Nonuniform Torsion of Plate Girders

As one part of a comprehensive investigation of the torsional behavior of built-up structural members, a group of full-size plate-girder specimens were tested under non uniform torsion conditions. The measured stresses and angular distortions were compared with computed values based on available theories. It was found that the theory of S. Timoshenko agreed closely with experimental results for the rolled beam and for the plate girders with relatively high ratios of web thickness to flange thickness. However, the theory was inadequate when applied to specimens with a low ratio of web thickness to flange thickness, for which the web deformation effect is significant.