淬火过程应力/应变场有限元模拟关键技术研究

针对淬火过程应力/应变场的特点,给出了淬火过程弹性区、塑性区的应力应变关系。根据淬火过程热物性参数及组织转变的特点,给出了处于弹性区和塑性区的单元应变增量表达式,及热应变、相变应变、相变塑性等初应变的计算方法。给出了热弹塑性问题有限元变分方程、变分方程右端列向量的计算方法及适用于淬火过程的迭代收敛准则。编写了淬火过程有限元模拟程序,并用该程序模拟了圆柱试样的淬火过程,将模拟所得结果与实验结果相比较可以看出,模拟结果与实验结果吻合较好。

Research on the key technologies of evaluating stress-strain using FEM during the quenching process

Quenching technology is a high non-linear process with the effect of temperature, phase-transformation and stress/ strain each other. According to the characters of stress-strain fields in the process of quenching, the stress-strain relationships of elastic region and plastic region of quenching part are given in the paper. The total element strain rate formulations of elastic region and plastic region are given, the methods of computing initial strains, such as thermal strain, strain due to phase transformation and phase-transformation plasticity, are presented. FEM variational equation of elastic-plastic problem, the method of computing right row vector and convergence regulation applying to quenching process are presented in the paper. A finite element simulating software for evaluating the stress/strain is developed in this paper, and the quenching process of cylinder sample is simulated. The comparisons show that the evaluating results are consistent with the experiment results.