线搜索增强的率相关晶体塑性本构积分算法及数值实现

The theory of crystal plasticity constitutive law, which is based on the micromechanics of crystal deformation, has been applied in studying the deformation of crystal materials on meso-scale. In integration methods of rate-dependent crystal plasticity constitutive equations, Newton-Raphson (N-R) iteration is always adopted as the core algorithm in solving increments of shear strain. In order to improve the efficiency, line search method was utilized to modify the step length of N-R iteration in the theory; then, the integration methods of crystal plasticity constitutive law with normal and line search enhanced N-R iteration were programmed into subroutines. The simulations of monotonic tensile mechanical behavior of Ni-based polycrystal superalloy were conducted with different subroutines. And the simulated results and computation efficiency were compared and analyzed. The results show that the tensile mechanical behavior is simulated by both subroutines and the results are identical. Furthermore, the consumed total number of increments and the time cost of the simulation with line search enhanced subroutine are 1/5, 1/6 respectively of that without line search method.