Fatigue of Spring Materials

This chapter explains the common methods for considering stress amplitude in the fatigue life of springs. The fatigue of spring materials under fully reversed uniaxial loading is reviewed. Two different fatigue life estimation methods are briefly discussed. The first method implements the stress-life and strain-life procedures. The second method describes fatigue crack growth (FCG) per cycle. Two analogous unifications of the FCG functions are proposed. The expressions for the spring length over the number of cycles are derived. This chapter is the first section of the final part, which studies the life cycle of elastic elements.