Simulation des Mikrorisswachstums unter Schwingbeanspruchung. Teil 2: Simulationsergebnisse – Einfluss des Spannungszustandes und Reihenfolgeeffekte

Simulation of fatigue micro crack growth. Part 2: Results of simulation – influence of stress state and sequence effects In part one the modelling of micro crack growth due to alternating loading has been presented. Simulation results for tension/compression, torsion and proportional multiaxial loading, the scatter of the simulated lifetimes to a macroscopic crack length of 500 μm as well as the influence of the density of crack seeds and the grain size have been presented. In part two the influence of the stress state under proportional and non‐proportional loading is examined. Additionally the sequence effect of High‐Low and Low‐High as well as consecutive load sequences will be discussed. The comparison of the simulation results to experimental results shows that the influences of multiaxial loading and sequences can be simulated qualitatively correctly. The simplifications of the modelling have been to be considered. If the length of the maximum crack is interpreted as a measure of the damage, it can be concluded that the damage accumulation is non linear and non continuous. The main proportion of lifetime from the crack seed to the macro crack is contributed in the phase in which the length of the maximum micro crack comes close to the size of the grain size.