Snap-through of a bistable beam using piezoelectric actuation

Abstract

The paper presents the snap-through of a bistable system using piezoelectric (PZ) actuation. The bistable system consists of a pre-buckled beam fixed between two jaws. The bistability and snap-through of the beam are modelled using two approaches. An analytical model is first implemented. The results are compared to a full finite element simulation. These modelling approaches are used to find the optimal positioning of the PZ patches used for switching. The PZ-actuated snap-through is then modelled using both an analytical equivalent moment model and finite element simulations. An experimental validation setup is developed accordingly. The validation addresses all aspects of the modelling: bistability, snap-through and PZ-actuated snap-through. For the latter two configurations were studied, namely a switching actuated by a single PZ patch or by two patches. A remarkable agreement is found between both modelling approaches and experimental measurements. The proposed analytical modelling tool can be used for rapid pre-design of bistable devices. It is for instance shown that a centimetre-scale steel-device with an initial transverse displacement about 1 mm can be switched with a few-Newton force or alternatively with a few hundreds of Volts using a PZ patch.