Mode i interfacial fracture characterization of foam core sandwich materials at elevated temperatures

Foam core sandwich materials are being widely used in structural engineering due to their advantages such as lightweight, high strength, and corrosion resistance. But the interfacial bond strength of foam core sandwich materials is weakened at elevated temperatures. In practice, the influence of high temperature cannot be ignored since the composites with foam are sensitive to the change in the environment. In this study, a series of sandwich double cantilever beams were tested at different temperatures to evaluate the effect of high temperatures on the interfacial fracture of the foam core sandwich materials. The temperature range studied was from 30 to 90, noting the glass transition temperatures are 85.7 for the composites and 72.1 for the foam core, respectively. In the meantime, the mode I interfacial crack propagation and its corresponding interfacial strain energy release rate were analyzed. Furthermore, an analytical model, considering the change in temperature, was proposed to predict the strain energy release rate of mode I interfacial facture of the foam core sandwich materials. The analytical results were found to be well matched with the experimental results.