High structural damping based on the internal snap-buckling mechanism of a continuous metal module

Abstract

A structural module that can bear load and dissipate dynamic energy effectively is desirable. In this paper, a continuous laminated metal module of a preloaded beam bimorph and elastic layer is developed to achieve versatility of damping properties based on internal snap-buckling mechanism. According to nonlinear Euler-Bernoulli beam theory, the dynamic model of this structure can be obtained. Multiple scales method is utilized to derive intra- and inter-well vibratory responses analytically. Based on numerical simulations, this continuous module would have a negative stiffness due to internal snap-buckling behavior in the inter-well oscillation, while the macroscopic displacement remains fixed, which brings about orders of magnitude of energy dissipation within a certain bandwidth. Numerical results demonstrate the essential role that the shape of the function of potential energy plays, in conjunction with the excitation, to determine whether this module can achieve high dissipation. Analytical functions that can be utilized to determine the loci of critical bifurcations are derived to approximate the effective bandwidth for high dissipation oscillation. For the structures with shallow and closely separated potential wells, the snap-buckling dynamics can occur easily within a considerable bandwidth, even if the system is excited with small amplitudes.