Self-sensing materials are here Next-generation composites may monitor their own structural health

摘要

Carbon fiber composites-lightweight and strong-are great structural materials for automobiles,aircraft and other transportation vehicles.They consist of a polymer matrix,such as epoxy,into which reinforcing carbon fibers have been embedded.Because of differences in the mechanical properties of these two materials,the fibers can detach from the matrix under excessive stresses or fatigue.That means damage in carbon fiber composite structures can remain hidden below the surface,undetectable by visual inspection,potentially leading to catastrophic failure.”Carbon fiber composites fail catastrophically,so you won't see damage until the entire structure has failed,”said Chris Bowland,a Wigner Fellow at the Department of Energy's Oak Ridge National Laboratory.”By knowing what's going on within the composite,you can better judge its health and know if there is damage that needs to be repaired.”Recently,Bowland and Amit Naskar,leader of ORNL's Carbon and Composites Group,invented a roll-to-roll process to coat electrically conductive carbon fibers with semiconducting silicon carbide nanoparticles.This nanomaterial-embedded composite is stronger than other fiber-reinforced composites and imbued with a new capability-the ability to monitor its own structural health.