磨粒磨损的接触分析

Contact Analysis of Abrasive Wear

磨粒磨损作为磨损的主要类型之一,影响机械使用寿命。针对犁沟磨损机制,采用球形磨粒模型和分形磨粒模型,对于磨粒磨损的压入、滑动和压碎3个过程,利用有限元软件ANSYS,分析磨粒与磨损表面接触区的Mises应力和剪应力分布以及应力随表面深度的变化情况,并对2种模型的分析结果进行对比。研究结果表明,球形磨粒模型中,磨粒与表面接触处的Mises应力和剪应力分布比较分散,且应力峰值较小,在相同材料和压力下磨粒和表面均未压碎;然而分形磨粒模型中,磨粒与表面接触处的Mises应力和剪应力分布比较集中,且应力峰值较大,磨粒和表面均压碎。2种模型中,采用分形方法构造的分形磨粒形状与实际情况中的磨粒形状更加相似。

Abrasive wear is a major mechanism that affects the service lives of machines. For the ploughing wear mecha- nism, the wear debris was modeled respectively with spherical and the likely fractal debris, and abrasive wear was divided into three processes：pressing, sliding and crushing. With the finite element software ANSYS, the Mises stress and shear stress distribution and their changes with the depth of the surface increasing were studied, and analysis results of the two models were compared.The results demonstrate that, in the spherical model ,the distribution of Mises stress and shear stress at the contact area between the debris and the contact surface is more dispersed, and the stress peak value is smaller, and neither the abrasive debris nor the contact surface is crushed;however,in the fractal model,the distribution of Mises stress and shear stress at the contact area between the debris and the contact surface is more concentrated, and the corresponding stress peak value is higher, and the debris and the contact surface are both crushed.For the two models,the fractal shape of abrasive particles constructed with fractal method is more similar to the actual shape of the wear debris.