Chaotic Motion in Multistable Mechanical Metamaterials under Periodic Excitation
Talk, APS March Meeting, Minneapolis, MN
Multistable mechanical metamaterials (MMM) have demonstrated wave guidance capabilities, energy harvesting, and mechanical computing by arranging multistable unit cells into arrays. The transition between stable configurations of MMM has primarily been activated and modeled considering quasi-static forcing. In this work, transverse oscillatory loads are used to manipulate the response of a one-dimensional chain of bistable arches. By varying the magnitude and frequency of excitation, we tailor the motion of the structure with respect to its stable equilibrium states. We reveal regions within the parameter space ranging from intrawell motion constrained to a single energy well to periodic and chaotic interwell motion which vacillates between multiple energy wells. The dynamics of the nonlinear system will be analytically studied by solving the continuum equations of motion with direct time integration methods, numerical continuation techniques (pseudo-arclength continuation), and methods from dynamic analysis (Lyapunov Exponents). This study will open avenues to designing and reprogramming structures to exhibit or prohibit large motion for programmable bands of input magnitude and frequencies.