INSTABILITIES IN A NONLINEAR MODEL OF A PASSIVE DAMPER

During a study of the dynamic characteristics of a wire rope vibration isolation system constructed with helical isolators, an interesting i nstability was observed. Following an experimental investigation of th is system, a semi-empirical model having non-linear stiffness, nth pow er velocity damping, and variable Coulomb-type friction damping was de veloped. Results obtained using ACSL compare well with experimental da ta. The primary emphasis of this paper, however, centers on the instab ilities and large-response behavior of this semi-empirical model. Stab ilizing effects are discussed.