this research, for the sake of predicting the thermal conductivity of TiO2-Al2O3/water nanofluid based on volumetric concentration and temperature functions, an artificial neural network is implemented. In this way, for predicting thermal conductivity, SOM (self-organizing map) and BP-LM (Back Propagation-Levenberq-Marquardt) algorithms were used. Based on the results obtained, these algorithms can be considered as an exceptional tool for predicting thermal conductivity. Additionally, the correlation coefficient values were equal to 0.938 and 0.98 when implementing the SOM and BP-LM algorithms, respectively, which is highly acceptable. View Full-Text KW - Wärmeleitfähigkeit KW - Fluid KW - Neuronales Netz KW - Thermal conductivity KW - Nanofluid KW - Artificial neural network Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200421-41308 UR - https://www.mdpi.com/2079-4991/10/4/697 VL - 2020 IS - Volume 10, Issue 4, 697 PB - MDPI CY - Basel ER - TY - JOUR A1 - Saadatfar, Hamid A1 - Khosravi, Samiyeh A1 - Hassannataj Joloudari, Javad A1 - Mosavi, Amir A1 - Shamshirband, Shahaboddin T1 - A New K-Nearest Neighbors Classifier for Big Data Based on Efficient Data Pruning JF - Mathematics N2 - The K-nearest neighbors (KNN) machine learning algorithm is a well-known non-parametric classification method. However, like other traditional data mining methods, applying it on big data comes with computational challenges. Indeed, KNN determines the class of a new sample based on the class of its nearest neighbors; however, identifying the neighbors in a large amount of data imposes a large computational cost so that it is no longer applicable by a single computing machine. One of the proposed techniques to make classification methods applicable on large datasets is pruning. LC-KNN is an improved KNN method which first clusters the data into some smaller partitions using the K-means clustering method; and then applies the KNN for each new sample on the partition which its center is the nearest one. However, because the clusters have different shapes and densities, selection of the appropriate cluster is a challenge. In this paper, an approach has been proposed to improve the pruning phase of the LC-KNN method by taking into account these factors. The proposed approach helps to choose a more appropriate cluster of data for looking for the neighbors, thus, increasing the classification accuracy. The performance of the proposed approach is evaluated on different real datasets. The experimental results show the effectiveness of the proposed approach and its higher classification accuracy and lower time cost in comparison to other recent relevant methods. KW - Maschinelles Lernen KW - Machine learning KW - K-nearest neighbors KW - KNN KW - classifier KW - big data KW - clustering KW - cluster shape KW - cluster density KW - classification KW - reinforcement learning KW - data science KW - computation KW - artificial intelligence KW - OA-Publikationsfonds2020 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200225-40996 UR - https://www.mdpi.com/2227-7390/8/2/286 VL - 2020 IS - volume 8, issue 2, article 286 PB - MDPI ER - TY - JOUR A1 - Ren, Huilong A1 - Zhuang, Xiaoying A1 - Oterkus, Erkan A1 - Zhu, Hehua A1 - Rabczuk, Timon T1 - Nonlocal strong forms of thin plate, gradient elasticity, magneto-electro-elasticity and phase-field fracture by nonlocal operator method JF - Engineering with Computers N2 - The derivation of nonlocal strong forms for many physical problems remains cumbersome in traditional methods. In this paper, we apply the variational principle/weighted residual method based on nonlocal operator method for the derivation of nonlocal forms for elasticity, thin plate, gradient elasticity, electro-magneto-elasticity and phase-field fracture method. The nonlocal governing equations are expressed as an integral form on support and dual-support. The first example shows that the nonlocal elasticity has the same form as dual-horizon non-ordinary state-based peridynamics. The derivation is simple and general and it can convert efficiently many local physical models into their corresponding nonlocal forms. In addition, a criterion based on the instability of the nonlocal gradient is proposed for the fracture modelling in linear elasticity. Several numerical examples are presented to validate nonlocal elasticity and the nonlocal thin plate. KW - Bruchmechanik KW - Elastizität KW - Peridynamik KW - energy form KW - weak form KW - peridynamics KW - variational principle KW - explicit time integration Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20211207-45388 UR - https://link.springer.com/article/10.1007/s00366-021-01502-8 VL - 2021 SP - 1 EP - 22 ER - TY - JOUR A1 - Rafiee, Roham A1 - Rabczuk, Timon A1 - Milani, Abbas S. A1 - Tserpes, Konstantinos I. T1 - Advances in Characterization and Modeling of Nanoreinforced Composites JF - JOURNAL OF NANOMATERIALS N2 - This special issue deals with a range of recently developed characterization and modeling techniques employed to better understand and predict the response of nanoreinforced composites at different scales. KW - Physikalische Eigenschaft KW - Werkstoff KW - nanoreinforced composites Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170411-31134 ER - TY - JOUR A1 - Rabizadeh, Ehsan A1 - Saboor Bagherzadeh, Amir A1 - Rabczuk, Timon T1 - Application of goal-oriented error estimation and adaptive mesh refinement on thermo-mechanical multifield problems JF - Computational Materials Science N2 - Application of goal-oriented error estimation and adaptive mesh re_nement on thermo-mechanical multi_eld problems KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 27 EP - 44 ER - TY - JOUR A1 - Rabczuk, Timon A1 - Guo, Hongwei A1 - Zhuang, Xiaoying A1 - Chen, Pengwan A1 - Alajlan, Naif T1 - Stochastic deep collocation method based on neural architecture search and transfer learning for heterogeneous porous media JF - Engineering with Computers N2 - We present a stochastic deep collocation method (DCM) based on neural architecture search (NAS) and transfer learning for heterogeneous porous media. We first carry out a sensitivity analysis to determine the key hyper-parameters of the network to reduce the search space and subsequently employ hyper-parameter optimization to finally obtain the parameter values. The presented NAS based DCM also saves the weights and biases of the most favorable architectures, which is then used in the fine-tuning process. We also employ transfer learning techniques to drastically reduce the computational cost. The presented DCM is then applied to the stochastic analysis of heterogeneous porous material. Therefore, a three dimensional stochastic flow model is built providing a benchmark to the simulation of groundwater flow in highly heterogeneous aquifers. The performance of the presented NAS based DCM is verified in different dimensions using the method of manufactured solutions. We show that it significantly outperforms finite difference methods in both accuracy and computational cost. KW - Maschinelles Lernen KW - Neuronales Lernen KW - Fehlerabschätzung KW - deep learning KW - neural architecture search KW - randomized spectral representation Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20220209-45835 UR - https://link.springer.com/article/10.1007/s00366-021-01586-2 VL - 2022 SP - 1 EP - 26 PB - Springer CY - London ER - TY - JOUR A1 - Phan-Dao, H. A1 - Nguyen-Xuan, Hung A1 - Thai-Hoang, C. A1 - Nguyen-Thoi, T. A1 - Rabczuk, Timon T1 - An edge-based smoothed finite element method for analysis of laminated composite plates JF - International Journal of Computational Methods N2 - An edge-based smoothed finite element method for analysis of laminated composite plates KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Ouaer, Hocine A1 - Hosseini, Amir Hossein A1 - Amar, Menad Nait A1 - Ben Seghier, Mohamed El Amine A1 - Ghriga, Mohammed Abdelfetah A1 - Nabipour, Narjes A1 - Andersen, Pål Østebø A1 - Mosavi, Amir A1 - Shamshirband, Shahaboddin T1 - Rigorous Connectionist Models to Predict Carbon Dioxide Solubility in Various Ionic Liquids JF - Applied Sciences N2 - Estimating the solubility of carbon dioxide in ionic liquids, using reliable models, is of paramount importance from both environmental and economic points of view. In this regard, the current research aims at evaluating the performance of two data-driven techniques, namely multilayer perceptron (MLP) and gene expression programming (GEP), for predicting the solubility of carbon dioxide (CO2) in ionic liquids (ILs) as the function of pressure, temperature, and four thermodynamical parameters of the ionic liquid. To develop the above techniques, 744 experimental data points derived from the literature including 13 ILs were used (80% of the points for training and 20% for validation). Two backpropagation-based methods, namely Levenberg–Marquardt (LM) and Bayesian Regularization (BR), were applied to optimize the MLP algorithm. Various statistical and graphical assessments were applied to check the credibility of the developed techniques. The results were then compared with those calculated using Peng–Robinson (PR) or Soave–Redlich–Kwong (SRK) equations of state (EoS). The highest coefficient of determination (R2 = 0.9965) and the lowest root mean square error (RMSE = 0.0116) were recorded for the MLP-LMA model on the full dataset (with a negligible difference to the MLP-BR model). The comparison of results from this model with the vastly applied thermodynamic equation of state models revealed slightly better performance, but the EoS approaches also performed well with R2 from 0.984 up to 0.996. Lastly, the newly established correlation based on the GEP model exhibited very satisfactory results with overall values of R2 = 0.9896 and RMSE = 0.0201. KW - Maschinelles Lernen KW - Machine learning KW - OA-Publikationsfonds2020 Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200107-40558 UR - https://www.mdpi.com/2076-3417/10/1/304 VL - 2020 IS - Volume 10, Issue 1, 304 PB - MDPI ER - TY - JOUR A1 - Noori, Hamidreza A1 - Mortazavi, Bohayra A1 - Keshtkari, Leila A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - Nanopore creation in MoS2 and graphene monolayers by nanoparticles impact: a reactive molecular dynamics study JF - Applied Physics A N2 - In this work, extensive reactive molecular dynamics simulations are conducted to analyze the nanopore creation by nano-particles impact over single-layer molybdenum disulfide (MoS2) with 1T and 2H phases. We also compare the results with graphene monolayer. In our simulations, nanosheets are exposed to a spherical rigid carbon projectile with high initial velocities ranging from 2 to 23 km/s. Results for three different structures are compared to examine the most critical factors in the perforation and resistance force during the impact. To analyze the perforation and impact resistance, kinetic energy and displacement time history of the projectile as well as perforation resistance force of the projectile are investigated. Interestingly, although the elasticity module and tensile strength of the graphene are by almost five times higher than those of MoS2, the results demonstrate that 1T and 2H-MoS2 phases are more resistive to the impact loading and perforation than graphene. For the MoS2nanosheets, we realize that the 2H phase is more resistant to impact loading than the 1T counterpart. Our reactive molecular dynamics results highlight that in addition to the strength and toughness, atomic structure is another crucial factor that can contribute substantially to impact resistance of 2D materials. The obtained results can be useful to guide the experimental setups for the nanopore creation in MoS2or other 2D lattices. KW - Nanomechanik KW - Molekülstruktur KW - Nanoporöser Stoff KW - MoS2 KW - molecular dynamics KW - Nanopore KW - Graphene Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210804-44756 UR - https://link.springer.com/article/10.1007/s00339-021-04693-5 VL - 2021 IS - volume 127, article 541 SP - 1 EP - 13 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Nguyen-Xuan, Hung A1 - Rabczuk, Timon A1 - Nguyen-Thoi, T. A1 - Tran, T. A1 - Nguyen-Thanh, Nhon T1 - Computation of limit and shakedown loads using a node-based smoothed finite element method JF - International Journal for Numerical Methods in Engineering N2 - This paper presents a novel numerical procedure for computing limit and shakedown loads of structures using a node-based smoothed FEM in combination with a primal–dual algorithm. An associated primal–dual form based on the von Mises yield criterion is adopted. The primal-dual algorithm together with a Newton-like iteration are then used to solve this associated primal–dual form to determine simultaneously both approximate upper and quasi-lower bounds of the plastic collapse limit and the shakedown limit. The present formulation uses only linear approximations and its implementation into finite element programs is quite simple. Several numerical examples are given to show the reliability, accuracy, and generality of the present formulation compared with other available methods. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2012 U6 - http://dx.doi.org/10.1002/nme.3317 SP - 287 EP - 310 ER - TY - JOUR A1 - Nguyen-Xuan, Hung A1 - Rabczuk, Timon A1 - Nguyen-Thanh, Nhon A1 - Nguyen-Thoi, T. A1 - Bordas, Stéphane Pierre Alain T1 - A node-based smoothed finite element method (NS-FEM) for analysis of Reissner-Mindlin plates JF - Computational Mechanics N2 - A node-based smoothed finite element method (NS-FEM) for analysis of Reissner-Mindlin plates KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2010 SP - 679 EP - 701 ER - TY - JOUR A1 - Nguyen-Xuan, Hung A1 - Nguyen, Hiep Vinh A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon A1 - Duflot, Marc T1 - A cell-based smoothed finite element method for three dimensional solid structures JF - KSCE Journal of Civil Engineering N2 - 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. KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 U6 - http://dx.doi.org/10.1007/s12205-012-1515-7 SP - 1230 EP - 1242 ER - TY - JOUR A1 - Nguyen-Xuan, Hung A1 - Liu, G.R. A1 - Bordas, Stéphane Pierre Alain A1 - Natarajan, S. A1 - Rabczuk, Timon T1 - An adaptive singular ES-FEM for mechanics problems with singular field of arbitrary order JF - Computer Methods in Applied Mechanics and Engineering N2 - An adaptive singular ES-FEM for mechanics problems with singular field of arbitrary order KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 SP - 252 EP - 273 ER - TY - JOUR A1 - Nguyen-Vinh, H. A1 - Bakar, I. A1 - Msekh, Mohammed Abdulrazzak A1 - Song, Jeong-Hoon A1 - Muthu, Jacob A1 - Zi, Goangseup A1 - Le, P. A1 - Bordas, Stéphane Pierre Alain A1 - Simpson, R. A1 - Natarajan, S. A1 - Lahmer, Tom A1 - Rabczuk, Timon T1 - Extended Finite Element Method for Dynamic Fracture of Piezo-Electric Materials JF - Engineering Fracture Mechanics N2 - We present an extended finite element formulation for dynamic fracture of piezo-electric materials. The method is developed in the context of linear elastic fracture mechanics. It is applied to mode I and mixed mode-fracture for quasi-steady cracks. An implicit time integration scheme is exploited. The results are compared to results obtained with the boundary element method and show excellent agreement. KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.engfracmech.2012.04.025 SP - 19 EP - 31 ER - TY - JOUR A1 - Nguyen-Tuan, Long A1 - Lahmer, Tom A1 - Datcheva, Maria A1 - Stoimenova, Eugenia A1 - Schanz, Tom T1 - A novel parameter identification approach for buffer elements involving complex coupled thermo-hydro-mechanical analyses JF - Computers and Geotechnics N2 - A novel parameter identification approach for buffer elements involving complex coupled thermo-hydro-mechanical analyses KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 SP - 23 EP - 32 ER - TY - JOUR A1 - Nguyen-Tuan, Long A1 - Lahmer, Tom A1 - Datcheva, Maria A1 - Schanz, Tom T1 - Global and local sensitivity analyses for coupled thermo‐hydro‐mechanical problems JF - International Journal for Numerical and Analytical Methods in Geomechanics N2 - Global and local sensitivity analyses for coupled thermo‐hydro‐mechanical problems KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 ER - TY - JOUR A1 - Nguyen-Tuan, Long A1 - Könke, Carsten A1 - Bettzieche, Volker A1 - Lahmer, Tom T1 - Numerical modeling and validation for 3D coupled-nonlinear thermo-hydro-mechanical problems in masonry dams JF - Computers & Structures N2 - Numerical modeling and validation for 3D coupled-nonlinear thermo-hydro-mechanical problems in masonry dams KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2017 SP - 143 EP - 154 ER - TY - JOUR A1 - Nguyen-Thoi, T. A1 - Rabczuk, Timon A1 - Lam-Phat, T. A1 - Ho-Huu, V. A1 - Phung-Van, P. T1 - Free vibration analysis of cracked Mindlin plate using an extended cell-based smoothed discrete shear gap method (XCS-DSG3) JF - Theoretical and Applied Fracture Mechanics N2 - Free vibration analysis of cracked Mindlin plate using an extended cell-based smoothed discrete shear gap method (XCS-DSG3) KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Nguyen-Thoi, T. A1 - Phung-Van, P. A1 - Rabczuk, Timon A1 - Nguyen-Xuan, Hung A1 - Le-Van, C. T1 - An application of the ES-FEM in solid domain for dynamic analysis of 2D fluid-solid interaction problems JF - International Journal of Computational Methods N2 - An application of the ES-FEM in solid domain for dynamic analysis of 2D fluid-solid interaction problems KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Nguyen-Thoi, T. A1 - Phung-Van, P. A1 - Rabczuk, Timon A1 - Nguyen-Xuan, Hung A1 - Le-Van, C. T1 - Free and forced vibration analysis using the n-sided polygonal cell-based smoothed finite element method (nCS-FEM) JF - International Journal of Computational Methods N2 - Free and forced vibration analysis using the n-sided polygonal cell-based smoothed finite element method (nCS-FEM) KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2013 ER - TY - JOUR A1 - Nguyen-Thanh, Nhon A1 - Valizadeh, Navid A1 - Nguyen, Manh Hung A1 - Nguyen-Xuan, Hung A1 - Zhuang, Xiaoying A1 - Areias, Pedro A1 - Zi, Goangseup A1 - Bazilevs, Yuri A1 - De Lorenzis, Laura A1 - Rabczuk, Timon T1 - An extended isogeometric thin shell analysis based on Kirchhoff-Love theory JF - Computer Methods in Applied Mechanics and Engineering N2 - An extended isogeometric thin shell analysis based on Kirchho_-Love theory KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2015 SP - 265 EP - 291 ER - TY - JOUR A1 - Nguyen-Thanh, Nhon A1 - Thai-Hoang, C. A1 - Nguyen-Xuan, Hung A1 - Rabczuk, Timon T1 - A smoothed finite element method for the static and free vibration analysis of shells JF - Journal of Civil Engineering and Architecture N2 - A smoothed finite element method for the static and free vibration analysis of shells KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2010 SP - 13 EP - 25 ER - TY - JOUR A1 - Nguyen-Thanh, Nhon A1 - Rabczuk, Timon A1 - Nguyen-Xuan, Hung A1 - Bordas, Stéphane Pierre Alain T1 - An alternative alpha finite element method with stabilized discrete shear gap technique for analysis of Mindlin-Reissner plates JF - Finite Elements in Analysis & Design N2 - An alternative alpha finite element method with stabilized discrete shear gap technique for analysis of Mindlin-Reissner plates KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2011 SP - 519 EP - 535 ER - TY - JOUR A1 - Nguyen-Thanh, Nhon A1 - Rabczuk, Timon A1 - Nguyen-Xuan, Hung A1 - Bordas, Stéphane Pierre Alain T1 - An alternative alpha finite element method (A?FEM) free and forced vibration analysis of solids using triangular meshes JF - Journal of Computational and Applied Mathematics N2 - An alternative alpha finite element method (A?FEM) free and forced vibration analysis of solids using triangular meshes KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2009 SP - 2112 EP - 2135 ER - TY - JOUR A1 - Nguyen-Thanh, Nhon A1 - Nguyen-Xuan, Hung A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon T1 - Isogeometric analysis using polynomial splines over hierarchical T-meshes for two-dimensional elastic solids JF - Computer Methods in Applied Mechanics and Engineering N2 - Isogeometric analysis using polynomial splines over hierarchical T-meshes for two-dimensional elastic solids KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2011 SP - 1892 EP - 1908 ER - TY - JOUR A1 - Nguyen-Thanh, Nhon A1 - Muthu, Jacob A1 - Zhuang, Xiaoying A1 - Rabczuk, Timon T1 - An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics JF - Computational Mechanics N2 - An adaptive three-dimensional RHT-splines formulation in linear elasto-statics and elasto-dynamics KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 SP - 369 EP - 385 ER - TY - JOUR A1 - Nguyen-Thanh, Nhon A1 - Kiendl, J. A1 - Nguyen-Xuan, Hung A1 - Wüchner, R. A1 - Bletzinger, Kai-Uwe A1 - Bazilevs, Yuri A1 - Rabczuk, Timon T1 - Rotation free isogeometric thin shell analysis using PHT-splines JF - Computer Methods in Applied Mechanics and Engineering N2 - Rotation free isogeometric thin shell analysis using PHT-splines KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2011 SP - 3410 EP - 3424 ER - TY - JOUR A1 - Nguyen, V.P. A1 - Kerfriden, Pierre A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon T1 - Isogeometric analysis suitable trivariate NURBS representation of composite panels with a new offset algorithm JF - Computer-Aided Design N2 - Isogeometric analysis suitable trivariate NURBS representation of composite panels with a new offset algorithm KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2014 ER - TY - JOUR A1 - Natarajan, S. A1 - Chakraborty, S. A1 - Thangavel, M. A1 - Bordas, Stéphane Pierre Alain A1 - Rabczuk, Timon T1 - Size dependent free flexural vibration behavior of functionally graded nanoplates JF - Computational Materials Science N2 - Size dependent free flexural vibration behavior of functionally graded nanoplates KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2012 SP - 74 EP - 80 ER - TY - JOUR A1 - Nasser, Mourad A1 - Schwedler, Michael A1 - Wuttke, Frank A1 - Könke, Carsten T1 - Seismic analysis of structural response using simplified soil-structure interaction models JF - Bauingenieur, D-A-CH-Mitteilungsblatt N2 - Seismic analysis of structural response using simplified soil-structure interaction models KW - Angewandte Mathematik KW - Strukturmechanik Y1 - 2010 ER - TY - JOUR A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Zhuang, Xiaoying A1 - Zi, Goangseup A1 - Rabczuk, Timon T1 - Detection of material interfaces using a regularized level set method in piezoelectric structures JF - Inverse Problems in Science and Engineering N2 - Detection of material interfaces using a regularized level set method in piezoelectric structures KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 SP - 153 EP - 176 ER - TY - JOUR A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Zhuang, Xiaoying A1 - Zi, Goangseup A1 - Rabczuk, Timon T1 - Detection of material interfaces using a regularized level set method in piezoelectric structures JF - Inverse Problems in Science and Engineering N2 - Detection of material interfaces using a regularized level set method in piezoelectric structures KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2015 ER - TY - JOUR A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Zhuang, Xiaoying A1 - Park, Harold S. A1 - Rabczuk, Timon T1 - Topology optimization of piezoelectric nanostructures JF - Journal of the Mechanics and Physics of Solids N2 - Topology optimization of piezoelectric nanostructures KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 SP - 316 EP - 335 ER - TY - JOUR A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Rabczuk, Timon T1 - Detection of flaws in piezoelectric structures using extended FEM JF - International Journal for Numerical Methods in Engineering N2 - Detection of flaws in piezoelectric structures using extended FEM KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2013 SP - 373 EP - 389 ER - TY - JOUR A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Rabczuk, Timon T1 - Detection of multiple flaws in piezoelectric structures using XFEM and level sets JF - International Journal for Numerical Methods in Engineering N2 - Detection of multiple flaws in piezoelectric structures using XFEM and level sets KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2016 SP - 960 ER - TY - JOUR A1 - Nanthakumar, S.S. A1 - Lahmer, Tom A1 - Rabczuk, Timon T1 - Detection of multiple flaws in piezoelectric structures using XFEM and level sets JF - Computer Methods in Applied Mechanics and Engineering N2 - Detection of multiple flaws in piezoelectric structures using XFEM and level sets KW - Angewandte Mathematik KW - Stochastik KW - Strukturmechanik Y1 - 2014 SP - 98 EP - 112 ER - TY - JOUR A1 - Nabipour, Narjes A1 - Mosavi, Amir A1 - Baghban, Alireza A1 - Shamshirband, Shahaboddin A1 - Felde, Imre T1 - Extreme Learning Machine-Based Model for Solubility Estimation of Hydrocarbon Gases in Electrolyte Solutions JF - Processes N2 - Calculating hydrocarbon components solubility of natural gases is known as one of the important issues for operational works in petroleum and chemical engineering. In this work, a novel solubility estimation tool has been proposed for hydrocarbon gases—including methane, ethane, propane, and butane—in aqueous electrolyte solutions based on extreme learning machine (ELM) algorithm. Comparing the ELM outputs with a comprehensive real databank which has 1175 solubility points yielded R-squared values of 0.985 and 0.987 for training and testing phases respectively. Furthermore, the visual comparison of estimated and actual hydrocarbon solubility led to confirm the ability of proposed solubility model. Additionally, sensitivity analysis has been employed on the input variables of model to identify their impacts on hydrocarbon solubility. Such a comprehensive and reliable study can help engineers and scientists to successfully determine the important thermodynamic properties, which are key factors in optimizing and designing different industrial units such as refineries and petrochemical plants. KW - Maschinelles Lernen KW - Machine learning KW - Deep learning Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20200113-40624 UR - https://www.mdpi.com/2227-9717/8/1/92 VL - 2020 IS - Volume 8, Issue 1, 92 PB - MDPI ER -