Relative damage stress and its application in the case of temperature cycling load

Void damage is the main failure characteristics of constrained ductile meta l foil. In order to evaluate the mechanical response of ductile metal under different temperatures, the concept of equivalent damage stress proposed b y Lemaitre is modified by temperature normalization. A new concept of relat ive damage stress is advanced, and in the light of this concept, a reasonab le explanation is given to the thermal fatigue life data of solder joints u nder temperature cycling.