(重慶大學 材料科學與工程學院，重慶 400044)
摘 要: 對子彈鉛套成形過程中的破裂缺陷進行預測。采用單向拉伸實驗獲得純鉛真實應力-應變數(shù)據(jù)，選取應變0.006≤ε≤0.2范圍內(nèi)的數(shù)據(jù)進行擬合和外延處理獲得材料無損傷的本構(gòu)模型。結(jié)合掃描電鏡分析法和基于響應面的有限元反求法獲得純鉛的GTN細觀損傷模型參數(shù)，對比分析單向拉伸中模擬與實驗獲得的載荷-位移曲線和鉛材料孔洞體積分數(shù)，驗證了所建立的純鉛GTN細觀損傷模型的準確性。基于ABAQUS模擬仿真平臺，耦合所建立的GTN損傷模型對鉛套成形過程中的破裂行為進行仿真預測，并開展了鉛套反擠壓和變薄拉深成形實驗。結(jié)果表明：實驗結(jié)果與基于GTN損傷模型的仿真結(jié)果匹配良好；對鉛套成形缺陷的準確預測是鉛套成形優(yōu)化的重要基礎(chǔ)。
關(guān)鍵字: 鉛套成形；GTN細觀損傷模型；響應面法；掃描電鏡；破裂預測
（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
