- Standard and 3D shell models
- Kinematic extension of standard shell models
- Numerical efficiency: Locking and critical time step size
Standard and 3D shell models
Finite element simulation is an established tool in industrial practice for the evaluation of sheet metal forming processes. Simulating certain sheet metal forming processes, state of the art shell elements reach their limits. Examples for such critical forming processes are forming of thick sheets and forming at small radii. Assumptions of standard shell formulations, e.g. neglecting normal stresses in thickness direction as well as the hypothesis that plane sections remain plane, are not met in these forming processes. Recently implemented 3D shell elements and solid shell elements allow the usage of a three-dimensional material law but hardly improve geometric modelling.
Kinematic extension of standard shell models
Numerical efficiency: Locking and critical time step size
In addition to enhancing the shell kinematics, there is a focus on the numerical efficiency of the elements to be developed to make them suitable for large-scale industrial simulations. Two aspects will be covered: Firstly, the elimination of existing and prevention of new locking phenomena. Secondly, enhancing the shell kinematics typically results in a reduction of the critical time step size. By using mass scaling, it is possible to reduce or even avoid this reduction.
Verbesserte Blechumformsimulation durch 3D-Werkstoffmodelle und erweiterte Schalenformulierungen
AiF-Nr.: 19707N; EFB-Nr.: 09/117
Fraunhofer Institute for Mechanics of Materials (IWM), Freiburg