抄録
In recent years the applicable field of glass fiber reinforced plastics (FRP or GRP) has remarkably expanded. This paper is presented to give direction in the proper selection of reinforcement and FRP combinations in order to satisfy the functional requirements and assemblies for repeated impact flexural load using falling weight.
The fatigue strength was investigated macroscopically by measuring the logarithmic decrement and strain under repeated impact load. The rapidly decrease in elastic modulus in fatigue has been observed. Microscopically, the cracks, which appear to be caused by stress wave produced by impact load, were found to occur in the laminated resin layers over considerably wide range along the longitudinal direction of beam and progress across the layer into the fiber bundle of reinforcement. The strength under repeated impact loading was representable in terms of the number of cycles to failure under constant impact energy.
