透過光を利用した複合材料の非破壊検査

抄録

Alimina-fiber-reinforced epoxy(alumina/epoxy)is eften used to fabricate to the thermal insulating structire of a superconducting magnet because it has low thermal conductivity and high bending stiffness and strength. The stiffsess of the alumina/epoxy structure is one of the governing factors when evaluating the soundness of a supercenducting magnet. So, to evaluate the soundness of this system, the relation between the degradation in stiffness and the growth in the size of defects in alumina/epoxy must be determined. For this purpose, a new defect-monitoring method using transmitted light through alumina/epoxy was developed. Any defect inside a semi-transparent alumina/epoxy laminate will scatter the light and decrease its intensity. The spectra of the transmitted light were measured using a spectrometer and a halogen lamp. The amplitude of the transmitted light decreased as the stiffness decreased, and the amplitude decreasing ratio was approximately constant from 400nm to 800 nm.