Research On Ride Comfort And Road Friendliness Of The Heavy Vehicle Based On Virtual Prototype Technology

The ride comfort performance is one of the important subjects in the automobile technology developing and has caused widespread concern. This dissertation analyses ride comfort of heavy truck by experimental data and simulation results.Firstly, the experimental results of ride comfort for heavy truck are analyzed. According to the processing of experimental data, the effects of driving speed on vertical accelerations of vehicle mass centre, cab seat and six axis heads are researched. In the case of full load with the running speed at20km/h,30km/h and60km/h, the time-frequency domain curves of vertical accelerations at eight measuring points are got too. The results show that:when the vehicle speed is less than60km/h, the vertical accelerations at eight measuring points increase with the increase of running speed.Secondly, a heavy truck model is established with ADAMS software according to the experimental car parameters. The model includes front and rear suspension, tires, cab system and so on. The class B random road model is also established. The time-frequency domain curves of vertical accelerations at vehicle mass centre, cab seat and six-axis head are obtained by vehicle dynamics simulation, and compared with the experimental results. After the correctness of the vehicle model is verified, the random dynamic loads is analyzed. It is found that the vehicle dynamic load coefficient and the tire aggregate force are significantly affected by the load of vehicle, the rear suspension spring stiffness, the shock absorber damping at front suspension and the road surface roughness level, and the increase of vehicle load, rear suspension spring stiffness and road roughness will lead to road destroy.At last, two types of road continuous hump are established with3D ROAD pavement modeler in ADAMS software. One type of hump has small width and more cycles and is called a type. The other type of hump has big width and less cycle and is called b type. By the simulation of the vehicle passing through two types of hump, the effects of hump width and height on body vertical acceleration and wheel vertical tire force are analyzed. The result shows that:the height of road continuous hump is proportional to the control-speed and the width of the hump is inverse proportional to the control-speed; when the control speed is less than80km/h, the a type of hump(with450mm and8mm height) can get good speed-control effects; when the control speed is less than70km/h, the b type of hump(with600mm and8mm height) can get good speed-control effects and ensure that the car has a better ride comfort and road friendliness in the same time.