The one-dimensional isothermal pseudoelastic theory of shape memory alloys which the present authors proposed has been further exploited in order to clarify the thermodynamic meaning of the interaction energy introduced in the theory. From the equilibrium condition of the two-phase state, it is shown that the partial derivative of the interaction energy with respect to the phase fraction represents the thermodynamic driving force of the phase transformation. Functions for the interaction energy are derived from the definition of the driving force of the phase transformation in equilibrium. Analytical results predicted by the present theory agree well qualitatively with available experimental observations. Tanaka's transformation kinetics are also well modelled by the present theory.

This paper presents the concept of a new vibration control system in which motions of an Al-Fe alloy thin beam/plate with magnetized segments can be suppressed or activated through electromagnetic forces induced by an applied electric current. Analytical evaluation of the induced electromagnetic forces acting both on the electric current applied and on the magnetized segments are derived from an electromagnetic consideration. To examine the feasibility of the proposed vibration control system, we have formulated a simple regulator problem in which the disturbed motion of the thin alloy beam caused by an impulsive force is suppressed.

This paper presents an extension of the authors' previous analyses on the one-dimensional pseudoelastic theory of shape memory alloys (SMA), in which an interaction energy has been introduced to represent the energy dissipation during the phase transformation. From the equilibrium condition of the two-phase state, we show that the partial derivative of the interaction energy with respect to the phase fraction represents the thermodynamic driving force for the phase transformation. Two functions for the interaction energy are derived from the assumptions about the driving force of the equilibrium transformation. Using these interaction energy, we also examine the stability of equilibrium state and the formation of subloops due to incomplete transformations. Analytical predictions by the proposed theory agree well qualitatively with available experimental observations.

By introducing an interaction energy function, the first two of the present authors proposed a one-dimensional pseudoelastic theory of shape memory alloys, which has been demonstrated to model complicated experimental results and Tanaka's transformation kinetics qualitatively well.To study the stress-strain-temperature relationship, we will further develop the pseudoelastic theory by introducing temperature-dependent terms in the free energy function proposed by Ranieki and Bruhns. In addition, the effect of temperature is included in the interaction energy. For computational analysis, material parameters are estimated from data measured by Tobushi and his coworkers in their experiments. Numerical results show that predictions by the present theory agree with some essential feature of their experimental results.

Introducing an interaction energy in the free energy function, the first two of the present authors proposed a onedimensional pseudoelastic model of shape memory alloys. The model has been demonstrated to represent qualitatively well some complicated experimental data on stress-strain-temperature relationships. To study the effect of large hysteresis due to pseudoelasticity of the alloys on their vibrational behavior, we carry out numerical simulations of vibration of a simple mass-spring system connected with a prestrained shape memory alloy wire whose constitutive equation is expressed by the present authors' pseudoelastic model.