Ride Comfort Analysis And Optimization For Light Truck

With the development of society and the continuous improvement of people's life, automobiles are becoming a tool of transportation. A good auto product should be an artwork. At the same time, people have a higher demand for transportation comfort. To ensure the safety, high efficiency and comfort of traffic and transportation, automobile ride comfort is getting more and more important. Automobile ride comfort is one of the most important performances of automobiles. Many automobiles companies are researching the automobile ride comfort and improving it to enhance the competitive power of their own automobiles. Consequently, it will be important work how to analyze, match and optimize the stiffness, damp etc.Combining with the recent development of light truck in an automotive company, the thesis studied the ride comfort analysis and optimization, using the ADAMS software, setting up all the sub-system of the truck, and completing the analysis the whole truck model.First of all, in this study, the performance of the Benchmark truck was tested according to GB /T4970-1996 method of random input running test of automotive ride comfort, the performance goal that the truck will be reached after the subjective evaluation was promoted. Secondly, the whole truck model for analysis was set up–the study focuses on F/R suspension system, steering system, transmission shaft system, power system, tire ,body etc., confirms its parameter and structure form, defines relationship of those parts. Within the simulating process, the writer took more consideration the F/R suspension system, steering system, transmission shaft system. The writer also analyzed thoroughly the geometric deform and stiffness of the F/R spring under the force action, and put forward a new method about setting up the F/R suspension simulating model. In addition, this thesis also analyzed the road model, and set up the road model according to the national regulations. Combined the ADAMS software and road generation software, finally, the B level road file matching the tire model was generated.Using the ADAMS software the writer carried out the simulation calculation, the curve of third octave spectra acceleration average square roots of all points with deferent velocities on the B level road. According to this result, weighted acceleration average square roots and the exposed time under driver's tire-efficiency debasement limit can be calculated. Exampled as the result on 60km/h, the thesis described the ride comfort of light truck. Because of the big suspension's stiffness, this performance was too bad. The vertical weighted vibration's level within the range of 117dB~121dB, is a fairly uncomfortable area to human body; furthermore, it comes unsteadily trend on the higher velocity.According to the result of simulation analysis, the structure and parameters of the F/R suspensions was optimized for the better ride comfort performance; the new design used the less sheet spring; the curves of force-deform and stiffness-deform were defined again. The result from the simulation of ADAMS software indicated that the ride comfort of new design truck was obviously better than original scheme; in case of the vertical weighted vibration's level within the range of 108dB~112dB, although there might be uncomfortable feelings, it was an acceptable result to trucks; further more, the weighted acceleration average square roots were close to the benchmark truck.