Bistable buckled beam and force actuation: Experimental validations

This paper presents recent experimental results on the switching of a simply supported buckled beam. Moreover, the present work is focussed on the experimental validation of a switching mechanism of a bistable beam presented in details in Camescasse et al. (2013). An actuating force is applied perpendicularly to the beam axis. Particular attention is paid to the influence of the force position on the beam on the switching scenario. The experimental set-up is described and special care is devoted to the procedure of experimental tests highlighting the main difficulties and how these difficulties have been overcome. Two situations are examined: (i) a beam subject to mid-span actuation and (ii) off-center actuation. The bistable beam responses to the loading are experimentally determined for the buckling force and actuating force as a function of the vertical position of the applied force (displacement control). A series of photos demonstrates the scenarios for both situations and the bifurcation between buckling modes are clearly shown, as well. The influence of the application point of the force on the bifurcation force is experimentally studied which leads to a minimum for the bifurcation actuating force. All the results extracted from experimental tests are compared to those coming from the modeling investigation presented in a previous work (Camescasse et al., 2013) which ascertains the proposed model for a bistable beam.