Fatigue Assessment and Fatigue Life Calculation of Metals on the Basis of Mechanical Hysteresis, Temperature, and Resistance Data

Abstract

Abstract Mechanical stress-strain hysteresis, temperature, and electrical resistance measurements were performed for the microstructurerelated characterisation of the cyclic deformation behaviour and for the fatigue life calculation of metals. The electrical resistance is strongly influenced by the defect density, and allows the detection of a proceeding fatigue damage under cyclic loading and during load-free inspection intervals as well. On the basis of comprehensive mechanical, thermal, and electrical fatigue data the physically based fatigue life calculation “Phybal” was developed at the Institute of Materials Science and Engineering at the University of Kaiserslautern. This method requires only one load increase test and two constant amplitude tests for a fast and nevertheless precise calculation of S-N (Woehler) curves, leading to a significant reduction in experimental time and costs.