X12合金钢高温Normalized Cockcroft&Latham损伤模型及参数反求分析方法

High temperature Normalized Cockcroft&Latham damage model and inverse analysis method of parameter for X12 alloy steel

在Gleeble-1500D热模拟试验机上进行了X12合金钢在温度为900~1150℃、应变速率为0.5 s^(-1)条件下的高温拉伸试验,建立了X12合金钢的Hansel-Spittel本构模型。基于Normalized Cockcroft&Latham(NCL)损伤模型,通过引入该材料临界损伤值与温度的函数关系,建立了X12合金钢的高温损伤模型。将优化方法和有限元相结合,通过反求分析方法得到了该材料的高温损伤模型参数。将所建立的高温损伤模型嵌入到商业有限元软件Forge中,模拟了X12合金钢在温度为900~1150℃、应变速率为0.5 s^(-1)的高温拉伸过程,通过对比模拟得到的断裂位移与试验试样断裂位移得到其最大误差、最小误差和平均误差分别为3.169%、0.480%和1.496%。结果表明,高温NCL损伤模型能够准确预测X12合金钢在高温成形过程中裂纹的产生。

The high-temperature tensile tests of X12 alloy steel at 900-1150℃and strain rate of 0.5 s^(-1)were performed on Gleeble-1500 D thermal simulator,and the Hansel-Spittel constitutive model of X12 alloy steel was established.Based on the Normalized Cockcroft&Latham(NCL)damage model,the high-temperature damage model of X12 alloy steel was established by introducing the function relationship of critical damage value and temperature.The optimization method and finite element were combined to obtain the parameter of hightemperature damage model by inverse analysis method.The established high-temperature damage model was integrated in the commercial finite element software Forge,and the high-temperature tensile processes of X12 alloy steel at 900-1150℃and strain rate of 0.5 s^(-1)were simulated.By comparing the simulated and the tested fracture displacement,the maximum error,the minimum error and the average error of 3.169%,0.480%and 1.496%were obtained,respectively.The results show that the high-temperature NCL damage model can accurately predict the occurrence of cracks in X12 alloy steel during high temperature forming.