(重庆大学 材料科学与工程学院，重庆 400044)
摘 要: 对子弹铅套成形过程中的破裂缺陷进行预测。采用单向拉伸实验获得纯铅真实应力-应变数据，选取应变0.006≤ε≤0.2范围内的数据进行拟合和外延处理获得材料无损伤的本构模型。结合扫描电镜分析法和基于响应面的有限元反求法获得纯铅的GTN细观损伤模型参数，对比分析单向拉伸中模拟与实验获得的载荷-位移曲线和铅材料孔洞体积分数，验证了所建立的纯铅GTN细观损伤模型的准确性。基于ABAQUS模拟仿真平台，耦合所建立的GTN损伤模型对铅套成形过程中的破裂行为进行仿真预测，并开展了铅套反挤压和变薄拉深成形实验。结果表明：实验结果与基于GTN损伤模型的仿真结果匹配良好；对铅套成形缺陷的准确预测是铅套成形优化的重要基础。
关键字: 铅套成形；GTN细观损伤模型；响应面法；扫描电镜；破裂预测
（Chongqing University, College of Materials Science and Engineering, Chongqing 400044, China）
Abstract:The fracture prediction in the forming process of bullet lead sleeve was studied. The true stress-strain data of pure lead were obtained by uniaxial tensile test, in which the strain range of 0.006≤ε≤0.2 was selected for fitting and extrapolating to obtain the damage free constitutive relationship. The parameters of the GTN micro-damage model of pure lead were acquired by means of scanning electron microscopy analysis and inverse finite element simulation based on response surface method. The load displacement curve and void volume fraction of lead material obtained by simulation and experiment in uniaxial tension were compared and analyzed, which verified the accuracy of the parameters in the GTN model of pure lead. Based on ABAQUS simulation platform, coupled with the GTN damage model, the fracture behavior of lead sleeve during forming process was simulated and predicted. The experiments of back extrusion and thinning deep drawing for lead sleeve were carried out. The results show that the experimental results match well with the simulation results based on GTN damage model. The accurate prediction of forming defects of lead sleeve is an important basis for forming optimization.
Key words: formation of lead sleeve; GTN micro-damage model; response surface method; scanning electron microscope; fracture prediction
