Iteration Process in FRACOD

Abstract

This chapter describe the iteration process used in FRACOD. Boundary element methods (including DDM) are implicit numerical methods. This means that the numerical calculation will only provide a final solution at given stress or displacement boundary conditions, ignoring the linearity of the process that reaches the final solution. For elastic problems, the implicit method is the most efficient and straightforward way to get the final solution because of the linear stress–strain relation. However, for plasticity problems caused by joint sliding and fracture propagation, the implicit method can give false results if the process to reach the final solution is non-linear. Final solutions will then depend on the path of loading. Iteration process is an effective method to consider the path dependent problem.