Fatigue life calculation of metallic materials

In stress-controlled load increase and single step tests besides the plastic strain amplitude the changes of the temperature and the electrical resistance caused by cyclic plastic deformation were measured. Temperature and resistance measurements don't require a defined gage length and can be applied also on components even under service loading to ensure economic and safe operation conditions. On the basis of Morrow and Basquin equations a physically based fatigue life calculation "PHYBAL" was developed. This new short-time procedure allows a rapid and precise calculation of Woehler curves with data of one load increase and two single step tests.