透過光法による強化プラスチックスの動的特性の測定

抄録

The nondestructive test of Fiberglass Reinforced Plastics (FRP) under stress has called much attention of scientists for investigation of its disintegration by fatigue because the phenomenon of stress-whiting takes place in the test. This phenomenon will thus present significant source for researches. The light wave transmission method will prove more effective than the ultrasonic wave transmission method because the stress-whiting occurs by random reflection. In our experiment, therefore, the light of electric bulbs with tungsten filaments was passed through FRP under stress, and the decrease of the transmitted light was measured. As the relation between the number of cycles and the amount of the transmitted light was obtained in this way, it provides clue to suggest the mechanism of fatigue of FRP. Moreover¹⁾ it revealed also the number of the layers and the direction of the glass fiber. The light wave transmission method is thus shown as both practical and effective as well as easily available for nondestructive test of FRP.