4. An Experimental-Numerical Hybrid Approach to Analysis of Fiber-Matrix Interfacial Stresses

In this study, the single fiber composite was used to evaluate the stress transfer between a single fiber and a matrix. Single steel fiber was inserted to the epoxy resin, and it was applied the tensile load. Applied load was from 0 N to 177 N, and then the photoelastic images were taken by a digital CCD camera. On the photoelastic analysis, the stress separation was carried out using an experimental-numerical hybrid method. The boundary conditions for a local finite element model, that is, the tractions along boundaries are inversely determined from photoelastic fringes. After determining the boundary conditions for the local finite element model, the stresses can be obtained by finite element direct analysis. Using this input data and the finite element model of analysis region, not only the stress but also the strain distributions were obtained. Consequently, by using the photoelasticity data and geometric data for input data of finite element analysis, accurate data was obtained by the hybrid method for stress separation.