DYNA3D ANALYSIS OF DYNAMIC FRACTURE OF WELDMENTS

A local ductile fracture model was developed and implemented into the finite element code DYNA3D. The local fracture model calculates damage in each element as a function of the stress state and plastic strain increments. Crack propagation is modeled by discrete separation of the elements through the fully damaged regions of the mesh. We applied the fracture model to simulate the behavior of dynamic fracture experiments on welded steel specimens. The local damage model successfully reproduced the experimentally observed fracture behavior including following the crack path through the steel plate. We then used the method to illustrate how to design stronger and safer weldments for metal structures subjected to earthquake loadings. 1