A Study on the Plastic Deformations of Some Beams under Impulsive Loading (1st Report)

The writers have already studied the plastic deformations of canti-lever beams considering the strain-rates of materials under large impulse, but the analysis proposed was considerably complicated. So we studied more simplified method of analyzing the large plastic deformations of beams in the case of neglecting the mass of beams comparing with the one of impulsive bodies. Such method here described is considered to be available for the analysis of traffic accidents, for instance, the plastic deformations of guard fence, etc. At any rate, the problems on the fractures and plastic deformations of various materials under impulsive loading are very important and interesting. Among the natural phenomena earthquake and typhoon, etc. are assumed to be one kind of impulsive phenomena. Thus we studied the large plastic deformations of some beams as the first step studying the impulsive phenomena of materials. In this paper was treated the plastic deformations of beams when the impulse acted on the center of the beams or on the tip of the canti-lever beams.