基于修正M-K模型的铝合金板材成形极限图预测  

Prediction of forming limit diagram of AA7075-O aluminum alloy sheet based on modified M-K model

作　　者：杨希英[1] 郎利辉[1] 刘康宁[1] 蔡高参[1] 郭禅[1] 

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100191

出　　处：《北京航空航天大学学报》2015年第4期675-679,共5页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金资助项目(50975014);中俄国际合作与交流NSFC-RFBR基金资助项目(51010166)

摘　　要：为准确预测AA7075-O铝合金板材的成形极限,将韧性断裂准则和传统M-K模型相结合,提出一种基于韧性断裂准则的修正M-K模型.利用单向拉伸模拟和试验相结合的方法,提取危险单元的应力应变历史并代入C-L韧性断裂准则中,得到材料常数.基于单向拉伸试验所得成形极限点,通过MATLAB编程得到修正M-K模型的初始厚度不均度.在常温下,以单向拉伸、宽板弯曲、液压胀形试验获得AA7075-O铝合金板材的成形极限曲线,与修正M-K模型和传统M-K模型计算得到的理论成形极限曲线进行对比,验证了修正M-K模型的可行性和准确性.To accurately predict the forming limit diagram of AA7075-O aluminum alloy sheet, a modified M-K model was put forward based on the ductile fracture criterion and the traditional M-K model. By using the method which combined the uniaxial tension simulation with experiment, the history of stress-strain of the dangerous element was substituted into the C-L ductile fracture criterion which was implemented into Abaqus/Explicit to get the material constant. Based on the forming limit data obtained by the uniaxial tensile, the initial thickness imperfection in the modified M-K model was obtained by the method which was programed in MATLAB. At room temperature, the experimental forming limit data of AA7075-O aluminum alloy sheet were tested through the uniaxial tensile, wide plate bending and hydraulic bulging experiments. Meanwhile, the theoretical forming limit curves obtained by the modified M-K model and the traditional M-K model were computed respectively. By comparison, the modified M-K model is proved to be feasible and more accurate.

关 键 词：铝合金板 M-K模型 韧性断裂准则 初始厚度不均度 成形极限图 

分 类 号：V260.1[航空宇航科学与技术—航空宇航制造工程] TG394[金属学及工艺—金属压力加工]