Moment Deflection Curves Research Articles

On the Yielding of Mild Steel by Bending

The moment-deflection curve of a mild steel beam remains nearly straight until the applied moment reaches as high as 1.5 times of Ms, where Ms denotes the moment when the stress of outermost fiber becomes the equivalent yielding stress σs in tension test. To investigate the phenomena, the surface stress of uniformly bent bar of 0.09% carbon steel was measured by means of X-ray and the stress distribution within the cross section was found utilizing residual stress measurement by corrosion method. As the results, we concluded that the deformation is perfectly elastic as far as the applied moment does not exceed Ms. And even beyond this limit, the surface stress remains under σs. Some analytical method is then introduced to obtain the stress distribution.