Thermal buckling and acoustic vibration characteristics of the shape memory alloy hybrid composite plate

Abstract

Shape memory alloy (SMA) is a smart material which recovers its original shape after deformation with the addition of heating. When the pre-strained SMA is heated with being constrained, a large recovery stress is developed in the material. Shape memory alloy hybrid composite (SMAHC) plates using these characteristics are often referred to smart materials. In this research, thermal buckling and acoustic vibration characteristics of SMAHC plate were investigated. To predict behaviors of shape memory alloys, an efficient engineering model is introduced. For the iso-thermal case, piecewise linear relations between stress and strain at a given temperature are assumed. Martensite volume fraction and stress at the end of the increment are computed using the defined linear transformation paths. For the nonisothermal case, transformation rules of the prescribed iso-thermal model are consistently applied to predict thermal responses of SMA. The presented engineering model was implemented as an Abaqus user material subroutine (UMAT) and the thermal buckling behaviors of the SMAHC panel were investigated. SMA wires enhanced the resistance of the SMAHC panel to the thermal buckling. Hysteric thermal buckling displacement was observed during the heating and cooling processes due to hysteresis in the recovery stress of embedded SMA wires. Vibration responses of SMAHC panel subjected to the thermal and acoustic random pressure loads were also presented. The acoustic vibration responses of the SMAHC panel and the conventional composite (CC) panel were compared. The amplitude of the SMAHC panel was smaller than that of the CC panel subjected to the acoustic load with the sound pressure level (SPL) which is much higher than the SPL causing a snap-through motion of the thermally buckled CC panel.