Mechanical durability prediction methods

Simple closed-form analytical expressions are derived to accurately predict the durability (i.e. failure-free operating period or fatigue life) of avionic equipment structural elements as part of the US Air Force Avionics Integrity Program (AVIP) requirements. These expressions are functions of both the quantity of like-structural elements per assembly and quantity of identical assemblies per system for thermal cycling and random vibration environments. Analytical predictions are compared with empirical results for cantilever beams for solder joints on multilayer assemblies containing leadless chip carriers (LCCs)