Development of mesoscopic field dislocation mechanics finite element model and application in microplasticity

Abstract

In the present paper, a three‐dimensional implementation of mesoscopic field dislocation mechanics is presented. This model describes the evolution of dislocation fields during plastic deformation. Since the elastic interaction of dislocations is considered directly, it is possible to study the plastic response at the mesoscale without introducing length scales as model parameters. The model is embedded in a crystal plasticity framework which is numerically implemented by the finite element method. As a test problem, the simple shearing of a composite with different sizes of reinforcement is simulated. It is shown that the model is able to reproduce the size effect that is observed in deformed composite materials.

Keywords:

• Field dislocation mechanics
• Size effect
• Dislocation evolution

This work was supported by Natural Scientific Research Innovation Foundation in Harbin Institute of Technology (grant no. HIT.NSRIF.2008·37) and the National Natural Science Foundation of China (grant no. 50605016). Useful discussions with Professor Claude Fressengeas are acknowledged.