冲击加载下42CrMo钢的动态力学性能及其本构关系

Mechanical Properties and Constitutive Relation for 42CrMo Steel under Impact Load

车轴作为高速列车走行部中的重要部件,不可避免地需承受冲击载荷作用。为研究车轴用42CrMo钢的冲击动态力学性能,对其进行了应变率0.001~4 163s-1范围内的压缩实验,结果显示42CrMo钢在高应变率下表现出明显的应变率效应,存在应变硬化以及一定的热软化效应。根据实验结果对Johnson-Cook模型中应变项和应变率项解耦,并引入绝热温升,得到改进的Johnson-Cook模型,改进Johnson-Cook模型能够较好地描述42CrMo钢的动态力学特性,为实际工程结构力学分析提供了参考。

As an important part of high-speed trains,the axle has to withstand complex loads, especially the shock load in the train＇s operating conditions. To study the dynamic mechanical properties of the 42CrMo steel used in axle production, quasi-static and dynamic compression experiments of 42CrMo steel were conducted at strain rates from 0.001 s-1 to 4 163 s^-1. The results of these experiments show that the 42CrMo steel has an effect of strain rate,strain hardening and thermal softening at high strain rate. Based on the experimental results, we improved the Johnson-Cook model by decoupling the terms of the strain and the strain rate,and also by considering the adiabatic temperature rise. The improved Johnson-Cook model has proved to be capable of describing the dynamic mechanical properties of the 42CrMo steel well and providing reference for practical engineering structural mechanics analysis.