Interfacial debond of shape memory alloy composites

A theoretical model for the prediction of interfacial behaviour is successfully developed for composites with pre-strained shape memory alloy (SMA) fiber. A two-cylinder model with a thin SMA fibre surrounding by epoxy matrix is employed for a pull-out test. The material constants and thermomechanical properties of the constituents were determined from a series of tensile tests, stress-recovery tests and strain-constrained tests. All this information is then substituted into the newly developed model so as to predict the debonding behaviour, initial debond stress and critical bonded fibre length. The maximum debond stresses at different activation temperatures are predicted and compared with the experimental results obtained from the fiber pull-out test. The good agreement between experimental findings and theoretical results warrants the application of this new developed theoretical model on the design of SMA-reinforced composites and structures.