1) The first element is to conduct research into the geometry of a typical motorcycle suspension and specify a typical wheel diameter and sprung mass. These parameters will be used for your following tasks.
2) The second element of the task is to design a rising rate linkage mechanism that will permit at least 120 mm of rear wheel travel. The above figure can be used as a basis for your design. Your design should clearly show the joints you have chosen, and you should justify your choices. The linkage should be demonstrated in ADAMS model with wheel travel and raising spring rate. It is suggested that you investigate current motorcycle suspension linkages.
3) The third element of the task is to specify the springs and dampers. Your rates should be chosen to provide appropriate ride behaviour under an absolute bump limit (a vertical load equivalent to 3 m/s2). You may analyse it by varying your specified values. You may optimise your design to ensure that the suspension does not reach the end of its travel when it passes the "absolute bump limit".
4) The fourth element of your task is to analyse the behaviour of the motorcycle under motorway conditions with a road profile of a +/- 3 mminput at a wavelength of 30 m. The frequency of the road profile depends on the vehicle speed. You may vary the driving speed and compare your result with the theory you've learned. You should try to ensure that the rear suspension you have designed will provide the maximum comfort for the rider (the student will need to define this criteria), and the minimum force transmissibility on the motorcycle.
Criteria
It is important to you support and justify your design with appropriate research and novel solutions, as long as those solutions are valid and justified.
Over complex models that add little to the accuracy of the solution will not attract higher marks, nor will over simplified models that sacrifice accuracy.
Outcomes addressed
This brief allows you to demonstrate the outcomes (1), (2), (4) and (5) thus:
1) Have a systematic understanding of how to model and analyse vibrating systems.
2) Be able to deploy accurately established techniques in order to analyse and synthesise planar and spatial mechanisms.
4) Apply vibration reduction methods to solve problems involving mechanical vibrating systems.
5) Use computer software packages to critically evaluate mechanisms and vibrating systems.