Abstract
Fiber reinforced plastic (FRP) materials have many advantages over traditional civil engineering ones. However, it is difficult to exactly understand their mechanical characteristics which are affected by various kinds of properties of polymer as a matrix and fibers as inclusions. In the case of designing and developing FRP, it is often modeled as a macroscopically anisotropic elastic material, whose elastic constants are already determined, and no microstructures are directly considered. In this study, we attempted to identify elastic modulus of vinylester resin and fibers, which make up hybrid FRP composite beams used in bending tests by three-phase Mori-Tanaka averaging method in which a virtual matrix is introduced to a two-phase composite. Moreover, by inputting macroscopic elastic constants calculated from the identified values to a versatile finite element analysis software, we simulated bending behavior of the hybrid FRP composite beams and proposed a simple model for delamination of the upper flange from the result of stress analysis.
