Study On Erosion Model And Damage Mechanism Of Elastic Coatings

Erosion is a common damage form in the field of aviation,and the existence of elastic coating plays a better role in the protection of aircraft parts.Erosion particles are generally small and the damage for the elastic coating is not obvious,especially the layer damage of the coating,which happens internally and is difficult to detect.Continuous erosion of the coating/matrix structure with delamination will result in peeling of the coating,which will lead to direct damage of external particles for the matrix material and greatly reduce the service life of aircraft parts.Therefore,it is very important to think about delamination in the erosion damage and further study the failure mechanism of the elastic coating.The cohesive element is suitable for the separation damage of materials.Cohesive element is applied to the erosion analysis of coating/matrix model,and established erosion models under the different conditions.In the multi-particle model,the internal mechanisms of different erosion densities,different erosion distances and repeated erosion accumulation of the elastic coating damage are studied.In the singleparticle erosion model,the effects of different velocities,angles and particle radius on the elastic coating are discussed.Conclusion follows as:(1)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 is,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.(2)The failure modes of elastic coating mainly include pits,furrows and delamination.Without delamination,the furrow in the same direction as particle erosion is more possible to occur under the low erosion angle.In the high erosion angle,it is easy to form a pit.The vertical component of velocity is the main cause of delamination damage,and the area of erosion contact will affect the area of delamination.Plastic dissipation energy is the more forms in erosion process.