Resolution of the threshold fracture energy paradox for solid particle erosion

摘要

Previous models of a single erosion impact, for a rigid axisymmetric indenter defined by the shape function z = B(1-lambda)r(lambda), have shown that a critical shape parameter lambda* = 5.5 exists which determines the behaviour of the threshold fracture energy. However, repeated investigations into this parameter have found no physical explanation for its value. Again utilising the notion of incubation time prior to fracture, this paper attempts to provide a physical explanation of this phenomena by introducing a supersonic stage into the model. The final scheme allows for the effect of waves along the indenters contact area to be taken into account. The effect of this physical characteristic of the impact on the threshold fracture energy and critical shape parameter lambda* are investigated and discussed.