ABSTRACT
Research on the strength of fiber-reinforced plastics (FRP) is roughly classified into two approaches: macroscopic and microscopic. The former, called the “parallel spring model,” has long been used. In this method, a simple model composed of a fiber and a matrix is substituted for a FRP structure, and such factors as elastic coefficient, strength, and so on, are calculated out on the model under the presumption that the longitudinal strains of both structures are the same.
