@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{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{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{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{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{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{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{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{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{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} }