CRACK CLOSURE AT VARIABLE AMPLITUDE FATIGUE - A SIMPLIFIED APPROACH

摘要

A procedure for fatigue life prediction is presented using the Palmgren-Miner law for damage accumulation. Sequential effects are taken into account by estimating an approximate constant closure level throughout the whole fatigue life. This estimate is based on the basic assumption that the closure dynamics is related to the size of the plastic zone created by high level crossings as compared to the mean growth rate.