An on-line algorithm of fatigue damage evaluation under multiaxial random loading

An on-line algorithm of fatigue damage evaluation was proposed by modifying Wang-Brown's method under multiaxial random loading. Wang-Brown's method requires rearrangement for the strain history before the counting process starts, which is not suitable for on-line fatigue damage evaluation. So an algorithm based on simple range counting for equivalent relative strain was presented first, and then an on-line algorithm was proposed by defining the fatigue damage in each reversal as rain-flow counting parameter. The proposed on-line algorithm does not require any rearrangement for the strain history and the fatigue damage can be evaluated on-line.