Failure analysis and damage modeling of precipitate strengthened Cu–Ni–Si alloy under fatigue loading

Abstract

Failure analysis and damage evolution in precipitation hardened Cu-2.5Ni-0.6Si alloy are investigated in this study. Firstly, experimental fatigue tests were performed to determine the S-N curve of the material. Then, based on the results of fatigue tests, we have modeled the damage using four linear and cumulative models. The intersection of damage-reliability curves allowed to define three stages of damage during the life cycle for various loading levels. The life fraction βp reveals the stage of slow crack propagation where a preventive action must be adopted to ensure the proper functioning of the structure. The life fraction βc corresponds to the stage of sudden crack propagation when the damage becomes uncontrollable.