基于内聚力单元的弹性涂层多颗粒冲蚀机理

Multi-particle erosion mechanism of elastic coating based on cohesive element

基于内聚力单元建立了弹性涂层的多颗粒冲蚀模型,分析了涂层和粘结层在冲蚀作用下产生凹坑损伤后的应力分布。讨论了冲蚀密度、颗粒间距、冲蚀次数对涂层和粘结层应力分布的影响。结果表明:在同样凹坑深度损伤下,涂层表面的径向接触应力和粘结层剪切应力的最大值均位于接触区边缘处;颗粒冲蚀密度越大,涂层最大拉应力越小,越不容易产生裂纹,且涂层径向应力的最大值位于最外侧颗粒的接触边缘处;当圆心距大于两颗粒直径之和时,颗粒之间没有相互影响;多次冲蚀产生的应力小于单次冲蚀,裂纹和分层萌生的位置更加接近接触边缘。

A multi-particle erosion model of elastic coating is established based on cohesive elements,the stress distribution on coating and bonding layer with erosion caused pit damage is analyzed.The influence of erosion density,particle distance and erosion times on stress distributionon coating and bonding layer are discussed.Results show that:with the same pit depth,the maximum values of radial contact stress and shear stress of bonding layer locate at the contact edge.The bigger erosion density of particles is,the smaller the maximum tensile stress of the coating becomes,the less likely it is to crack.The maximum radial stress on coating locates at the contact edge of the outermost particles.There is no interaction between particles when the distance between circle centers is bigger than the sum of their diameters.The locations of crack and delamination get closer to the contact edge when the stress produced by repeated erosion is smaller than single erosion.