Generalization of unified transformation-plasticity constitutive equation with identified material parameters and the application to metallo-thermo-mechanical simulation.

该项目的动机，提出了一个模型，评估相变塑性，TP，系数的数值计算，因为识别的系数，到目前为止，需要复杂和耗时的实验。提出了一个由母相和新相组成的并联双杆模型：在冷却相变过程中，热膨胀系数较大的母相产生拉应力，而热膨胀系数较小的新相产生压应力。甚至低于屈服应力的拉伸外应力被母相中的初始拉伸应力加速，容易达到屈服，随后发生塑性变形。采用简单的热弹塑性理论，利用表征应力-应变关系的材料参数和表征材料相变动力学的材料参数，数值计算了应力和应变随外加应力大小变化的速率和当前值。将外加应力作用下的诱导应变与零应力作用下的诱导应变之差称为TP应变，TP系数由TP应变除以外加应力得到。

The project motivates to propose a model of evaluating the transformation plasticity, TP, coefficient by numerical calculation since identification of the coefficient so far needs complicated and time consuming experiments. A parallely connected two bar model consisted of mother and new phases is proposed : Tensile stress occurs in mother phase with larger thermal expansion coefficient in the course of cooling phase transformation, while compressive stress takes place in new phase with smaller coefficient in new phase. A tensile external stress even lower than yield stress is accelerated by the initial tensile stress in mother phase easily reaches yielding followed by plastic deformation. Simple thermo-elastic-plastic theory is employed to numerically calculate the rate and the current value of stress and strain in both phases depending on the amount of externally applied stress by use of material parameters for stress-strain relation and phase transformation kinetics characterized to material focused. Deviation of induced strain subjected to external stress from that of zero stress is now regarded as TP strain, and the TP coefficient is obtained by the TP strain divided by the external stress.