The Dynamic Analysis For The Riding Performance Of Motorcycle Multibody System On Virtual Prototyping

As key performance index, riding stability, maneuverability and vibration comfortcapacity of motorcycle are investigated on the basis of the qualitative and quantitativeanalysis for algebraic and differential equation on the motion and dyanmics ofmotorcycle numerical model. Motorcycle is multibody system with sophisticatedtopological non-tree configuration made of mechanical, electricaly, hydraulical andcontrolling system, and turns to be high speed machine with lighter weight.Sincemotorcycle subjects to large degree of freedom and rough running condition, it is hardto make elaborate quantitative analysis for its dynamic behavior from the simplifiedmodel with lower degree of freedom. Simutaneously, in traditional design for newmotorcycle, repetitative cycle for design, mock-up and test is time-consuming andcostly; some performance tests are unpractical; non-linear suspension system is hardto adjust; road tests could not produce same results in repetition by moreuncontrollability, all above retard the procedure of motorcycle research anddevelopment. This paper is devoted to establish accurate motorcycle virtual prototypeon the basis of multibody system dynamics under road stochastic excitation and highfrequency engine excitation in order to fulfill the simulation for motorcycle dynamicresponse in systematical way, moreover, flexible multibody system is applied toinvestigate the dynamic behavior on the condition that non-linear elements is addedinto the system, especially with high speed parts flexibility. The main content andconsequence in this paper as follows:1. Apply vitual prototyping to establish motorcycle digital model andbody-vehicle-road multibody system, which work under virtual test environment. Thecomparison for dynamic property is performed between the simplified model ofvehicle lumped mass system and high-fidelity virtual prototype according totopological configuration and dynamical differential algebraic equation so that themethod of quantitative analysis of motorcycle dynamics, the effect of simulationanalysis by virtual prototype is also verified by real test.2. Establish tyre dynamic model in ADAMS while road roughness value in MATLABaccording to power spectrum density of different roads input into ADAMS to formroad model. In non-linear interaction between road and tyre model, simulation for tyrelongitudinal slip, lateral slip and aligning torque is fulfilled to be reliable analysisbasis for the research on motorcycle riding dynamics and vibration excitation. 3. The research on the vibration of motorcycle running at high speed should not focuson the road stochastic excitation, but need to determine the contribution of engineexcitation from unbalanced torque and force. The engine multibody virtual prototypeis established for the research on the dynamical property, for valve train working incomplicated way so that the deformation of major parts should be discussed in rigidand flexible multibody system coupled, the dynamics of which affects motorcycledynamic response to combined excitation.This paper established motorcycle multibody system with complicated topologicalconfiguration according to CAD geometry solid model and computational multibodydynamics, which is virtually tested under the interation between tyre model and roadmodel in order to analyze its dynamic response in time domain and frequency domainunder combined excitation from road and engine, so that vitual prototype ofcomplicated mechanical multibody system becomes an effective way for the researchand development of motorcycle and the simulation for its dynamic behavior.