The dynamic mechanical response of fiber-reinforced beams to large transverse loads

The paper describes the results of experiments on fiber-reinforced metal beams which have been subjected to dynamic transverse loading. The beams were fabricated by embedding sets of parallel steel wires in a matrix of lead-tin alloy, and were clamped at one end. The transverse dynamic loading was applied to the tip of the beam so that the problem was one of the transverse deformation of a composite cantilever. Two separate techniques were employed to load the specimens, one being to hit the end with a fast moving hammer in a “Hyge” Shock Testing Machine; the other was to detonate an explosive charge in contact with a small projectile close to the tip. The deformations were monitored by a number of different experimental techniques and the final plastic transverse deflection of the tip as well as the final position of the plastic wave front were compared with the theoretical predictions of Spencer, Jones and their co-workers. The agreement was found to be very satisfactory. In making these comparisons strain rate effects in the lead-tin matrix metal had to be allowed for and this was done with the help of a separate set of tests.