Abstract:
This paper presents a multi-degree-of-freedom model for the design and analysis of
mechanical snubbing in elastomeric isolators. The model consists of a three degree-of-freedom
rigid body that is assembled to a rigid frame by means of elastomeric isolators and a snubbing
system. The isolators are supplemented by the snubbing system so as to limit the displacement
of the rigid body in all three directions of motion when the system undergoes transient loading
or overloading conditions. The model is piecewise non-linear and uses normalized Bouc-Wen
elements in order to capture inherent hysteresis of the elastomeric isolators and the snubbing
system as well as the transition in stiffness and damping properties resulting due to inherent
coupling between the isolators and the snubbing system. Separate elements are used to model
the enhanced stiffness resulting from the snubbing system in the translating directions of
motion. A set of elastomeric isolators and snubbing systems is used for data collection,
characterization and model validation. The data collection is carried out at multiple strain
amplitudes and strain rates. A conventional least squares based parameter identification
technique is used for characterization. The completely characterized model is then used for
simulating the response of the rigid body and the simulation results are compared to
experimental data. The simulation results are found to be in general agreement with the
experimental data.
