Vibration isolation using extreme geometric nonlinearity

TitleVibration isolation using extreme geometric nonlinearity
Publication TypeJournal Article
Year of Publication2008
AuthorsLN Virgin, ST Santillan, and RH Plaut
JournalJournal of Sound and Vibration
Volume315
Issue3
Start Page721
Pagination721 - 731
Date Published01/2008
Abstract

<p>A highly deformed, slender beam (or strip), attached to a vertically oscillating base, is used in a vibration isolation application to reduce the motion of a supported mass. The isolator is a thin strip that is bent so that the two ends are clamped together, forming a loop. The clamped ends are attached to an excitation source and the supported system is attached at the loop midpoint directly above the base. The strip is modeled as an elastica, and the resulting nonlinear boundary value problem is solved numerically using a shooting method. First the equilibrium shapes of the loop with varying static loads and lengths are studied. The analysis reveals a large degree of stiffness tunability; the stiffness is dependent on the geometric configuration, which itself is determined by the supported mass, loop length, and loop self-weight. Free vibration frequencies and mode shapes are also found. Finally, the case of forced vibration is studied, and the displacement transmissibility over a large range of forcing frequencies is determined for varying parameter values. Experiments using polycarbonate strips are conducted to verify equilibrium and dynamic behavior. © 2008 Elsevier Ltd. All rights reserved.</p>

DOI10.1016/j.jsv.2007.12.025
Short TitleJournal of Sound and Vibration