Dynamic Characterization of Rubber O-Rings: Squeeze and Size Effects

Abstract

This paper concerns the dynamic characterization of rubber O-rings used to introduce damping in high speed gas bearing systems. O-shaped rubber rings composed of high temperature rubber compounds are characterized in terms of stiffness and damping coefficients in the frequency range 100-800 Hz. Simple formulas with frequency independent coefficients were identified to express the viscoelastic properties of the O-rings. The formulas proposed approximate the stiffness and damping coefficients of O-rings of general size.

Calculation of high-frequency dynamic properties of squeezed O-ring for bearing support

“…These tendencies agree with previous reports 4), in which the constants (Table 3) were determined by fitting to the experimental results here. (Belforte et al 2008;Tomioka and Miyanaga 2008;Smalley 1977;Darlow and Zorzi 1981;Smalley, Darlow, and Mehta 1978;Al-bender et al 2017). When the damping coefficient was plotted instead of as in literature (Tomioka and Miyanaga 2008), decreased with .…”

“…Hence, analytical prediction of the dynamic properties of rubber components has not been successfully achieved so far. Instead, the dynamic properties of O-rings have been measured experimentally using the actual O-ring structure (Belforte et al 2008;Smalley 1977;Smalley, Darlow, and Mehta 1978;Tomioka and Miyanaga 2008;Darlow and Zorzi 1981;Al-bender et al 2017). These studies clarified that the material, temperature, vibration frequency, and amplitude have significant effects on the high-frequency viscoelasticity of rubber materials.…”

A novel transient computational fluid dynamics-fluid–structure interaction model for the pad adaptive motion and rotordynamic coefficients of hybrid porous tilting pad bearings

“…The radial damping of rubber O-rings was assumed to be 1 × 10 4 N•s/m according to the O-ring damping experimental data. 34 To prevent fluid self-excitation vibration, the tilting stiffness and damping of the spherical hinge were empirically assumed to be very small in comparison with the radial stiffness and damping. 4 A comparison of the steady displacements of the two pads along the pivot is shown in Figure 7.…”

Data-Driven Model for the Dynamic Characteristics of O-Rings for Gas Bearing Supported Rotors

“…A reduced order model to predict the dynamic characteristics of O-Rings is therefore of great importance to assess and predict the rotordynamic performance of the rotor-bearing system. The dynamic characteristics of O-Rings have been investigated by Smalley et al [7], Tomioka et al [8], Green et al [9] and lately by Al-Bender et al [10]. Most of these investigations have been performed focusing on the effects of excitation frequency, temperature, O-Ring diameter, crosssectional diameter and squeeze on the stiffness and damping properties of various O-Ring materials.…”

“…The influence of O-Ring curvature ratio d/D has been discarded after analyzing its effect by varying d/D. Al-Bender et al [10] have performed measurements of Viton and Kalrez O-Rings and provide expressions for the frequency dependence of stiffness and damping for specific O-Ring geometries in a frequency range of 0.1-0.8kHz. Unfortunately, this range only covers the lower end of typical gas bearing supported rotors, which often rotate at speeds above 2kHz [6,12].…”