15-5PH沉淀硬化不锈钢的塑性本构建模

On Constitutive Mold of 15-5PH Precipitate Hardened Stainless Steel

材料的塑性本构模型描述了材料的流动应力与塑性应变、应变率和温度等因素之间的数学关系,是机械加工有限元仿真的基础。针对航空航天、核电及海洋工程等领域关重零件制造中广为应用的15-5PH沉淀硬化不锈钢开展了准静态压缩试验与SHPB试验,基于材料力学特性的温度相关性建立了J-C本构修正模型的数学形式,并采用多目标优化的本构参数拟合方法,确定了J-C本构修正模型的参数。基于J-C本构修正模型的SHPB试验仿真,获得的真实应力—应变数据曲线与SHPB试验数据曲线具有较好的一致性,弥补了经典J-C本构模型对15-5PH沉淀硬化不锈钢高温动态力学特性数学描述的不足,从而有效将基于J-C本构修正模型的SHPB试验仿真的应力预测误差控制在10%以内。

The plastic constitutive model of materials describes the mathematical relationship between material flow stress and plastic strain,strain rate,temperature and other factors,which is the basis of finite element simulation of machining.In this paper,the quasi-static compression test and Split Hopkinson Press Bar(SHPB)test of 15-5PH precipitation hardened stainless steel,which is widely used in the manufacture of critical parts in aerospace,nuclear power and Marine engineering,are carried out.The mathematical form of the J-C(Johnson-Cook)constitutive modification model is established based on the temperature dependence of mechanical properties of materials,and the parameters of the J-C constitutive correction model are determined by using the constitutive parameter fitting method of multi-objective optimization.The real stress-strain data curve obtained by SHPB test simulation based on J-C constitutive modification model is in good agreement with the SHPB test data curve,which makes up for the deficiency of mathematical description of high temperature dynamic mechanical properties of 15-5PH precipitated hardening stainless steel by classical J-C constitutive model.Thus,the stress prediction error of SHPB test simulation based on J-C constitutive model is controlled within 10%effectively.