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 of their capability of damage monitoring by measuring change in electrical resistance from the early stage of damage, but the former is inferior to the latter as an application because of the difficulties of mass production and high cost. CFGFRP composites are already commercially used as sensor rods for diagnosing the health of concrete structures in skyscrapers in the architectural field or in security walls for preventing an invader in the security field. A method based on monitoring damage by measuring changes in the electrical resistance of structural materials is promising for improving the reliability of material. (C) 2001 Elsevier Science Ltd. All rights reserved.