Model Order Reduction Methods for Explicit FEM.

Abaqus/Explicit is a well-established and widely used FEM solver for crash and pedestrian safety simulations. However, due to the large number of degrees of freedom, simulation time is still a limiting factor especially in context of structural optimization. In typical crash simulation, a large portion of the model undergoes only elastic deformation. Hence, model order reduction (MOR) methods can bring a significant decrease in the computational time. While Abaqus/Standard already offers several reduction methods, MOR is currently not applicable for Abaqus/Explicit. The purpose of this work is to enable MOR for explicit finite element models by use of superelements. Reduced mass and stiffness matrices are generated by Abaqus/Standard and transferred to the explicit solver through a VUEL subroutine. The method is applied successfully to low speed vehicle crash simulations. The achieved results show a significant gain in computational time and underline the potential of MOR for Abaqus/Explicit.