Rigid-elastic Coupling Modeling And Ride Comfort Analysis For A Car

With the support of team-oriented commitment to the actual production of the horizontal projects"Rigid-elastic Coupling Modeling and Ride Comfort Analysis for a Car"This paper regards a car as the object of study, and has done the deep study like rigid-elastic coupling modelling, ride comfort analysis, experimental modal analysis of body and car suspension parameter optimization to improve the ride comfort of the car, Reference for the new car in the design stage to comfort design and matching. The study of project has an important practical significance to increase the autonomy of the development and scientific technological innovation in china.Firstly, by using the ADAMS/Car software this paper has built Rigid-elastic Coupling Modeling including front/rear suspension, horizontal stabilizer bar, steering system, power train, tires and flexible body. And the geometric parameters, physical parameters, mechanical parameters of modeling are the same as the real vehicle data. Horizontal stabilizer model is established by Nastran software and then imported into ADAMS software to generate flexible modal. Moreover, on the basis of the real vehicle body modal test data the flexible body model is built in ADAMS/view.Secondly, via studying the random road generated method, this paper has built the B-class roads for the ride comfort analysis. By using the driver seat vibration rms acceleration values as evaluation indexes, this paper has also done the ride comfort of simulation analysis under different speed conditions. The simulation results show that: people would feel uncomfortable at above 80 km / h, but in contrast people would feel better at other speed. In addition, the simulation results meet the requirements of the national standards GB/T4970-1996, verify the correctness of the virtual prototype model and shows that the ride comfort quality of car is better.Again, this paper has analyzed the frequency of the body which affect vehicle ride comfort, and under different modal frequency of the body conditions this paper has done the ride comfort simulation analysis at 60 km/h ride speed in the B-class random road. The simulation results show that: at the frequency of 27.06 Hz, The maximum driver seat floor vibration RMS acceleration is 0.2626 ms-2; at the frequency of 33.53Hz, the minimum is 0.2186 ms-2 reduced by 16.76%. Through this analysis, elastic body of the vehicle has a significant effect on ride comfort, therefore, when doing analysis of vehicle ride comfort, the vehicle should not be regarded as rigid body, the flexible body impact on ride comfort of the vehicle must be considered to improve the accuracy of the simulation.Finally, by using four design variables of front/rear suspension stiffness and damping as the facts this paper has done the orthogonal experimental design of suspension Parameter using L9(34). In accordance with the ISO2631: 1997E of vehicle ride comfort evaluation methods, in this paper, under the unladen 60 km / h condition the driver seat to the floor of the vibration rms is regarded as the evaluation value. The Matlab software is used in the programming calculating process of the driver seat to the floor of the vibration rms value, then the ADAMS software curve the simulation results which are exported in the form of discrete points and imported into Matlab software to calculate the driver seat to the floor of the vibration rms and give the best car suspension parameters. In order to test the reasonableness of optimized program, this paper has also done the simulation analysis of ride comfort of the vehicle by adopting the original and optimized parameters of vehicle suspension under different speeds condition, and the comparison of the before and after simulation analysis results show the the feasibility and effectiveness of the optimization program.