Modal damping ratio calculation for finited of mechanical systems with viscous elastic bearings using virtual instrumentation

Résumé

This paper proposes an approach of a finite DOF dynamic model for the rigid-solid with multiple neoprene apparatus bearings modeled as viscous elastic dampers. After a short presentation of the physical model of the solid rigid with multiple bearings, the correspondent linear mathematical model in generalized coordinates is determined. The decoupled differential equations of motion are obtained by using linear modal transformation q=V-1 considering that all the dissipations are linear (structural damping). The article presents the virtual instrument developed on the basis of LabView® ver. 8.5 from National Instruments, which was used for the modal analysis in site of a Romanian highway bridge and for the identification of modal damping ratio of the neoprene bearing system.