Comparison in Fatigue Crack Growth Rate between In-Plane Bending and Cyclic Torsion

Abstract

Fatigue crack growth under multiaxial loading is of importance in engineering practice. In order to examine the effect of stress biaxiality on the fatigue crack growth rate, torsional (biaxial) and uniaxial bending fatigue tests were carried out in this study by using a tough-pitch copper. The experimental results showed that in the case of torsional fatigue the compressive non-singular stress acting parallel to the direction of the initial cracked plane considerably accelerated the mode I crack growth rate in comparison with the result of the uniaxial bending fatigue test.