旋转超声加工陶瓷过程中崩边的有限元分析及实验验证

摘要

崩边现象在旋转超声加工陶瓷材料的过程中较常见，崩边会导致工件的尺寸精度降低，甚至会影响工件形貌的完整性。通过建立二维有限元分析模型，研究了预紧力、支撑长度和材料类型等加工参数对崩边发生区域中最大主应力的影响。并利用扩展有限元理论对旋转超声加工中产生的裂纹形貌进行了预测。在此基础上，提出了一种全支撑装夹模式，能极大地减小崩边尺寸，甚至避免崩边现象的发生，仿真结果得到了实验验证。此外，通过扩展有限元理论还得到了裂纹扩展过程中的趋势。%Edge chipping is a common problem in rotary ultrasonic machining (RUM) of ceramic materials. It leads to reduction of the dimension precision of the work piece and even affects the integrity of the work piece pattern. This paper established a two-dimensional finite element analysis mode to study the effects of preload,supporting length and different kinds of materials on the maximum principal stress in the region where the edge chipping occurs. The theory of extended finite element (XFEM) is used to predict the crack growth process in RUM. On this basis ,a full-supporting mode which can greatly reduce the chipping size even avoid edge chipping is put forward. And crack propagation angle during the crack propagating is achieved by using XFEM.