Particle Impact Damping in Two Dimensions

Abstract

Particle impact damping (PID) is a technique of achieving high structural damping with small metallic particles embedded within a cavity that is attached to vibrating structure. This is a highly non-linear damping mechanism in which energy dissipation is primarily related to friction and impact phenomena. In this work a simple yet detailed analytical model is presented to study PID in two dimensions under transient vibrations. Normal as well as oblique impacts are considered. The effect of cavity size and acceleration amplitude on PID is studied and the results are supported by experiments. Fairly good agreement is found between the theory and the experiment.

Biomechanism of impact resistance in the woodpecker’s head and its application

“…Mechanical excitations above 10 kHz also seriously deteriorate the linear operation of any spring-mass-type MED such as a sensor or actuator. Therefore, an effective method for isolating MEDs from transient high-frequency mechanical excitations is in strong demand and appears to be one of the most remarkable achievements in the design of MEDs [41][42][43][44]. Biomimetically inspired from the spongy bone within a woodpecker's skull, Yoon et al [12] presented woodpecker-inspired shock isolation with which to protect MEDs in high-g military applications accompanied by mechanical shock excitations to tens of thousands of g and to several hundred kilohertz.…”