Study On Structural Safety Of Automobile Seat And The Vibration Absorption Performance Of Air Suspension Seat

With rapid development of automotive industry in our country, more and more demand on automotive ride comfort and safety is put forward. Whereas automobile seat is an important component that influences the automobile safety and comfort and it is the most improvable component in automotive vibration absorption.But in our country, the importance of passive safety and dynamic comfort of automobile seat haven't been paid enough attention to by related enterprise, and the means of seat design and research are rather behind the times. Currently, on the safety aspect of automobile seat, many enterprises either blindly design the seat thick and heavy to satisfy the strength requirements so that the function is overmuch, the mass is large, the cost is high and the stuff is waste, or blindly change the seat structure neglecting the potential safety hazard, such as transplanting some high grade seat parts. Furthermore, owing to no standard of structural safety of automobile seat during impact is established in our country presently, tracking out a systematic study means is urgent which is about structural safety of automobile seat and structural development theory and test. Air suspension seat has been used in truck and stagecoach driver's seat using advanced technology in the last few years in the world, the systematical study on it in our country hasn't been carried on at the present time,and the standard of China and enterprise has been established before the invent of the air suspension seat. Hence tracking out a systematic theory and test is urgent which is about vibration absorption performance of air suspension seat, nonlinear elastic characteristics of airspring used in automobile seat and the performance parameter match with vibration absorber. Just under this background,separately using theory of finite element and system dynamics,the structural safety and structural improvement and vibration absorption performance of air suspension seat and the nonlinear elastic characteristics of airspring used in seat and the performance parameter matching with vibration absorber are deeply studied and test in this paper, which are combining with projects that the automobile seat finite element simulation of some changing generation vehicle made in China and the research development of air suspension seat used in 05-Type changing generation truck.The paper is divided into seven chapters: In chapter one,the influence of automobile seat on passive safety and dynamic comfort is detailedly discussed,the research technique and present status of automobile seat passive safety and dynamic comfort in both abroad and home are analysed, the broad contents, aim, meanings and use value of this research work are represented, the classification of seat research is put forward, thus,from now on,the heading of seat study is clear. In chapter two, with studying on driver's seat of some car made in China, the establishing step and the simplifying principle of finite element model are detailedly discussed, the very established static characteristics finite element model of automobile seat is calculated, according to the regulation, the very seat static characteristics confirmation test is conducted using non-electric physical quantity electrical measurement method, the model is reasonable. Seat structural improvement method and proposal are presented, a new way of thinking in seat structural development is groped for, the frame of the very seatback is improved in structure and it is verified by simulation analysis.These work will become the good base of further studies on seat structure dynamic characteristics. In chapter three, on the precondition of no standard and regulation about the structural safety of seat during impact is established in our country, according to ECE regulation, it takes the lead in conducting seat structure dynamic characteristics test study using trolley impact and non-electric physical quantity electrical measurement method, a practical and available test study method is supplied, which has important engineering practice value. By using explicit non-linear theory of finite element and pam-crash software,the seat structural finite element model during impact is established,the dynamic characteristics simulation is analysed, the precision of the model is verified via comparing with the test curve. Via comparing with static characteristics simulation result, a research method of seat structural improvement is presented which requires combining static characteristics and dynamic characteristics analysis and test. The research findings have already been applied to production, acquired good effect. In chapter four, the characteristics of airspring used in automobile seatare studied, as well as the material nonlinearity, cord ply simulation, gas element simulation and non-linear contact. By using HyperMesh and ABAQUS software,the static and dynamic non-linear finite element model of membrane airspring used in automobile seat with air suspension are established,the simulation is analysed,the precision of the model is verified via comparing with the test curve. On the precondition of no standard and regulation on airspring used in automobile seat is established in our country, a practical available model and research method for designing and simulating airspring used in automobile seat is presented, which has significant theory meanings. In chapter five, the vibration absorption performance of air suspension seat of the 05-Type changing generation truck is studied and the vibration absorption performance test is conducted for the first time in our country, including seat cushion stiffness and shock absorber. And test set for the elastic characteristics of airspring used in seat is self-designed. The static stiffness and dynamic stiffness of the four different stiffness airsprings and transferring property of seat (including different mass test, testee test and floor table test) are studied. The mechanism slave driving control machine is researched and developed, which is sensitive to control, low cost, keeping the height immovable when different weight driver ride on it and the air suspension seat is good in vibration absorption performance. The influence of control machine that includes the adjust cam and the position of cam adjust screw on the control function is researched, which will play an important role in localization of manufactures of air suspension seat. In chapter six, by using the multi-body system dynamics theory and the software ADAMS, dynamics simulation model of the air suspension seat is built and the nonlinear elasticity characteristics of airspring is inputted to the digital model that makes the model more precise. The vibration absorption performance is simulated and tested. A practical available model and research method for designing air suspension seat is presented, which has significant theory meanings.Then the match method of airspring's stiffness and the vibration absorber damping coefficient is studied and the range of keeping vibration absorption performance of air suspension seat better is presented, which will support a vital basis for enterprises to choose air spring and vibration absorber for air suspension seat and will play an important role in localization of manufactures of air suspension seat. Chapter seven is the summarization of the paper, study contents andresults, the main research findings and innovations are mainly represented, as well as the study prospect from now on.