Study On Ride Comfort Of Motorcycle Based On Virtual Experiment

As a modern design technology, virtual experiment is the main means to simulation and analysis of the motorcycle's complex work process. The research and application of motorcycle virtual prototype can be a good solution to these key problems exists in development procedures. And it will improve the technique level of motorcycle development with an efficient promoting of motorcycle enterprises'core competence.The engine excitation and road excitation are two main sources of motorcycle vibration. However, in most cases, the road excitation was the only consideration in motorcycle virtual experiments with the neglect of high-frequency vibration caused by engine which may give great effect to ride performance. Based on a certain off-road motorcycle development requires, a ride comfort numerical model was built by using multi-body dynamics analysis software (ADAMS); relevant analysis was carried with comprehensive consideration of both engine excitation and road excitation. As there are no unified standards available at present, the results of motorcycle virtual experiment was evaluated through study of overseas and domestic research result. The whole research contents as follows.(1) Built geometric models of main components in motorcycle by using UG, Established the numerical model of motorcycle ride comfort by importing geometric model to ADAMS through the Parasolid file and setting constrains in ADAMS.(2) Established the dynamic response test by imposing vertical incentive on front and rear wheels of two-channel motorcycle road simulator of MTS. Through the comparison with result generated by virtual experiment, it proves that the numerical model can embody the natural characteristic of physical prototype and it can be an effective model for ride comfort experiment.(3) Got two excitation files of road by compiling respective programs in different work conditions including a low speed at 30km/h and a high speed at 60km/h. The result has preferably coherence with theoretical power spectrum.(4) Carried on the virtual experimental simulation analysis to the motorcycle harshness through three conditions, which including engine incentive, road roughness incentive, the combined action of the both. Through the comparison of PSD, it resulted that the effect when two excitation work together was equivalent to the superposition of effects when both two excitations work separately.(5) The optimum design of engine mounting was carried to improve the ride comfort. Comparison of ride comfort between two stages shows that the all directions'acceleration was decreased by 24.8% to 60.2% at lower speed and the percentage was 84.0% to 90.9% at higher speed. By referring to the relevant research results overseas and domestic, it shows that the ride comfort can meet the criterion after engine mounting optimum.