A heuristic attempt to reduce transverse shear locking in fully integrated hexahedra with poor aspect ratio

In an attempt to alleviate transverse shear locking in fully integrated hexahedra elements with poor aspect ratio, two new variants of solid element type 2 in LS-DYNA have been developed, implemented and tested on some critical problems. The approach is based on modifying the jacobian matrix in such a way that the spurious stiffness is reduced without affecting the true physical behavior of the element. The method is in a sense justified by means of a theoretical motivation, but above all indicated to be of practical use through some illustrating examples. The two new solid elements are termed type-1 and -2, where the latter is more rigorous but suffers from a higher computational expense, whereas solid element type-1 has an efficiency slightly worse than solid element type-2 for explicit analyses. However, all three element types are in that sense comparable for large scale implicit analyses.