Fatigue Life And Reliability Analysis Of NO.17 Coupler And Coupler Yoke

The starting of Da-Qin Railway 20,000 tons coal trains makes important sense in coal transportation and economic development, but also causes great damage to the coupler and the coupler yoke, cracks appear universal in a short time, which cause great threaten to safe driving. So it is significant to study the fatigue life of the coupler and the coupler yoke.The study object of this paper is type NO.17 coupler and coupler yoke and this paper analyzes the static strength of them. According to the AAR spectrum and test spectrum of Da-Qin Railway, the crack initiation life of them is computed by using local stress-strain method, the crack propagation life is estimated using fracture mechanics method based on the two spectra above, and the reliability of crack propagation life of the coupler and the coupler yoke is analyzed with Monte Carlo method used based on the two spectra above.The paper contains the following contents:1. Establish the 3D model refer to the 2D drawing using SOLIDWORKS, and analyze the static strength of the coupler and the coupler yoke using ABAQUS software. The result shows that critical sites endure bigger stress and actual crack and fracture appear at the same points.2. Get the steady-state stress-strain curve of grade E steel by test. According to the AAR spectrum and test spectrum of Da-Qin Railway, the crack initiation life is estimated using local stress-strain method and comparison of computed results and actual life is processed.3. Compute the stress intensity factors based on 1/4 displacement method in finite element method, calculate and analyze the crack propagation life of coupler and coupler yoke using Paris formula.4. Analyze the reliability of the crack propagation life of the coupler and the coupler yoke based on Monte Carlo method; compute the failure probability of the coupler and the coupler yoke in different life span.