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A lightweight design method of vehicle dash insulators is proposed and investigated in this paper. The lightweight dash insulator, which is composed of double layers of cotton felt with different density and a layer of polyethylene (PE) film and has 55% decrease in weight, is developed and applied in a passenger car, instead of the traditional “heavy layer-soft layer” dash insulator. To evaluate the NVH performance of the lightweight dash insulator, the noise reduction (NR) level index is calculated by using SEA simulation and the sound pressure level and sound qualities in the vehicle are tested under the driving conditions for wide open throttle acceleration in third gear and 60km/h cruising in fourth gear. The simulation and test results show that the vehicle with the lightweight dash insulator has better NVH performance.

With drastically reduction of engine noise, the gear rattle noise generated by the impact between neutral gears inside transmission can be much easily perceived. It is well known that the torsional mode has a direct relationship with the transmission gear rattle noise. This paper establishes a torsional model of a front wheel drive automotive drivetrain, including clutch system, transmission box and equivalent load of a full vehicle, in AMESim software. The experimental engine speed fluctuations at different gears are used to excite the torsional model. The influences of several parameters, including flywheel inertia, clutch stiffness, clutch hysteresis and drive shaft stiffness, on the 2nd order (major engine firing order for a 4-cylinder-4-stroke engine) torsional resonant frequency and the 2nd order torsional resonant peak of the transmission input shaft are analyzed by changing them alternatively.

This workbook, a companion to the book Road Vehicle Dynamics, will enable students and professionals from a variety of disciplines to engage in problem-solving exercises based on the material covered in each chapter of that book. Emphasizing application more than theory, the workbook presents systematic rules of analysis that students can follow in a step-by-step manner to understand the efficiencies or shortcomings of various techniques. Readers will gain a greater understanding of the factors influencing ride, handling, braking, acceleration, and vehicle safety.

This set combines the book Road Vehicle Dynamics with its corresponding workbook companion, Road Vehicle Dynamics: Problems and Solutions. Road Vehicle Dynamics provides a detailed overview of the dynamics of road vehicle systems, giving readers an understanding of how physical laws, human factor considerations, and design choices affect ride, handling, braking, acceleration, and vehicle safety. Chapters cover analysis of dynamic systems, tire dynamics, ride dynamics, vehicle rollover analysis, handling dynamics, braking, acceleration, total vehicle dynamics, and accident reconstruction. The workbook will enable students and professionals from a variety of disciplines to engage in problem-solving exercises based on the material covered in each chapter of that book. It presents systematic rules of analysis that students can follow in a step-by-step manner to understand the efficiencies or shortcomings of various techniques.

Currently, four wheel drive (4WD) system is widely used in Sports Utility Vehicle (SUV) due to the increasing demand of fuel efficiency and dynamic performance by customers. However, propeller shaft consisting of different universal joints and tubes on 4WD vehicle easily induces low frequency bending vibration. This paper analyzes the characteristics of driveline bending vibration of a 4WD vehicle and provides control methods to reduce the low frequency vibration caused by propeller shaft bending resonances. Firstly, the driveline bending vibration model of the 4WD vehicle is established using FEA method and the natural frequencies are calculated. Secondly, the influence parameters, such as universal joint, relative length of two-piece propeller shaft, and tube diameters, on bending frequencies are analyzed by both FEA analysis and physical testing.