磁电弹复合材料和刚性导电导磁圆柱压头的二维微动接触分析

本文求解平面应变状态下磁电弹复合材料半平面和刚性导电导磁圆柱压头的二维微动接触问题。假设压头具有良好的导电导磁性，且表面电势和磁势是常数。微动接触依赖载荷的加载历史，所以首先求解单独的法向加载问题，然后在法向加载问题的基础上求解循环变化的切向加载问题。整个接触区可以分为内部的中心粘着区和两个外部的滑移区，其中滑移区满足Coulomb摩擦法则。利用Fourier积分变换，磁电弹半平面的微动接触问题将简化为耦合的Cauchy奇异积分方程组，然后数值离散为线性代数方程组，利用迭代法求解未知的粘着/滑移区尺寸、电荷分布、磁感应强度、法向接触压力和切向接触力。数值算例给出了摩擦系数、总电荷和总磁感应强度对各加载阶段的表面接触应力、电位移和磁感应强度的影响。

THE EFFECTS OF HETEROGENEOUS DEFORMATION ON VOID GROWTH IN FCC CRYSTALS

To investigate the influence of crystallographic orientation and deformation mismatch on void growth and coalescence,a unit cell including a spherical void was used to study the growth behavior of voids in single crystals and voids located at grain boundary in FCC crystals by using 3D crystal plasticity finite element method.Simulation results show that the void shape and growth velocity significantly depend on the crystallographic orientation.Due to inter-grain heterogeneous deformation,the growth of void located at the grain boundary accelerated,and the growth rate of voids at the grain boundary of the two-grain is faster than that in single crystal.With the orientation factor's difference between the two grains increasing,the void prefers to grow along the grain boundary.