(1. 大連理工大學 汽車工程學院，大連 116024；
2. 大連理工大學 工程力學系，大連 116024；
3. 吉林大學 材料科學與工程學院，長春 130022)
摘 要: 基于GTN損傷模型，采用實驗與有限元仿真相結(jié)合的方式對高強度7075-T6鋁合金在溫成形HFQ工藝過程中的損傷演化進行研究。通過掃描電鏡觀測得鋁合金板材在變形中的損傷演化符合孔洞長大、形核、聚合和最終斷裂的規(guī)律；采用中心復合試驗設(shè)計法構(gòu)造拉伸曲線關(guān)鍵變量關(guān)于GTN損傷參數(shù)的響應曲面模型，進而結(jié)合遺傳算法確定鋁合金板材的損傷參數(shù)；通過有限元軟件ABAQUS仿真預測不同溫度下鋁合金方盒拉深過程中的損傷分布情況。結(jié)果表明:提高成形溫度可使得鋁合金板材的成形性得到有效改善，實驗觀測的板材開裂行為和開裂位置與損傷預測結(jié)果相一致，證明了GTN損傷模型在鋁合金溫沖壓成形性仿真分析中的適用性。
關(guān)鍵字: 7075-T6鋁合金；溫成形；GTN損傷模型；損傷識別；數(shù)值模擬
（1. School of Automotive Engineering, Dalian University of Technology, Dalian 116024, China;
2. Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China;
3. College of Materials Science and Engineering, Jilin University, Changchun 130022, China）
Abstract:Based on GTN damage model, both experimental and FEM method were used to research the damage evolution of high strength 7075-T6 aluminum alloy during warm forming HFQ process. Through the microstructure observation, the damage evolution within tested material corresponds to the process of void growth, nucleation, coalescence and subsequent fracture. The response surface model between GTN parameters and critical points of tensile curve was built based on central composite design. Then, the genetic algorithm was adopted to determine damage parameters of this aluminum alloy. After that, damage distribution during square cup deep-drawing process was predicted by finite element software ABAQUS. The results show that the formability of aluminum alloy can be improved significantly with the temperature increasing. The fracture behavior and location obtained by experiment consist with those by prediction. So, it demonstrates the applicability of GTN damage model in analyzing formability of aluminum alloy during warm forming.
Key words: 7075-T6 aluminum alloy; warm forming; GTN damage model; damage identification; numerical simulation
