Hygrothermal ageing of polymeric sandwich structures used in structural engineering

Foam core polymeric sandwich structures have been widely used in structural engineering due to their advantages such as lightweight, high strength, and so on. However, the mechanical properties of face sheets and foam cores, and the interfacial bond strength of sandwich structures are affected by the combined hygrothermal conditions, which is common in the most civil engineering applications. In this study, the mechanical properties of face sheets and foam cores in the combined hygrothermal conditions were investigated. Meanwhile, a series of sandwich double cantilever beams were tested at different ageing time to evaluate the effect of ageing time on interfacial fracture of polymeric sandwich structures. Furthermore, an analytical model, considering the effect of hygrothermal ageing, was proposed to predict the strain energy release rate of mode I interfacial fracture of the polymeric sandwich structures at different ageing time. The analytical results were found to be well matched with the experimental results.