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In recent years, with the rapid development of automobile industry, especially the vigorous promotion of new energy vehicles, CAE simulation analysis technology plays an increasingly important role. Differential is a key component of vehicle drive line system, its main function is to meet the different demands of the wheels on both sides when turning. The differential is composed of differential case, planetary gears, planetary gear shaft and half-shaft gears. Because of complex working conditions and poor stress environment, fatigue damages are easily occurred on these components. If the fatigue life of differential can be predicted by simulation analysis technology, it will provide a basis for vehicle design, which will reduce the cost of practical test. In addition, the structure can be optimized by simulation analysis, so as to improve its performance and fatigue life. However, the structure of differential is complex, and it is difficult to analyze its fatigue life.

The NVH performance is one of the most important concerns in vehicle development. For all-wheel drive (AWD) vehicles and rear-wheel (RWD) drive vehicles, prop shaft is a major transmission component which may cause various NVH problems. This paper focuses on the vehicle NVH problems caused by the second order excitation force of prop shaft. In order to control the NVH performance of the prop shaft efficiently and fundamentally, this work first studied the rotation kinematical characteristics of prop shaft. Then a rigid-elastic coupling model of vehicle driveline was built with the theory of multi-body dynamics. With this model, the sensitive factors that may affect the second order excitation force were investigated. This paper also describes a case study to verify the conclusions which are revealed from the theoretical calculation and the simulation.

In the driveline system of all-wheel drive or rear-wheel drive vehicle, drive axle is a major transmission component. Within the perspective of noise and vibration, drive axle is not only a transfer path of the excitation from engine, but also an excitation source because of the engaging movement of its inner gear sets. As a precision assembly, the design parameters and manufacture processes of drive axle have a great impact on the NVH performance of vehicle. This paper proposes a workflow and a cascaded targets system for NVH development of vehicle drive axle. In order to efficiently and fundamentally control the NVH performance related to drive axle, this work first studied various kinematical and structural characteristics of component parts to conclude the key design parameters.

Compared with the traditional vehicle drivetrain system, the electric drive system is characterized by one or two transmission ratio, higher maximum speed and faster torque response. Therefore, NVH problem of electric drive system is more complex. In the development of electric drive system, NVH problems caused by structural vibration, especially the torsional vibration, are easy to occur and difficult to solve. The purpose of this study is to further study the structural characteristics of the electric drive system and its response characteristics under various vibration excitations. The research object is an electric drive system under development, which adopts two-stage and fixed ratio transmission, the maximum speed is 12000 rpm. In the on-vehicle test, an unbearable noise has been found in this system under certain running condition. According to the NVH measurement result, this noise was caused by the system resonance at a certain frequency.