@article{NohPark2004, author = {Noh, Jung-Hwi and Park, Jong-Heon}, title = {A Calculation of Initial Cable Force for Ko-Ha Grand Bridge}, doi = {10.25643/bauhaus-universitaet.245}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2459}, year = {2004}, abstract = {The primary objective of initial shape analysis of a cable stayed bridge is to calculate initial installation cable tension forces and to evaluate fabrication camber of main span and pylon providing the final longitudinal profile of the bridge at the end of construction. In addition, the initial cable forces depending on the alternation of the bridge's shape can be obtained from the analysis, and will be used to provide construction safety during construction. In this research, we conducted numerical experiments for initial shape of Ko-ha bridge, which will be constructed in the near future, using three different typical methods such as continuous beam method, linear truss method, and IIMF (Introducing Initial Member Force) method}, subject = {Finite-Elemente-Methode}, language = {en} } @article{IbanezKraus, author = {Ibanez, Stalin and Kraus, Matthias}, title = {A Numerical Approach for Plastic Cross Cross-Sectional Analyses of Steel Members}, series = {ce/papers}, volume = {2021}, journal = {ce/papers}, number = {Volume 4, issue 2-4}, publisher = {Ernst \& Sohn, a Wiley brand}, address = {Berlin}, doi = {10.1002/cepa.1527}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220112-45622}, pages = {2098 -- 2106}, abstract = {Global structural analyses in civil engineering are usually performed considering linear-elastic material behavior. However, for steel structures, a certain degree of plasticization depending on the member classification may be considered. Corresponding plastic analyses taking material nonlinearities into account are effectively realized using numerical methods. Frequently applied finite elements of two and three-dimensional models evaluate the plasticity at defined nodes using a yield surface, i.e. by a yield condition, hardening rule, and flow rule. Corresponding calculations are connected to a large numerical as well as time-consuming effort and they do not rely on the theoretical background of beam theory, to which the regulations of standards mainly correspond. For that reason, methods using beam elements (one-dimensional) combined with cross-sectional analyses are commonly applied for steel members in terms of plastic zones theories. In these approaches, plasticization is in general assessed by means of axial stress only. In this paper, more precise numerical representation of the combined stress states, i.e. axial and shear stresses, is presented and results of the proposed approach are validated and discussed.}, subject = {Stahlkonstruktion}, language = {en} } @article{VuBacNguyenXuanChenetal., author = {Vu-Bac, N. and Nguyen-Xuan, Hung and Chen, Lei and Lee, C.K. and Zi, Goangseup and Zhuang, Xiaoying and Liu, G.R. and Rabczuk, Timon}, title = {A phantom-node method with edge-based strain smoothing for linear elastic fracture mechanics}, series = {Journal of Applied Mathematics}, journal = {Journal of Applied Mathematics}, doi = {10.1155/2013/978026}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170426-31676}, abstract = {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.}, subject = {Finite-Elemente-Methode}, language = {en} } @article{MironovPahl2004, author = {Mironov, Vadim and Pahl, Peter Jan}, title = {A Prismatic Finite Element for Accurate Arch Dam Analysis}, doi = {10.25643/bauhaus-universitaet.246}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2467}, year = {2004}, abstract = {The displacements and stresses in arch dams and their abutments are frequently determined with 20-node brick elements. The elements are distorted near the contact plane between the wall and the abutment. A cantilever beam testbed has been developed to investigate the consequences of this distortion. It is shown that the deterioration of the accuracy in the computed stresses is significant. A compatible 18-node wedge element with linear stress variation is developed as an alternative to the brick element. The shape of this element type is readily adapted to the shape of the contact plane. It is shown that the accuracy of the computed stresses in the vicinity of the contact plane is improved significantly by the use of wedge elements.}, subject = {Finite-Elemente-Methode}, language = {en} } @article{TalebiZiSilanietal., author = {Talebi, Hossein and Zi, Goangseup and Silani, Mohammad and Samaniego, Esteban and Rabczuk, Timon}, title = {A simple circular cell method for multilevel finite element analysis}, series = {Journal of Applied Mathematics}, journal = {Journal of Applied Mathematics}, doi = {10.1155/2012/526846}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170426-31639}, abstract = {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.}, subject = {Finite-Elemente-Methode}, language = {en} } @article{LeeLee2004, author = {Lee, Kangkun and Lee, Kijang}, title = {Additional bending moment for shear-lag phenomenon in tube structures}, doi = {10.25643/bauhaus-universitaet.247}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2472}, year = {2004}, abstract = {Framed-tube system with multiple internal tubes is analysed using an orthotropic box beam analogy approach in which each tube is individually modelled by a box beam that accounts for the flexural and shear deformations, as well as the shear-lag effects. A simple numerical modeling technique is proposed for estimating the shear-lag phenomenon in tube structures with multiple internal tubes. The proposed method idealizes the framed-tube structures with multiple internal tubes as equivalent multiple tubes, each composed of four equivalent orthotropic plate panels. The numerical analysis is based on the minimum potential energy principle in conjunction with the variational approach. The shear-lag phenomenon of such structures is studied taking into account the additional bending moments in the tubes. A detailed work is carried out through the numerical analysis of the additional bending moment. The moment factor is further introduced to identify the shear lag phenomenon along with the additional moment.}, subject = {Finite-Elemente-Methode}, language = {en} } @article{MostEckardt2004, author = {Most, Thomas and Eckardt, Stefan}, title = {Application of a hybrid parallelization technique to accelerate the numerical simulation of nonlinear mechanical problems}, doi = {10.25643/bauhaus-universitaet.259}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2599}, year = {2004}, abstract = {This paper presents the combination of two different parallelization environments, OpenMP and MPI, in one numerical simulation tool. The computation of the system matrices and vectors is parallelized with OpenMP and the solution of the system of equations is done with the MPIbased solver MUMPS. The efficiency of both algorithms is shown on several linear and nonlinear examples using the Finite Element Method and a meshless discretization technique.}, subject = {Framework }, language = {en} } @article{MelnikovSemenov2004, author = {Melnikov, B. E. and Semenov, Artem}, title = {Application of Multimodel Method of Elasto-Plastic Analysis for the Multilevel Computation of Structures}, doi = {10.25643/bauhaus-universitaet.248}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2487}, year = {2004}, abstract = {Creation of hierarchical sequence of the plastic and viscoplastic models according to different levels of structure approximations is considered. Developed strategy of multimodel analysis, which consists of creation of the inelastic models library, determination of selection criteria system and caring out of multivariant sequential clarifying computations, is described. Application of the multimodel approach in numerical computations has demonstrated possibility of reliable prediction of stress-strain response under wide variety of combined nonproportional loading.}, subject = {Finite-Elemente-Methode}, language = {en} } @article{ReichertOlneyLahmer, author = {Reichert, Ina and Olney, Peter and Lahmer, Tom}, title = {Combined approach for optimal sensor placement and experimental verification in the context of tower-like structures}, series = {Journal of Civil Structural Health Monitoring}, volume = {2021}, journal = {Journal of Civil Structural Health Monitoring}, number = {volume 11}, publisher = {Heidelberg}, address = {Springer}, doi = {10.1007/s13349-020-00448-7}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210804-44701}, pages = {223 -- 234}, abstract = {When it comes to monitoring of huge structures, main issues are limited time, high costs and how to deal with the big amount of data. In order to reduce and manage them, respectively, methods from the field of optimal design of experiments are useful and supportive. Having optimal experimental designs at hand before conducting any measurements is leading to a highly informative measurement concept, where the sensor positions are optimized according to minimal errors in the structures' models. For the reduction of computational time a combined approach using Fisher Information Matrix and mean-squared error in a two-step procedure is proposed under the consideration of different error types. The error descriptions contain random/aleatoric and systematic/epistemic portions. Applying this combined approach on a finite element model using artificial acceleration time measurement data with artificially added errors leads to the optimized sensor positions. These findings are compared to results from laboratory experiments on the modeled structure, which is a tower-like structure represented by a hollow pipe as the cantilever beam. Conclusively, the combined approach is leading to a sound experimental design that leads to a good estimate of the structure's behavior and model parameters without the need of preliminary measurements for model updating.}, subject = {Strukturmechanik}, 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} }