Abstract：Due to the residual stress, asymmetric cross-ply bi-stable laminates can show two different stable deformation states at room temperature. In this paper, the stable configurations and the snap through behaviors of the bi-stable laminate actuated by MFC with center point fixed is studied. Considering the effect of mechanical-electric coupling, the mechanical model of the system is constructed. Based on the classical laminate theory of Krichhoff hypothesis, the potential energy of the system is obtained according to the Von-Karman strain-displacement relationship, and the Rayleigh-Ritz technique is used to obtain the configuration of the bi-stable laminate with MFC actuator. Using numerical method, systematic parametric analyses are conducted to investigate the influences of aspect ratio, ply thickness and laminate size on the bifurcation phenomenon of the bi-stable laminate with MFC. The critical size of bi-stable laminate and the snap-through voltage are predicted. It is found that the out-of-plane displacement of the corner point of the bi-stable laminate with MFC bifurcates with the increase of the side length of the laminate, and the bi-stable critical length increases with the increase of the aspect ratio. The critical thickness of the bi-stable laminate with MFC decreases with the increase of the aspect ratio. Using a specific MFC to actuate asymmetric laminates, there is a certain range of requirements for the size of the laminate. If the size of the laminate is too small, it will lose the bi-stable state, and if the size of the laminate is too large, it will exceed the actuating capability of the MFC. Compared with unidirectional actuating asymmetric laminates, adding MFC on the other side can achieve bidirectional actuating, but the snap-through voltage needs to increase. The snap through behavior of bi-stable laminates is a nonlinear behavior with large deformation, and the study of realization and control of snap behavior are very important for its application in engineering. Bi-stable laminate actuated by MFC is an intelligent deformable structure with fast response, easy control and strong reliability. The results of this paper provide a certain theoretical reference for the structural design of bi-stable laminates actuated by new piezoelectric materials.
2021, Vol. 42 
