Abstract
A mean-field model is established for solving the interaction between a twin and a parent. A twin is modeled as a thin plate embedded in the parent. The compatibility and force equilibrium on the twin boundary are enforced. Integrating this model to a finite element method, strain localization in AZ31 sheet is simulated. This approach is able to predict the occurrence of contraction twin and fracture induced by accumulation of slips in the twin region.