Ti-6Al-4V钛合金型材电热拉弯成形极限仿真方法  

FEM of forming limit in electric-thermal stretch bending for Ti-6Al-4V titanium alloy profile

作　　者：刘天骄[1] 王永军[2] 杨凯[2] 田鹤飞[1] 孔文超[1] Liu Tianjiao Wang Yongjun Yang Kai Tian Hefei Kong Wenchao(Kunming Shipbuilding Equipment Research Test Center, Kunming 650051, China Shanxi Province Engineering Research Center for Digital Manufacturing Technology, School of Mechanical Engineering, Northwestern Polytechnical University, Xi＇an 710372, China)

机构地区：[1]昆明船舶设备研究试验中心,云南昆明650051 [2]西北工业大学机电学院陕西省数字化制造工程技术研究中心,陕西西安710072

出　　处：《锻压技术》2017年第4期117-122,共6页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51275420);航空科学基金资助项目(2008ZE53037)

摘　　要：针对电加热拉弯成形工艺,建立了电热拉弯过程顺序耦合的数值模拟方法,实现了电热转台式拉弯成形过程的多工序、多场耦合数值模拟。并选用动力显式热-力耦合分析算法,基于J-C断裂准则,建立了电热拉弯成形极限与断裂预测的三维实体模型。通过Ti-6Al-4V钛合金挤压T型材电热拉弯成形试验与仿真预测结果比较发现:电热拉弯成形过程中,材料的失效主要发生在预拉伸和补拉伸阶段,失效原因为拉伸力过大;电热拉弯成形极限的主要影响因素包括加热温度或电流密度、预拉力、补拉伸过程温度或冷却时间和补拉力;预拉伸和补拉伸极限应力的预测相对误差分别为19.7%和19.1%,验证了模型的有效性。For the electric-thermal stretch bending of titanium alloy,a numerical simulation method of sequential coupling of electro-thermal stretch bending process was established,and a multi-process and multi-field coupling numerical simulation process of electro-thermal stretch bending with turntable was realized. Then,the dynamic explicit thermal-mechanical coupling analysis algorithm was selected based on J-C fracture criteria,and a 3D model predicting the forming limit and fracture of electro-thermal stretch bending was built. Comparing the experimental result with simulation result of extrusion T-type profile for Ti-6Al-4V titanium alloy,it is found that the failure of material in the electric-thermal stretch bending process is mainly because of the excessive tensile force on the pre-stretching and post-stretching stages. Therefore,the main factors influencing on the forming limit of electric-thermal stretch bending are the heating temperature or current density,the pre-stretching force,the temperature or cooling time of the post-stretching process and the post-stretching force. Furthermore,the predicted relative errors of limit stress for the pre-stretching and post-tensioning are 19. 7% and 19. 1% respectively,and the effectiveness of model is verified.

关 键 词：TI-6AL-4V钛合金 电热拉弯 成形极限 断裂预测 预拉伸 补拉伸 数值模拟 

分 类 号：V261[航空宇航科学与技术—航空宇航制造工程]