In the present study, the fatigue tests under tension-tension variable amplitude loading (VAL) are carried out on 45 carbon steel, which is similar to the AISI 1045 steel, to investigate the probability distribution of fatigue life under VAL and investigate the validity of a new simulation model proposed in the paper for the fatigue test and the probability distribution of fatigue life under VAL.

The fatigue life with given survivability under variable amplitude loading is predicted,and checked by simulating test using Monte Carlo method.

By using constant amplitude loading and highlow cycle complex loading, contrast test research for crack growth rate was conducted for ductile cast Iron.

The author investigates the effect of mean stress and stress's amplitude with the non symmetry low cycle fatigue (LCF) experiment of two kinds of PD3 rail steel (hot rolling and off line heat treatment) produced by PanZhiHua steel company.

The effect of small loads superposed upon principal cyclic load ?P on the fatigue crack growth rate da/dN has been studied for A537 steel in 3.

The influence of small loads superposed upon principal cyclic load △P on the fatigue crack growth rate da/ dN has been studied for the single edge notched plate specimens of A537 steel, and the crack closure behaviour has been investgated by measurement of crack opening displacement with speckle interferometry(SPI) technique.