Session Details

10:30
Forming simulations with NURBS shells in LS-DYNA
Stefan Hartmann (DYNAmore GmbH), Attila P. Nagy (Livermore Software Technology Corporation (LSTC)), Dave J. Benson (Livermore Software Technology Corporation (LSTC))

Kurzfassung:
LSTC (Livermore Software Technology Corp.) has started to implement NURBS based finite elements into their widely used commercial simulation package LS-DYNA. This work will give a short overview about the general possibilities of isogeometric shells in LS-DYNA and focus on the recent advances for the analysis of Sheet Metal Forming Applications. A benchmark example from the Numisheet 2005 conference is analyzed and compared with the results achieved with state-of-the-art methods.

10:50
A mixed isogeometric collocation method for rate-independent elastoplasticity
Frederik Fahrendorf (Technical University of Braunschweig), Laura De Lorenzis (Technical University of Braunschweig)

Kurzfassung:
We present a mixed isogeometric collocation method for rate-independent elastoplasticity at small strains. In the proposed approach, both stress and displacement fields are approximated as primary variables. An isotropic hardening rule is implemented and the elastoplastic constitutive equations are integrated in time via a classical return-mapping algorithm. Various numerical examples of plane strain elastoplasticity are investigated and compared to reference solutions.

11:10
A scaled boundary NURBS approach for nonlinear solid analysis
Markus Klassen (RWTH Aachen University), Margarita Chasapi (RWTH Aachen University), Bernd Simeon (University of Kaiserslautern), Sven Klinkel (RWTH Aachen University)

Kurzfassung:
In this contribution, the scaled boundary formulation is proposed as a discretization technique which is based on the isogeometric concept. By this means, the representation of a solid body is given by the boundary surface of the body and a radial scaling parameter which is used to describe the interior. NURBS shape functions are employed to define the geometry as well as to approximate the solution field. The numerical examples are given for elasto-plastic material behavior at small strains.

11:30
Simulation of brittle fracture in shells using a phase-field approach and LR B-splines
Davide Proserpio (Norwegian University of Science and Technology), Josef Kiendl (Norwegian University of Science and Technology), Marreddy Ambati (Technical University of Braunschweig), Laura De Lorenzis (Technical University of Braunschweig), Kjetil André Johannessen (Norwegian University of Science and Technology), Trond Kvamsdal (Norwegian University of Science and Technology)

Kurzfassung:
We present a phase-field approach to model brittle fracture in plates and shells. For structural analysis, the discretization of the geometry is performed using an isogeometric Kirchhoff-Love shell formulation, extended to local refinement with LR B-splines in order to properly resolve the mesh in the cracked regions, improving the accuracy and efficiency of the analysis.

11:50
A shell element for the analysis of interlaminar stresses and delaminations of layered composites
Gregor Knust (Technical University of Darmstadt), Friedrich Gruttmann (Technical University of Darmstadt)

Kurzfassung:
In this contribution a mixed hybrid shell element for the calculation of interlaminar shear and normal thickness stresses of layered composite structures is presented. These stresses are decisive factors for delaminations. The element formulation is based on the Reisser-Mindlin kinematics with an inextensible director field. After static condensation the element has the standard shell degrees of freedom. The numerical examples focus on failure caused by delamination.