ジュール発熱による電気抵抗変化を利用したCFRP構造物の層間はく離検知

抄録

Delamination of CFRP structure is detected by means of electrical resistance change due to Joule heating in the present study. A CFRP beam is heated up by applying electric current through electrodes mounted on the surface. When the CFRP beam is heated up, the thermal expansion at the part with a delamination is different from that at the undamaged part, and the difference of the thermal expansion affects the electrical resistance change with elevated temperature because CFRP has piezoelectricity. The electrical resistance changes between the electrodes are measured using bridge circuits just like using conventional strain gauge. In addition, the effect of electrode's damage on the electrical resistance change is also considered because the quality of the electrode is important to identify delamination. Electrical resistance change due to Joule heating is measured using a cross-plied CFRP beam with a delamination and electrode's damage, and as a result, delamination detection is even possible with a damaged electrode.