Excitation techniques for testing bike vibration transmission in the laboratory
Vibrations generated by road surface defects are a significant source of discomfort for cyclists. This paper presents two very different laboratory techniques for studying road bike vibration. The first technique uses a treadmill with a modified belt surface. The second technique is based on the use of a road simulator that was developed specifically to generate displacement excitation under the wheels of the bike. Broadband excitation generated by coarse pavement surface is also evaluated in this study. The objective of this paper is to evaluate and compare the relative merits of these two approaches. For the purposes of evaluation, we have described a technique to obtain a realistic measurement of input in real road conditions. Our results demonstrate that the road simulator succeeds in producing adequate displacement profiles in the vertical axis resulting in a vibration frequency spectrum that closely resembles the measurements in real road conditions. Limitations in current actuator capacity prevent to reproduce very coarse road conditions. Finally, more work is needed to develop an appropriate belt surface that can generate sufficient energy excitation above the 25 Hz range.
Unable to display preview. Download preview PDF.
- 2.Richard, S, “Étude du comportement dynamique d’un vélo de route en lien avec le confort du cycliste”, MSc. Thesis, Université de Sherbrooke, 2005Google Scholar
- 3.IS0 2631-1 (1997), Mechanical vibration and shock -Evaluation of human exposure to whole-body vibration -Part 1: General requirementsGoogle Scholar
- 4.Richard, S. and Champoux, Y., Evaluation of road bike comfort using classical and operational modal analysis, Proceedings of IMAC XXIII, 2005.Google Scholar
- 5.Brassard, F, “Développement d’un simulateur de vibration pour vélo de route”, under revision, 2010Google Scholar
- 7.Ewins, D.J., “Modal Testing Theory, Practice and applicaton, 2nd edition Reseach Studies Press, 2000Google Scholar