Nonlinear Dynamics of SMA Oscilator Using an Internal Constraints Model
Larissa Maciel da Fonseca1; Alberto Paiva1; Marcelo Amorim Savi2
1 Universidade Federal Fluminense; 2 Universidade Federal do Rio de Janeiro
doi:10.20906/CPS/COB-2015-2497
Resumo
The amazing properties of Shape Memory Alloys (SMA) have been inspiring many smart structures applications. The mechanical force provided by this stuff comprises hystereses due to either temperature or stress-induced phase transformations, introducing an intrinsic nonlinearity on the mathematical formulation. A consistent constitutive model able to capture the general thermomechanical behavior of SMAs is required in order to adequately describe some specific dynamical features. This contribution deals with the dynamical modeling and numerical simulation of a one-degree of freedom oscillator, including a SMA restoring element, whose constitutive behavior is described through an internal constraints model present in the literature. Numerical simulations are carried out, using the fourth-order Runge-Kutta method. The results attest both the energy loss due to the hysteretic nature of SMAs and the presence of multiple equilibrium points, indicating system's sensibility to initial conditions. Besides, the temperature dependence is investigated, highlighting the adaptive features of SMAs.
Palavras-chave: Shape Memory Alloy; Smart Structures; Numerical Simulation