In this paper, we examine the potential for coexisting responses in a harmonically forced buckled beam. It is shown experimentally that such structures may present many more responses than might be observed using frequency sweep-up and sweep-down testing, with some responses being observed only very infrequently. The primary contribution of this work is the experimental approximation of the basins of attraction of the competing behaviors using stochastic interrogation, which uses strong, but random, perturbations to map out the initial conditions that tend to each attractor. This procedure is especially difficult in experimental studies of distributed systems; hence, we focus on the process of stochastic interrogation itself and strictly in an experimental context.
Stochastic interrogation of competing responses in a nonlinear distributed system