<title>Shape memory alloy actuation for active tuning of composite shafts</title>

Abstract

This paper present an experimental-theoretical study on the active tuning of a supercritical composite shaft with shape memory alloy (SMA) wires. To predict the constrained recovery stress in SMA wires, free SMA wires were tested for their thermo-mechanical characteristics, such as the stress-strain curves at different temperatures, the recovery strain at different temperatures and the change in the phase transformation temperatures at different applied stresses. These thermo-mechanical properties were used to determine the coefficients needed in the description of a typical constitutive model for SMA. The predicted value of recovery stress was experimentally correlated. A finite element analysis of a supercritical composite shaft with SMA wires inserted in embedded sleeves was conducted to predict the rotating natural frequencies at a specified recovery force. A 23% increase in the fundamental frequency of a non-rotating composite shaft with 7.4% volume fraction of SMA wires embedded is shown.