To investigate how the conventional speeds to affect passenger cars ride comfort under a kind of road surface profiles, in multibody dynamics software (ADAMS/Car), a vehicle model was built based on the characteristic parameters of a passenger car. According to the relevant test regulations of ride comfort, the building methods of road surface profiles were discussed. Furthermore, a dynamics simulation analysis of the car was realized by ADAMS/Car and the acceleration-time histories of the seat surfaces X/Y/Z-axis under three conventional driving-speeds were acquired. A special MATLAB program was compiled to calculate the total weighted Root Mean Square (RMS) value by calling the above histories. According to the GB/T 4970-1996, a road test of a passenger car was carried out in the random road surface which equivalent to B level. The car was driven to get the values of total weighted acceleration RMS under three conventional driving-speeds. By comparing the road test result with simulation, the result indicated that the changing trend of total weighted RMS value is consistent as the driving-speed changes, and the ride comfort will decrease when the driving-speed increase. At the same time, it shows that the consistency of the simulation and road test is better.

The multi-body dynamics analysis is an important method to analyze the movement and dynamics characteristics of a car in modern vehicle design process . The twist beam rear suspension which is for rear wheel steering was widely equipped on front engine rear wheel drive vehicles . The modeling of twist beam rear suspensions is always difficult to describe accurately for its unique structural behaviour . First of all , a non-linear method based on multi-body dynamics was used to establish the dynamics model of the twist beam rear suspension system by using the ADAMS/Car . Secondly, the kinematics analysis of the rear suspension was realized and the main suspension parameters (toe angle, camber angle and wheel base) were calculated by changing wheel travel by means of ADAMS/Car . Finally , the suspension was optimized . The result shows that integrative use of ADAMS/Car and ADAMS/Insight in the kinematics analysis and optimized design of the suspensions is rapidly and effectively to design vehicle suspensions .

The water cavity model of engine’s cylinder head is reconstructed by CAD through slicing method. The reverse design methods which are used for complex interior structure’s surface are explored based on slicing method and using software such as Imageware and UG, through modeling the water cavity. The technologies of reverse design such as the measure method of points cloud, points cloud data treatment, curve fitting, fitting error analysis, surface reconstructive and solid modeling are studied. The reverse methods for complex surface are put forward which are based on blocks and features of model. Through the practice of reversing design for cylinder head water cavity model, it is proven that the complex inner cavity components can be reversed by slicing method. The methods can be referenced for similar reverse design.

For multivariate and fuzziness of machine tool selection in CAPP system, fuzzy comprehensive evaluation has been proposed based on analytic hierarchy process. Fuzzy evaluating model system has been built. Through the synthetic analysis of the factors which influence on machine tool selection, fuzzy relation between the effecting factors is set up. Multivariate quantitative problems were solved well, and the uniqueness of machine tool selection is ensured. This method solved the problem of machine tool selection better and ensured the reliability & availability by running on the prototype system.

According to selection of bearings for the impact of multiple factors and ambiguity, a mixed calculation method of variety of algorithms was presented. Problem was better solved to quantitative of the multiple factors. The unique results of the Selection were ensured. Through MFC, Pro/Toolkit of Pro/E interface was called to generate three-dimensional graphics of bearing automatically in VC++ platform. The three-dimensional graphics of bearing could be used directly in the assembly model of product.