Computationally modeling dynamic fracture: Improving existing methods and exploring new methods

Charles Gerlach, Northwestern University

The Element-Free Galerkin method has already been demonstrated to accurately model dynamic fracture problems. However, it did not have an obvious means of modeling contact across crack faces. The means of modeling contact will be briefly outlined, and results shown.

The Partition of Unity Finite Element Method (PU-FEM) has recently come to light, and been applied to static crack problems. It is a consistent means of extrinsically enriching a sub-set of finite elements in the model with linearly independent functions. When these functions are chosen to be a set which can construct the near-tip asymptotic crack fields, then an arbitrary crack can be accurately modeled, by even a relatively coarse mesh.

Since PU-FEM seems to be a robust, accurate method in statics, I have attempted to apply it to dynamic problems. The formulation of the problem has to be dealt with carefully, since a propagating crack causes the shape functions themselves to be time-dependent. The formulation will be explained, and results shown.

Abstract Author(s): Charles Gerlach