Behaviour of Grey Cast Iron Under Combined Bending and Tension

Abstract

This paper deals with the strength of grey cast iron components subjected to combined bending and tension, this case of loading being met in C-frames and clamps, crane hooks and various eccentrically—loaded protruding machine parts. Specimens of rectangular as well as trapezoidal sections, made of flake graphite cast iron, were tested under conditions of eccentric loading. With due consideration of non-linearities and inequalities in stress-strain relations in tension and compression, stress distribution for these sections was obtained from strain measurements. The ratio of bending to tensile stress components is herein shown to play a significant role in locating the neutral plane and in identifying the dominating failure stress. The value 2, for this ratio, is shown to draw some demarkation border between the two modes of fracture encountered in the tests. The apparent superiority of bending strength over tensile strength is herein attributed to the widely differing stress-strain relations in tension and compression.