Keywords: fatigue damage, damage accumulation, damage modelling, fatigue failure, metal fatigue, probabilistic modelling, mechanical modelling, simulation, stress cycles, stress-strain hysteresis
A probabilistic mechanical model for simulating fatigue failure in metals – modelling the damage accumulation process
It is demonstrated that analysis of a probabilistic model for simulating the fatigue process in metals previously reported leads to the well-known Palmgren-Miner Law for fatigue damage accumulation. In a paper published in the Journal of Damage Mechanics, a mechanical model was presented that was used to simulate the S-N relations in metal fatigue problems. The simulation is accomplished by a model which is a system containing a number of sliding blocks connected by springs which rupture sequentially during cycles of applied stress. When a sufficiently large number of springs have ruptured, the entire system is presumed to have failed in fatigue. Further work on the model was completed by the authors on the capabilities of the model. The behaviour of the system, when subjected to a number of stress cycles, was investigated by analysing the cycle by cycle accumulation of stress-strain hysteresis. Through simulations, it has been shown that the model can closely portray the linear damage accumulation process as predicted by the Palmgren-Miner Law.