Using shape memory alloy as dampers : design methodology

Abstract

Many shape memory alloy (SMA) material models have been proposed in the literature, but most are suited only to forward analysis and not to design. This project proposes a generalized friction element, the lambda box, to model the stress-strain curve of SMA during pseudoelasticity. Simulation is carried out to study the dynamic response of such a system under harmonic loading. Three kinds of systems were examined, in order of increasing complexity: the friction damper system, the hysteretic damper system, and the hysteretic lambda damper system, which dynamically is equivalent to the SMA damper system. Using the simulation results, various asymptotes on the design space are identified, and design methodologies for the three systems are proposed. As the determination of the system parameters is decoupled from the actual damper design, a design methodology to dimension and configure the SMA damper is then proposed, for two kinds of problems, initial design and retrofit design.