Finite element simulation of a self-healing shape memory alloy composite

A self-healing, metal matrix composite reinforced by shape memory alloy wires is simulated using finite element analysis. A one-dimensional constitutive model for SMA behavior is implemented as a user-defined truss element in ABAQUS. The matrix is brittle and a mode I crack is allowed to propagate through the specimen upon loading. During the loading process the wires undergo a martensitic phase transformation, bridging the crack. To heal the composite, simple heating is required which reverse transforms the wires and brings the crack faces back into contact. When using pre-strained SMA wires for reinforcement, the reverse transformation of the wires during heating causes a closure force across the crack. The method to simulate cracking and “healing” behaviors of the composite allow assessment of the effects of component properties and composite geometry. The results shed light on design of self-healing composites using shape memory alloys.