Shakedown of Bars under Extreme Loads

This paper is to report on an investigation of shakedown response where the initial load was equal to the fully plastic load. Thus, no preceding yield history was present. A previous theoretical investigation indicated that shakedown deflections where the first load was slightly higher than the fully plastic load were approximately equal to the shakedown deflections where yielding occurred gradually due to a long history of prior cyclic loading. The theoretical deflections of the two types of loading history agreed exactly at the first load level above the fully plastic load. This next load level was in excess of the fully plastic load by 7%. Physical testing to corroborate the theoretical evidence is reported in this paper. A total of three beams were tested.