A novel approach based on stress-impedance effect to assess the interfacial properties in fiber-reinforced composites

Abstract An effective assessing method for interfacial shear strength (IFSS) of fiber/epoxy composites based on stress-impedance effect of magnetic fiber (MF) has been proposed in this paper upon experimental verification of engineering composites. The dependence of impedance of MF on interfacial stress and IFSS are investigated in succession. It is found that, with increasing resin embedding length on MF, the maximum interfacial stress increases while the impedance decreases due to the stress induced domain structure evolution. The correlation between impedance and IFSS has been successfully expressed by a prediction equation of IFSS, which is proposed herein for engineering fiber reinforced composite based on a stress coefficient from interfacial stress equivalent law. Indeed, applicability of the proposed approach is verified by the case studies of glass and carbon fiber reinforced composites in that the predicted IFSS show good agreement with the corresponding experimental values from widely used microbond test. Comparing with existing mechanical techniques, the proposed method proves to be more convenient and efficient by shorter operation cycle, higher success rate and lower testing cost, which is instrumental to facilitate the advancement of high-performance fiber-reinforced polymer composites.