Abstract
A method to measure the residual stress around the fiber of the smart materials of fiber reinforced composites presented in this study. The residual strains (stresses) around the fibers are released by pushing the fiber out. The released residual strains are measured using an electron moire technique, which can fabricate grids with frequencies up to 10,000 lines/mm on the composites surface so that a displacement sensitivity of lOOnm can be achieved. This method can be applied to almost smart materials using the optical fibers and the fiber-reinforced composites, such as fiber-reinforced plastics (FRPs). Measurements of the interfacial residual stress in SiC/Ti-15-3 and boron/epoxy composites show the validity of the method.
