Modeling of the snap-through of a hybrid bistable laminate by a magnetic force field

The traditional [0/90]T laminate has two stable equilibrium shapes, and it is possible to go from one shape to the other by means of an external force. In the past, researchers have attempted to obtain the snap-through between the two equilibrium states using smart actuators like shape memory alloy (SMA) wires and macro-fiber composite (MFC) patches. The integration of these actuators adds several complications. Moreover these smart actuators are generally attached to the surface of the laminate hence influencing the structural performance substantially. Recently, non contact magnetic actuation was experimentally demonstrated to be a viable method of reversible snap-through. A non-contact actuation using magnetic fields provides an elegant means of achieving reversible snapping without affecting the bistability characteristics of the laminate. In this work, a numerical model has been developed to aid the design of non-contact systems comprising of a ferromagnetic material actuated by a solenoid. The developed model uses a Rayleigh-Ritz based potential minimization to capture the magnetic snap-through of a hybrid [Fe/0/90/Fe]T laminate. The model accurately captures the bistability of the multi-sectioned hybrid layup and can be used for the design of coils to provide the necessary actuation currents.