Residual Stress Fields of Precracks and Impact on Fracture Mechanics Properties

Abstract

In fatigue mechanics, lifetime estimations are of major interest and rely on input data from experiments characterizing the fracture resistance of materials. Therefore, such predictions can only be accurate as long as experiments are capable of mimicking reality. Cracks emanating from existing defects are experimentally described using samples possessing an artificial crack. These cracks, however, are predominantly introduced by fatigue loading, which may lead, depending on the applied load scheme, to pronounced residual stress fields ahead of the crack tip and an alteration of the material's behavior. Within this contribution, a simple dislocation analysis is employed to estimate the evolution and size of the residual stress fields introduced by compression–compression loading, and feasible strategies to reduce residual stresses are discussed.