Journal of Theoretical
and Applied Mechanics

36, 4, pp. 879-893, Warsaw 1998

Dynamics of thermally activated shape memory alloy reinforced laminated beams

Marek Pietrzakowski
A way of use of shape memory alloy (SMA) fibers for dynamic response modification of laminated beams is presented in the paper. The considered concept of adaptive control is based on the ability to change the Young modulus during a temperature activated, reversible, martensitic transition that is specific to SMAs. It is assumed that the laminate is midplane symmetric and the corresponding layers of the same fiber orientation are activated simultaneously, and the SMA fibers can freely elongate in the matrix. A cantilever laminated beam with mass distributed on its free edge is subject to numerical analysis. Due to the quasi-steady one-dimensional model of heat conduction, martensite fraction and natural frequency time relations for the phase transition of SMA have been obtained. The influence of temperature on natural frequencies of the system has been analysed for some different locations of activated plies and directions of SMA fibers. The frequency response functions varying with the material phase transformation for a harmonic load acting on the free end of the beam have also been presented.
Keywords: laminate; thermal activation; natural frequencies