Experimental and numerical investigation on the interfacial behavior of shape memory alloy (SMA) /Epoxy composites.

Shape memory alloy (SMA) composites have been extensively used in various engineering fields as smart structures. The interface between SMA fiber and matrix has an important role on mechanical properties of composite materials; however few works investigated the effect of interface zone. In the present paper interfacial shear strength between SMA fiber and epoxy matrix was evaluated experimentally using fiber pull-out test. Moreover, the effect of pre-strain of SMA wires on the interfacial behavior was studied by pre-straining the SMA wires to 2% and 4% pre-strains. Experiments were conducted in both Martensite and Austenite phases of SMA. In addition, numerical modeling of pull-out test was performed using ANSYS Parametric Design Language (APDL) and cohesive zone model (CZM) approach. Results showed that pre-straining SMA wire in Martensite phase caused enhancement in interfacial shear strength due to recovery force generation 9.66% and 33% improvement of interfacial shear strength was achieved at 2% and 4% of pre-strain, respectively. However, enhancement of interface behavior wasn’t occurred when SMA fibers subjected to pre-tension in Austenite phase.