A TWO-SCALE STRONG DISCONTINUITY APPROACH FOR EVOLUTION OF SHEAR BANDS UNDER DYNAMIC IMPACT LOADS

摘要

A micro-macro two-scale method for modeling adiabatic shear bands in rate-dependent materials is presented. The phantom node method, which is a variant of the extended finite element method is used to model the shear band at the macroscale. The key contribution is the development of a micromodel which allows the extraction of tangential and normal traction-separation laws, i.e., cohesive laws. These extracted rate-dependent cohesive laws are then injected back into the macro scale to accurately model the postlocalization behavior. The results show good accuracy as compared to very fine finite element meshes but are orders of magnitude faster. Hence the scheme is attractive when tracking of shear bands is of greater importance than microscopic behavior.