Relative damage stress: Dominant mechanical factor for the failure of soldered joints under temperature cycling

By temperature normalization of the concept of equivalent damage stress pro posed by Lemaitre, a new concept of relative damage stress has been put for ward as the dominant mechanical factor for the failure of soldered joints u nder temperature cycling. Finite element numerical simulation results showe d that the highest value of relative damage stress occurred at the high tem perature hold time during temperature cycling history.