固体颗粒冲蚀磨损模型的建立及有限元分析

Modeling and Analysis of Solid Particle Erosion Process Based on Finite Element Method

着眼于固体颗粒冲击壁面的微观动态过程,建立了基于有限元(FEM)方法的颗粒冲蚀数值计算模型,模型中充分考虑了颗粒形状、冲击参数、材料特性等因素以及多颗粒重合打击的影响,通过引入弹塑性本构模型和失效模型描述金属材料的变形及失效行为,研究了冲蚀因素对冲蚀速率及表面变形特征的影响规律。结果表明,模型能够完整的展示冲击的动态过程,预测了颗粒冲蚀金属材料表面所造成的变形及失效破坏现象,多颗粒冲击造成材料表面的累计破坏使冲蚀量增大,冲蚀速率逐渐趋于稳定。为使模型能够合理的预测高应变率条件下材料变形,修正了本构模型中的应变率项,修正后的模型计算得到的冲蚀速率随冲击角的变化规律与工程实际更加符合,为今后微观颗粒冲蚀模型的建立及应用打下了理论基础。

In this paper, based on the finite element （FEM） method, the numerical calculation model of particle erosion is established based on the micro dynamic process of the solid particles impacting on the material surface. The model fully considers the particle shape, impact parameters, material properties and other factors. By introducing elastic - plastic constitutive models and failure model to describe the deformation and failure behavior of metal materials, effects of erosion factors on erosion loss and surface deformation features were investigated. The results show that the model can properly demonstrate the dynamic progress of impact, and the deformation and failure of the particles on the surface of the metal materials were predicted. Besides, the cumulative damage of the materials surface caused by impacts of multiple particles can make erosion quantity increases, while the erosion rate tends to be constant. In order to predict the deformation of materials reasonably under high strain rate and based on the model, the strain rate term in the constitutive model was modified, and the change rule of the erosion rate with the impact angle calculated by the modified model is in line with the engineering practice, which lays a theoretical foundation for the establishment and application of micro particle erosion model in the future.