Calculation of elastic-plastic strain ranges for fatigue analysis based on linear elastic stresses Original Research Article

Fatigue analysis requires that the maximum strain ranges be known. These strain ranges are generally computed from linear elastic analysis. The elastic strain ranges are enhanced by a factor Ke to obtain the total elastic-plastic strain range. The reliability of the fatigue analysis depends on the quality of this factor. Formulae for calculating the Ke factor are proposed. A beam is introduced as a computational model for determining the elastic-plastic strains. The beam is loaded by the elastic stresses of the real structure. The elastic-plastic strains of the beam are compared with the beamʹs elastic strains. This comparison furnishes explicit expressions for the Ke factor. The Ke factor is tested by means of seven examples.