| Seat is one of the most important parts which connect the occupant with auto-body in automobiles. It is evident that seat performance is critical to occupant safety and comfort. With the rapid development of technology and auto industry, seating systems also have an evolutional development. It is not only a part that can satisfy the occupants' requirement of seating, but a complicated system, which includes Human Engineering, Vibration, Biostatic and Control System.The study on seat can divide into two branches: the research on seat safety and the research on seat comfort. The research on safety focuses on the static performance, the fatigue strength and the performance during impact of seat. And the research on comfort includes the body's static mass distribution, the seated position and the performance of absorbing vibrations.Similar to other product design, the design of seating systems is basic on the requirement of people. Thus, the study on seating systems always pursuing the balance between people's need and the seat design, and also the balance between the seat structure design and various performances of seat. The former relates to the Human Engineering, the seated position, the seat style and so on. The latter concerns the strength, stiffness and vibration performance of seat structure. With the development of the IT, FEM is widely used in the area and has become one of the most important methods. The research work mentioned in this paper is a practical project, which is cooperated with ChangChun Car Bench & Seat Company Ltd. Using software named MSC.PATRAN, a finite element model of a Pakistan train seat structure was set up. Based on the finite element model of seat structure, static strength analysis and fatigue analysis were done.In chapter 1, the domestic and alien status of seat safety and comfort research is investigated. Simultaneously, methods used in seat research, up-to-date achievements and the future of auto seat system design are discussed, and the computer simulation theory and common used software are introduced. In chapter 2, some basic theories and concepts about FEM were introduced. Based on the finite element analysis of seat structure, some method and practical experiences, such as the FE model building, the model simplifying, and the simulation of connect method, were summarized in the paper. In chapter 3, after digested the software, the auto seat system model was set up using MSC.PATRAN. The paper also introduced the general flow of model setting-up. The model consisted of FEM skeleton seat cushion, seatback and seat frame base on the research of seat static characteristic. According to the specifications of seat's experiments given by the cooperator. We finished the simulation of train seat static strength analysis.In chapter 4, some basic theories and methods of fatigue analysis used in engineering were summarized. Using the FE model built in chapter 3, the seat's fatigue performance was simulated with the software of MSC.FATIGUE.The significances of this paper are: Firstly, based on the study in this paper, the finite element analysis method of static performance of seat structure was summarized and provided other people some useful experience. Secondly, the paper made some research on fatigue strength and fatigue life of seat using MSC.FATIGUE, which started a new period of seat safety research.In the future, the seat must become more light, intelligent, and humanistic. Thus, the FEM and topology optimization will be the most powerful tools. The way to make the seat lighter is to try to make the seat structure more reasonable and use some new materials, which have small density and can be formed easily. To let the seat more intelligent is to make seat adjust the seatback angel and seat's temperature automatically according to every occupants' need. The aim of seat humanistic design is to let the system of "people – seat" more harmonious and reasonable. |
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