中文摘要：

针对传统有限元方法过度依赖于网格,计算时磨粒和工件接触区域的网格畸变严重,很难模拟脆性材料加工中材料内部裂纹的形成过程这一问题,利用光滑粒子流体动力学法建立单个磨粒切削加工过程的FE/SPH耦合有限元模型,对熔石英材料研磨过程进行数值模拟,为脆性材料切削过程的仿真提供了新途径.系统分析研磨加工中亚表层裂纹的形成过程以及切削参数对亚表层裂纹深度的影响规律.仿真结果表明：磨粒刚开始切入工件时材料处于弹/塑性变形阶段,随后在磨粒的挤压及撕扯作用下,材料内部产生大量微裂纹,微裂纹的合并、连通和扩展最终形成了平行于工件表面的横向裂纹和垂直于工件表面的纵向微裂纹,导致工件材料的脆性断裂去除.

英文摘要：

The conventional finite element method is over-reliance on the mesh dimension, specifically, the mesh distortion is usually serious in the contact area of the abrasive particle and workpiece which makes it more difficult to simulate the formation process of internal cracks in brittle materials. To simulate the lapping process of fused silica optics, FE/SPH model of the machining process for a single abrasive particle was established. Then a new way to simulate the cutting process of brittle materials was provided. The formation process of subsurface crack and the influence of cutting parameters on subsurface damage depths were analyzed. Simulation results show that the brittle material is in the elastic-plastic deformation stage when abrasive particle is just beginning to cut into the workpiece,further amounts of microcracks arise under the extrusion and tear effects of the abrasive particle. The combination and extension of microcracks produced transverse and longitudinal cracks, which are parallel and perpendicular to the workpiece surface, respectively. Consequently, brittle-fracture removal of the workpiece material is completed.