@misc{Gundermann2005,
  type      = {Master Thesis},
  author    = {Gundermann, Ralf},
  title     = {3D-Simulation des Temperaturfeldes und der Gef{\"u}geumwandlung bei einer Laserstrahlschweißung},
  doi       = {10.25643/bauhaus-universitaet.668},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-6680},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  year      = {2005},
  abstract  = {Das FEM-Programmsystem „SYSWELD" kommt f{\"u}r die Berechnung des Temperaturfeldes bei einer Laserstrahlschweißung zum Einsatz. Insbesondere sollen der Einfluss des Energieeintrages und die damit verbundene Gef{\"u}geumwandlung eines Feinkornbaustahles untersucht und Aussagen zur notwendigen Modellierungsgenauigkeit der Nahtgeometrie bzw. Netzverfeinerung getroffen werden. Im Einzelnen sind folgende Teilaufgaben zu l{\"o}sen: - ausf{\"u}hrliche Literaturrecherche zur numerischen Analyse von Schweißverbindungen insbesondere zu temperaturabh{\"a}ngigen Materialeigenschaften von Feinkornbaust{\"a}hlen, - Darstellung der W{\"a}rmequelle f{\"u}r das Laserstrahlschweißen, - Erprobung unterschiedlicher Netzvarianten f{\"u}r die FE-Analyse von instation{\"a}ren Temperaturfeldern, - Untersuchung zur Modellierungsgenauigkeit der Nahtgeometrie, - Parameterstudien zum Einfluss der Materialkennwerte und Gef{\"u}gekinetik auf das Temperaturfeld sowie das Gef{\"u}ge.},
  subject      = {Laserschweißen},
  language  = {de}
}
@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}
}
@inproceedings{BrehmMost2003,
  author    = {Brehm, Maik and Most, Thomas},
  title     = {A Four-Node Plane EAS-Element for Stochastic Nonlinear Materials},
  doi       = {10.25643/bauhaus-universitaet.282},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-2825},
  year      = {2003},
  abstract  = {Iso-parametric finite elements with linear shape functions show in general a too stiff element behavior, called locking. By the investigation of structural parts under bending loading the so-called shear locking appears, because these elements can not reproduce pure bending modes. Many studies dealt with the locking problem and a number of methods to avoid the undesirable effects have been developed. Two well known methods are the >Assumed Natural Strain< (ANS) method and the >Enhanced Assumed Strain< (EAS) method. In this study the EAS method is applied to a four-node plane element with four EAS-parameters. The paper will describe the well-known linear formulation, its extension to nonlinear materials and the modeling of material uncertainties with random fields. For nonlinear material behavior the EAS parameters can not be determined directly. Here the problem is solved by using an internal iteration at the element level, which is much more efficient and stable than the determination via a global iteration. To verify the deterministic element behavior the results of common test examples are presented for linear and nonlinear materials. The modeling of material uncertainties is done by point-discretized random fields. To show the applicability of the element for stochastic finite element calculations Latin Hypercube Sampling was applied to investigate the stochastic hardening behavior of a cantilever beam with nonlinear material. The enhanced linear element can be applied as an alternative to higher-order finite elements where more nodes are necessary. The presented element formulation can be used in a similar manner to improve stochastic linear solid elements.},
  subject      = {Nichtlineare Mechanik},
  language  = {en}
}
@inproceedings{HaefnerEckardtKoenke2003,
  author    = {H{\"a}fner, Stefan and Eckardt, Stefan and K{\"o}nke, Carsten},
  title     = {A geometrical inclusion-matrix model for the finite element analysis of concrete at multiple scales},
  doi       = {10.25643/bauhaus-universitaet.301},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3018},
  year      = {2003},
  abstract  = {This paper introduces a method to generate adequate inclusion-matrix geometries of concrete in two and three dimensions, which are independent of any specific numerical discretization. The article starts with an analysis on shapes of natural aggregates and discusses corresponding mathematical realizations. As a first prototype a two-dimensional generation of a mesoscale model is introduced. Particle size distribution functions are analysed and prepared for simulating an adequate three-dimensional representation of the aggregates within a concrete structure. A sample geometry of a three-dimensional test cube is generated and the finite element analysis of its heterogeneous geometry by a uniform mesh is presented. Concluding, aspects of a multiscale analysis are discussed and possible enhancements are proposed.},
  subject      = {Beton},
  language  = {en}
}
@inproceedings{Montag1997,
  author    = {Montag, U.},
  title     = {A New Efficient Concept for Elasto-plastic Simulations of Shell Responses},
  doi       = {10.25643/bauhaus-universitaet.436},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4364},
  year      = {1997},
  abstract  = {For the analysis of arbitrary, by Finite Elements discretized shell structures, an efficient numerical simulation strategy with quadratic convergence including geometrically and physically nonlinear effects will be presented. In the beginning, a Finite-Rotation shell theory allowing constant shear deformations across the shell thickness is given in an isoparametric formulation. The assumed-strain concept enables the derivation of a locking-free finite element. The Layered Approach will be applied to ensure a sufficiently precise prediction of the propagation of plastic zones even throughout the shell thickness. The Riks-Wempner-Wessels global iteration scheme will be enhanced by a Line-Search procedure to ensure the tracing of nonlinear deformation paths with rather great load steps even in the post-peak range. The elastic-plastic material model includes isotropic hardening. A new Operator-Split return algorithm ensures considerably exact solution of the initial-value problem even for greater load steps. The combination with consistently linearized constitutive equations ensures quadratic convergence in a close neighbourhood to the exact solution. Finally, several examples will demonstrate accuracy and numerical efficiency of the developed algorithm.},
  subject      = {Schale},
  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}
}
@inproceedings{Skrinar1997,
  author    = {Skrinar, Matjaz},
  title     = {A simple FEM Beam Element with an Arbitrary Number of Cracks},
  doi       = {10.25643/bauhaus-universitaet.428},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-4287},
  year      = {1997},
  abstract  = {To fulfil safety requirements the changes in the static and/or dynamic behaviour of the structure must be analysed with great care. These changes are often caused by local reduction of the stiffness of the structure caused by the irregularities in the structure, as for example cracks. In simple structures such analysis can be performed directly, by solving equations of motion, but for more complex structures a different approach, usually numerical, must be applied. The problem of crack implementation into the structure behaviour has been studied by many authors who have usually modelled the crack as a massless rotational spring of suitable stiffness placed at the beam at the location where the crack occurs. Recently, the numerical procedure for the computation of the stiffness matrix for a beam element with a single transverse crack has been replaced with the element stiffness matrix written in fully symbolic form. A detailed comparison of the results obtained by using 200 2D finite elements with those obtained with a single cracked beam element has confirmed the usefulness of such element.},
  subject      = {Finite-Elemente-Methode},
  language  = {en}
}