Cracking analysis of bolster cover plate in C70 freight wagons

After two year service, cracks are frequently found at the under surface of the bolster cover plate which seriously affect the reliability of the freight wagon. The stress state of bolster cover plate should be analyzed on the basis of preliminary analysis, residual stress test, static stress test and dynamic stress test. The scope of this paper is to study the causes and characteristics of the cracks, which performed by fracture mechanics analysis and FEM analysis as well as stress tests. The research results have then been used for predicting the crack initiation life and propagation life.