Nonlinear isolator dynamics at finite deformations: An effective hyperelastic, fractional derivative, generalized friction model
2003 (English)In: Nonlinear dynamics, ISSN 0924-090X, E-ISSN 1573-269X, Vol. 33, no 3, 323-336 p.Article in journal (Refereed) Published
In presenting a nonlinear dynamic model of a rubber vibration isolator, the quasistatic and dynamic motion influences on the force response are investigated within the time and frequency domain. It is found that the dynamic stiffness at the frequency of a harmonic displacement excitation, superimposed upon the long term isolator response, is strongly dependent on static precompression, dynamic amplitude and frequency. The problems of simultaneously modelling the elastic, viscoelastic and friction forces are removed by additively splitting them, modelling the elastic force response by a nonlinear, shape factor based approach, displaying results that agree with those of a neo-Hookean hyperelastic isolator at a long term precompression. The viscoelastic force is modeled by a fractional derivative element, while the friction force governs from a generalized friction element displaying a smoothed Coulomb force. A harmonic displacement excitation is shown to result in a force response containing the excitation frequency and its every other higher-order harmonic, while using a linearized elastic force response model, whereas all higher-order harmonics are present for the fully nonlinear case. It is furthermore found that the dynamic stiffness magnitude increases with static precompression and frequency, while decreasing with dynamic excitation amplitude-eventually increasing at the highest amplitudes due to nonlinear elastic effects-with its loss angle displaying a maximum at an intermediate amplitude. Finally, the dynamic stiffness at a static precompression, using a linearized elastic force response model, is shown to agree with the fully nonlinear model except at the highest dynamic amplitudes.
Place, publisher, year, edition, pages
2003. Vol. 33, no 3, 323-336 p.
hyperelastic material, fractional derivative, friction, vibration isolator, viscoelastic materials, vibration isolators, dependent stiffness, rubber cylinders, behavior, systems, formulation, performance, components, calculus
IdentifiersURN: urn:nbn:se:kth:diva-22874DOI: 10.1023/A:1026037703124ISI: 000185798000006OAI: oai:DiVA.org:kth-22874DiVA: diva2:341572
QC 20100525 NR 201408042010-08-102010-08-102012-02-11Bibliographically approved