Random vibration studies of an SDOF system with shape memory restoring force

Intelligent and adaptive material systems and structures have become very i mportant in engineering applications. The basic characteristic of these sys tems is the ability to adapt to the environmental conditions. A new class o f materials with promising applications in structural and mechanical system s is shape memory alloy (SMA). The mechanical behavior of shape memory allo ys in particular shows a strong dependence on temperature. This property pr ovides opportunities for the utilization of SMAs in actuators or energy dis sipation devices. However, the behavior of systems containing shape memory components under random excitation has not yet been addressed in the litera ture. Such a study is important to verify the feasibility of using SMAs in structural systems. In this work a nondeterministic study of the dynamic be havior of a single-degree-of-freedom (SDOF) mechanical system, having a Nit inol spring as a restoring force element is presented. The SMA spring is ch aracterized using a one-dimensional phenomenological constitutive model bas ed on the classical Devonshire theory. Response statistics for zero mean ra ndom vibration of the SDOF under a wide range of temperature is obtained. F urthermore, nonzero mean analysis of these systems is carried out. (C) 2000 Elsevier Science B.V. All rights reserved.