单球撞击纯钛中的宏观和微观残余应力

Macroscopic and microscopic residual stress in single shot impacted pure titanium

摘要:

采用有限元方法和弹塑性自洽模型模拟纯钛在单个钢球以不同尺寸和速度撞击时的力学响应，计算了宏观和微观残余应力。结果表明随着钢球尺寸和撞击速度的增加，宏观残余压应力增加。宏观残余应力和残余弹性应变具有较好的一致性。微观残余应力分布在一个随深度变化的范围内。在某一深度处微观残余应力的统计分布符合高斯分布，其离散程度由有效塑性应变决定。有效塑性应变随钢球尺寸和撞击速度变化。增加撞击速度和降低钢球尺寸，在某一深度处微观应力分布的标准差增加。

Abstract:

The finite element method (FEM) and elasto-plastic self-consistent (EPSC) method were used to simulate the mechanical response of pure titanium subjected to single steel shot impacting at different shot sizes and velocities. The macroscopic and microscopic residual stresses were calculated. The results indicate that the observed macroscopic residual compressive stress increases with an increase in the shot size and impacting velocity. In addition, the macroscopic residual stress calculations correlate well with the residual elastic strain. The microscopic residual stresses lie within a range that varies with depth. Furthermore, the statistical distribution of the microscopic residual stress agrees well with the Gaussian distribution. Additionally, the dispersion of microscopic residual stresses, determined by the effective plastic deformation, is influenced by the shot size and impacting velocity. With an increase in the impacting velocity and decrease in the shot size, the standard deviation of the microscopic residual stresses at a certain depth increases.