HIGH-CYCLE FATIGUE BEHAVIOUR OF SPHEROIDAL GRAPHITE CAST IRON

An expression for the cumulative failure probability of a structure is proposed for cyclic loading conditions. This expression is dependent on an initial flaw distribution and a microcrack propagation law. Two sets of experiments were carried out on specimens made of spheroidal graphite cast iron. These specimens are tested under cyclic tension with two different load ratios. The initial flaw distribution is experimentally identified from microscopic observations. The crack propagation law parameters are identified from experimental results obtained with a load ratio R = 0.1. The expression for the failure probability is then used to predict experimental data obtained with a load ratio R = −1.