Calculation of Re-spring Bending Moment for Beams of Circular Section

This paper analyzes the changing process of the stress and the strain of pure plastic bending re-spring for beams of circular section.According to the function on stress and strain of re-spring,the condition of the balance of force and the coordination of deform,calculating for mulas ?of re-spring curve and re-spring bending moment are inferred.The result shows that there is more tolerance of theory between the formulaand the method of taking elastic-plastic bending moment as re-spring bending moment according to the classically pure bending theory.