Abstract
Voids are formed in CFRP laminates by different curing pressure conditions, and they could cause strength reduction. In our previous study, we developed a strain measurement method using fiber location search by image correlation for pictures taken by a scanning electron microscope (SEM). The in-situ three point bending experiment was carried out under SEM, using CFRP specimens with different void volume fraction (V_v) prepared by different curing pressure conditions. The microscopic strain fields in 90° layers under transverse tensile loading were obtained by the above-mentioned strain measurement method, and the relationships between voids and strain fields were discussed in detail. The experimental results showed that strain concentrations occur around voids. Especially voids aligned perpendicular to load caused high strain concentrations, while voids aligned parallel to load caused low strain concentrations.
