Buckling Metamaterials for Extreme Vibration Damping.

Damping mechanical resonances is a formidable challenge in an increasing number of applications. Many passive damping methods rely on using low stiffness, complex mechanical structures or electrical systems, which render them unfeasible in many of these applications. This article introduces a new method for passive vibration damping by allowing buckling of the primary load path in mechanical metamaterials and lattice structures, which sets an upper limit for vibration transmission: the transmitted acceleration saturates at a maximum value in both tension and compression, no matter what the input acceleration is. This nonlinear mechanism leads to an extreme damping coefficient tan δ ≈ 0.23 in a metal metamaterial-orders of magnitude larger than the linear damping coefficient of traditional lightweight structural materials. This article demonstrates this principle experimentally and numerically in free-standing rubber and metal mechanical metamaterials over a range of accelerations. This article also shows that damping nonlinearities even allow buckling based vibration damping to work in tension, and that bi-directional buckling can further improve its performance. Buckling metamaterials pave the way towards extreme vibration damping without mass or stiffness penalty, and as such could be applicable in a multitude of high-tech applications, including aerospace, vehicles and sensitive instruments. This article is protected by copyright. All rights reserved.