Theoretical And Experimental Research Of The Riding Comfort Of Motorcycle Based On Virtual Technology

In this thesis, aiming at vibration of a 150 motorcycle a company produced, the virtual prototype technology was introduced into the design of motorcycle. A multi-body-dynamics model of motorcycle was built with road surface and engine exciting by the three-dimensional model software-CATIA and the multi-body-dynamics simulation software-ADAMS. After finishing the creation of the virtual prototype of motorcycle, the test and analysis of the riding comfort of the virtual prototype were carried on. According to the test and analysis, the optimized plan for the riding comfort was proposed. At last the optimized plan was proved effective by the test of the physical prototype. The main research as follow:Firstly, according to the drawings and some technical parameters offered by manufacturer, the main parts of the motorcycle were built in CATIA, and then the three-dimensional full model of motorcycle was built after assembling those parts. After imported the three-dimensional full model into ADAMS with required format, a multi-body-dynamics model of the motorcycle in ADAMS was built according to the relative restraint and movement relation of every part.Secondly, according to the relative parameters, the stably exciting forces including the first order inertial force, the second order inertial force and the capsizing torques of the engine were exactly calculated. The exciting forces of the virtual prototype in ADAMS were defined. Based on the method of superposition of harmonic wave, the curve of the road surface roughness was achieved. This curve was spectrally analyzed and compared with the standard spectrum, and then used for creating the grade B road surface file for the motorcycle's riding comfort simulating experiment.Thirdly, following the ISO 2631 and the ISO 5349, based on the GB/T4970'Method of random input running test-Automotive ride'and other relative regulars, the evaluating program of the motorcycle's riding comfort was written in MATLAB. By this program, the test and analysis on the riding comfort of the motorcycle's virtual prototype were completed successfully.Lastly, according the subjective and objective evaluation of the motorcycle's riding comfort, the modified plan was introduced. The modified plan including adding a rubber bush between the handlebar and the frame with the design stiffness vectors which optimized and qualified in ADAMS and optimizing the stiffness of the front suspension. The comparing test between the unmodified and modified motorcycle's physical prototypes indicated that the riding comfort of the modified motorcycle became obviously better. This conclusion was consistent with the trend of the virtual prototype analysis, and proved the exactness of the virtual prototype of the motorcycle.