基于逆向拟合法的H13钢J-C本构修正模型

Modified J-C constitutive model of H13 steel based on reverse fitting algorithm

为了简化材料J-C本构模型的建立过程,提出一种基于自定义函数确定本构模型参数的逆向拟合法;通过准静态拉伸实验和霍普金森压杆实验获得H13钢在应变率为1~15000s^-1,温度为298~1073K条件下的真应力-真应变曲线;在总结不同的H13钢J-C本构模型并确定各材料参数范围的基础上,利用J-C本构函数对真应力-真应变曲线进行自定义函数逆向拟合,从而获得H13钢J-C本构模型在不同条件下的材料参数,并进一步建立材料参数关于温度和应变率的关系函数,确定H13钢在大应变率和高温条件下的J-C本构模型。研究结果表明:本文建立的修正型J-C本构模型能够真实地反映H13钢的流变行为。

To simplify the establishment of J-C constitutive model of H13 steel, a reverse fitting algorithm based on custom function was proposed for determining the material parameters of constitutive model. Firstly, the true stress-true strain curves of H13 steel at strain rates of 1-15 000 s^-1 and temperatures of 298-1 073 K were obtained through quasistatic tensile tests and Hopkinson pressure bar tests. Secondly, on the basis of summarizing different J-C constitutive models of H13 steel and determining the range of material parameters, the true stress-true strain curves were inversely fitted by the user-defined function, so as to obtain the material parameters of J-C constitutive equation of H13 steel under different conditions. Finally, the function of material parameters with respect to temperature and strain rate was established, and J-C constitutive model of H13 steel in condition of large strain rate and high temperature range was determined. The results show that the flow behavior of H13 steel is effectively reflected by the proposed modified J-C constitutive model.