A gradient plasticity grain boundary yield theory

A strain gradient crystal plasticity theory is presented that accounts for the resistance of grain boundaries against plastic flow based on an interface yield condition. This theory incorporates the previously presented numerically efficient visco-plastic treatment by the gradient of an equivalent plastic strain image in . The finite element implementation is discussed and the three-dimensional numerical model is fitted to experimental data of polycrystalline copper micro-tensile tests. The size dependent yield strength is reproduced notably well.