45^#钢的损伤演化方程和层裂准则研究

Research of Damage Evolution Equation and Spallation Criterion of 45^# Steel

通过唯象分析和细观物理统计相结合的方法建立了一种韧性材料的损伤演化方程。在试验结果和内变量理论的基础上得到了45#钢的含损伤热—粘塑性本构关系。用有限差分方法计算了45#钢平板撞击所产生的应力波传播规律、损伤演化规律及层裂进程。通过自由面速度历史的数值模拟,并基于计算结果与试验结果间的最佳一致性,得到了损伤演化方程中的材料参数和极限损伤数值,并以此为依据建立了材料的应力率层裂准则。

A new form of damage evolution equation is presented by the method of phenomenological analysis and microscopic statistics was presented. On the basis of experimental results and internal variables theory, the thermo-viscoplastic constitutive relations for 45^# steel were gotten with the damage been considered. The stress wave propagation rules, damage development and spalling were numerically studied by finite difference method. By the numerical simulations of the free surface velocity histories and based on the best consistence between the computational results and the experimental ones, the material parameters in the damage evolution equation and the spallation criterion were obtained. On the basis of this, the spallation criterion with stress rate form was established.