DP780双相钢剪切修正GTN模型损伤参数确定  

Determination of DP780 Dual Phase Steel Damage Parameters of Shear Modified GTN

作　　者：孙彩凤 李迪[2] 孟令韩 SUN Caifeng;LI Di;MENG Linghan(School of Automotive Engineering,Jiangsu Vocational College of Electronics and Information,Jiangsu Huaian 223003,China;School of Transportation and Vehicle Engineering,Shandong University of Technology,Shandong Zibo 255049,China)

机构地区：[1]江苏电子信息职业学院汽车工程学院,江苏淮安223003 [2]山东理工大学交通与车辆工程学院,山东淄博255049

出　　处：《精密成形工程》2024年第8期190-196,共7页Journal of Netshape Forming Engineering

基　　金：江苏省科技厅产学研项目(BY2022312);淮安市自然科学研究项目(HABZ202123)。

摘　　要：目的为了准确预测DP780双相钢在低应力三轴度时出现的剪切断裂,建立了损伤参数与断裂时载荷和位移的响应面模型,并根据此模型研究损伤参数变化对双相钢剪切断裂的影响,得到最佳损伤参数,以提高预测双相钢发生断裂的精确性。方法以DP780为研究对象,建立了剪切修正GTN模型,以孔洞体积分数fN、孔洞形核时平均应变εN、剪切系数kw为因素,分别以断裂时载荷和位移为响应值,基于试验设计得到对应的响应函数,并在此基础上建立误差评价函数,通过最小二乘法对误差评价函数进行求解得到最佳损伤参数。结果建立了基于断裂载荷和位移的误差评价函数,在此基础上结合试验验证,确定fN=0.025、εN=0.198、kw=2是最佳损伤参数组合。孔洞体积分数和剪切系数对断裂影响较大,随着孔洞体积分数fN的增大,发生断裂时的载荷减小,随着剪切系数kw的增大,发生断裂时的位移缩短。结论基于Abaqus软件,建立了剪切试样有限元模型并对其进行断裂仿真,断裂时平均减薄率为1.4%,与断裂试验结果吻合,表明了获得的损伤参数的准确性,为双相钢在车身结构件中的生产应用提供理论依据。The work aims to establish a response surface model between damage parameters and load or displacement at fracture study the influence of damage parameters on the shear fracture to obtain the best damage parameters and improve the accuracy of fracture predicting,so as to predict the shear fracture of DP780 dual phase steel at low stress triaxial degree.With DP780 as the research object,with void volume fraction fN,average strainεN,shearing factor kw as factors,and with load-displacement at fracture as the response value,and based on the experimental design,the corresponding response function was obtained.On this basis,the error evaluation function was established,and the optimal damage parameter was obtained by solving the error evaluation function by the least square method.The error evaluation function based on fracture load and dis-placement was established,which fN=0.025,εN=0.198,kw=2 was the best combination of damage parameters.Void volume frac-tion and shearing factor had the greatest influence on fracture.With the increase of fN,the load at fracture decreased,the dis-placement of fracture decreased with the increase of shearing factor kw.Based on Abaqus software,the finite element model of shear sample is established to simulate its fracture.The average thinning rate at fracture is 1.4%,which is consistent with the fracture test results.The accuracy of damage parameters is demonstrated,and provides a theoretical basis for the application of dual phase in the body structural parts.

关 键 词：双相钢 剪切修正GTN 损伤参数 断裂失效 

分 类 号：TG386.3[金属学及工艺—金属压力加工]