Analytical and Numerical Crack Growth Analysis of 1:3 Scaled Railway Axle Specimens

Metals

Martin Leitner¹  David Simunek¹  Reinhard Pippan²  Jürgen Maierhofer³  Hans-Peter Gänser³ 

[1] Chair of Mechanical Engineering, Department Product Engineering, Montanuniversität Leoben, 8700 Leoben, Austria;Erich Schmid Institute of Materials Science, 8700 Leoben, Austria;Materials Center Leoben Forschung GmbH, 8700 Leoben, Austria;

关键词: fatigue crack growth;    railway axle;    semi-elliptical crack;    residual stresses;   

DOI  :  10.3390/met9020184

来源: DOAJ

【 摘 要 】

This paper deals with experimental fatigue crack propagation in rotating bending loaded round bar specimens as well as an analytical and numerical analysis of the residual lifetime. Constant amplitude (CA) load tests are performed with the surface crack length being evaluated using an optical measurement system. Fracture surfaces are microscopically analyzed to determine crack growth in depth as well as the crack shape. In spite of identical testing conditions, the experimental results show some scatter in residual lifetime, which is mainly caused by different residual stress states. Although X-ray residual stress measurements reveal only minor values, a superposition of the residual stress state with the load-induced stress leads to a significant impact on the residual lifetime calculations, which explains the experimental scatter. Numerical analyses are conducted to consider the residual stress state and their effect on crack propagation by different options. Considering the residual stress distribution in depth within the residual lifetime assessment, the deviation to the most conservative experiment is reduced from +48% to +2%. In conclusion, the results in this paper highlight that it is of utmost importance to consider local residual stress conditions in the course of a crack propagation analysis in order to properly assess the residual lifetime.

【 授权许可】

Unknown