Hybrid composites with self-diagnosing function for preventing fatal fracture

Design of intelligent material with self-diagnosing function for preventing fatal fracture of the structural material is achieved by hybrid composites consisting of fiber tows or powders in carbon material with a small value of ultimate elongation and glass fiber tows with a large value of ultimate elongation. CPGFRP/GFRP (carbon powder dispersed in glass-fiber-reinforced plastics/glass-fiber-reinforced plastics) composites are superior to CFGFRP (carbon-fiber and glass-fiber-reinforced plastics) composites in respect o f their capability of damage monitoring by measuring change in electrical r esistance from the early stage of damage, but the former is inferior to the latter as an application because of the difficulties of mass production an d high cost. CFGFRP composites are already commercially used as sensor rods for diagnosing the health of concrete structures in skyscrapers in the arc hitectural field or in security walls for preventing an invader in the secu rity field. A method based on monitoring damage by measuring changes in the electrical resistance of structural materials is promising for improving t he reliability of material. (C) 2001 Elsevier Science Ltd. All rights reser ved.