Embedding shape memory alloys (SMA) wires or ribbons in a matrix material enables both the traditional advantages of composites plus unique capabilities of shape control, frequency control, tunable yield stress, and damage repair. To provide a guideline for design of self-healing shape memory alloys composites, we developed a finite element model to simulate the self- healing of a metal matrix composite reinforced by shape memory alloy wires. In this model, the SMA wires and elastic-plastic matrix material are modeled separately. A special user-defined material obeying three-dimensional constitutive law was developed to simulate the behavior of SMA wires. By using this model, we successfully described the self-healing procedure of this composite which has been also realized experimentally (Figure 1). Furthermore, we extended this numerical approach to appropriately model the bonding between SMA wires and matrix and to evaluate the impact of the interaction on the stress distribution in the wires and overall composite response.
The self-healing property of the SMA-reinforced metal-matrix composite is extensively studied, with a focus on designing a three-dimensional composite structure with optimal self-healing performance. Different reinforcement materials, healing temperatures, and architectures with varying number, lengths, locations, orientations, as well as pre-strains of SMA wires are investigated. Many useful conclusions are drawn from this study, which can be validated in experiments by our collaborators NASA and University of Florida. This work provides valuable guidance in designing and optimization of self-healing structures that can be utilized in aeronautic applications.
Researcher on the project:
D.S. Burton, X. Gao, and L.C. Brinson, Finite element simulation of a self-healing shape memory alloy composite. Mechanics of Materials, 2006. 38(5-6): p. 525.
Gao, Qiao, Brinson, Implementation of Reorientation Kinetics in Uniaxial SMA Modeling for ABAQUS, manuscript in preparation, (2007).
X Gao, D Burton, TL Turner, LC Brinson - Journal of Engineering Materials and Technology, 128, 285 (2006).