Determining permissible stresses in simple cyclic loading

Cyclic loading stress is examined for a limiting-state diagram which characterizes the fatigue resistance, the permissible stresses, the cyclic cracking resistance, and the limiting fatigue crack size. It has been found for 09G2 steel that the limiting crack size is dependent on the stress cycle asymmetry if the permissible stresses are determined for a given strength margin coefficient. One can construct a permissible-stress diagram for a given crack size. In that case, the strength margin coefficient is dependent on the stress cycle asymmetry, which enables one to make better use of the material. Translated from Problemy Prochnosti, No. 1, pp. 97–102, January–February, 1997.