Vibration control of a glass fiber reinforced plastic beam with shape memory alloys

Abstract

Vibration control of structures using smart materials has been an important topic of research in recent years. Among them, piezo electric materials have been used prominently due to the absence of mobile parts and their characteristics of light weight, high force generation with less power consumption. In spite of these advantages, they require high excitation voltages to control displacements in micro inch range. Shape memory alloys represent an attractive alternative as they require relatively lesser voltages to generate displacements in the neighbourhood of an inch. This paper demonstrates the usage of Shape Memory Alloy actuators in controlling the flexural vibrations of a flexible beam. The beam is made of Glass Fibre Reinforced Plastic with attached shape memory alloy wires on its top and bottom surfaces. The transient response of the beam subjected to harmonic excitation (with and without control by SMA wires) is determined theoretically using finite element method. An experimental apparatus involving a computer controlled setup is used to experimentally determine the same characteristics of the beam when subjected to same excitation. The results obtained from both the approaches are compared and are used to demonstrate the potential of shape memory alloys in controlling the vibrations of flexible structures.