|Title:||Simulation of crack propagation of a skidded rail wheel using Extended Finite Element Method (XFEM)|
|???metadata.dc.contributor.*???:||Daniel Tilahun (PhD)|
|Keywords:||Crack propagation;Elastic-Plastic;Frictional Heating;Hertz contact Theory;Extended finite Element Method (XFEM);Maximum principal stress;Equivalent plastic strain (PEEQ)|
|Abstract:||In this thesis work, an investigation of a crack growth pattern due to the additional effect of the frictional heat induced on the static mechanical full load due to skidding of a wheel on a rail is conducted using an Extended Finite Element Method (XFEM). The contact parameters are determined using Hertz contact theory. The assumption of the elliptical contact pressure distribution is linearized to give a simple rectangular pressure distribution. The contact elliptical area is also assumed to be as an equivalent rectangular area. The frictional heating case is considered at the maximum sliding velocity having in mind the full loading spectrum of the wheel on the entire journey. The Material of the wheel is assumed to be an isotropic hardened Elastic-plastic material and the damage initiation criterion selected is the maximum principal stress. An energy based damage evolution is selected for the crack growth simulation. The crack Extension pattern with respect to the crack tip maximum principal stress and Equivalent plastic strain (PEEQ) are plotted for both case scenarios and it is can then be inferred that the as the crack length increases the crack tip stress and plastic strain also increases therefore the wheel will lose integrity for further successive damage.|
|Appears in Collections:||Railway Engineering|
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