(1. 燕山大學(xué) 先進鍛壓成形技術(shù)與科學(xué)教育部重點實驗室，秦皇島 066004；
2. 燕山大學(xué) 河北省特種運載裝備重點實驗室，秦皇島 066004)
摘 要: 為確定符合高強鋁板變形規(guī)律的韌性斷裂準則的斷裂參數(shù)，設(shè)計了10種不同形狀和缺口的拉伸試樣，分別采用積分式方程組法、解析式方程組法和曲面擬合法求解韌性斷裂準則的多組斷裂參數(shù)。通過分析統(tǒng)計理論斷裂應(yīng)變與試驗斷裂應(yīng)變之間的相對誤差評價了斷裂參數(shù)的預(yù)測精度。結(jié)果表明：采用積分式方程組法和解析式方程組法依據(jù)誤差分析分別篩選出的兩組試樣組合方案的預(yù)測精度均較好(誤差均值小于30%)，而曲面擬合法由于樣本數(shù)據(jù)較少預(yù)測誤差較大。根據(jù)積分式方程組法、解析式方程組法和曲面擬合法求解的最優(yōu)斷裂參數(shù)，應(yīng)用Lou-Huh 2013準則繪制7075-T6高強鋁板成形極限圖，并采用半球形剛模脹形試驗進行驗證。驗證結(jié)果表明：積分式和解析式方程組法預(yù)測7075-T6高強鋁板破裂失穩(wěn)偏于安全，這與參數(shù)求解時斷裂起始點的選取偏于安全有關(guān)。
關(guān)鍵字: 韌性斷裂準則；斷裂參數(shù)；誤差分析；7075鋁合金；成形極限圖
（1. Key Laboratory of Advanced Forging and Stamping Technology and Science, Ministry of Education, Yanshan University, Qinhuangdao 066004, China;
2. Hebei Key Laboratory of Special Delivery Equipment, Yanshan University, Qinhuangdao 066004, China）
Abstract:In order to obtain the fracture parameters of the ductile fracture criterion in accordance with the deformation regularity of high-strength aluminum sheet, ten tensile specimens with different shapes and notches were designed, and simultaneously the integral equations method, the analytic equations method and surface fitting method were used to calculate the fracture parameters of the ductile fracture criterion. The prediction error between the theoretical fracture strain and the experimental fracture strain was analyzed to evaluate the prediction accuracy of the fracture parameters. The results show that two specimen options are respectively selected from the integral equations method and the analytical equations method have better prediction accuracy with mean error of less than 30%. The surface fitting method has large prediction error because the data of tensile specimen is less. Based on the optimal fracture parameters, calculated by the integral equations method, the analytical equations method and surface fitting method, the forming limit diagrams of AA7075-T6 sheet are drawn by Lou-Huh 2013 criterion and are verified by punch-sketch test. The verification result shows that it is safe when the integral equations method and analytic equations method were used to predict the fracture problem of AA7075-T6 sheet. This phenomenon is related to the determination of the fracture initiate point during fracture parameters calculation process.
Key words: ductile fracture criterion; fracture parameter; error analysis; 7075 aluminum alloy; forming limit diagram
