Virtual testing of plasticity effects on fatigue crack initiation

The paper draws attention to the comparison of materials defined by different constitutive laws, including elastic and modified elastic-plastic laws of aluminum alloy AlSi8(Cu3). These materials have been virtually tested under fatigue conditions by applying a microstructurally-based fatigue crack initiation modelling approach. The main focus is to show the influence of plastic properties, i.e. hardening, on the fatigue initiation (S-N-ini) life curves of the considered materials. By adding the plastic aspect to the materials' constitutive laws, it could be shown that certain effects on the fatigue limit in the S-N-ini diagram can be achieved.