Study On Car Impact Absorber Performance Evaluation And Performance Of Magnetorheological Impact Absorber

With the progress of science and growth of economy,automobile has become an indispensable transportation for people,but the casualties caused by traffic accidents compelled vehicle safety research to reached unprecedented heights.Automobile collision buffers can reduce the damage of collision impact to occupant and pedestrian in the vehicle to some extent,and it has become an important research direction in the field of passive safety of automobiles.However,many kinds of collision bumpers,varies application environment,different damping performance resulted in lacking of evaluation of crash absorbers' damping performance.Lots of researches on crash absorbers and other parts were studied by many scholars,including foam crushing-type,thin-walled structure,hydraulic suction,airbag and so on,but these devices' damping coefficient is not adjustable,only can work efficiently in the specific impact conditions.The crash absorber,based on magneto-rheological technology,has outstanding figures,such as adjustable damping,high-speed collision response,good adaptability,low consumption and has been applied in suspension systems.Even the magneto-rheological crash absorber has many advantages and great prospects,there are still many problems to be overcome,particularly subsidence and shear-thinning of high speed impact phenomena,and so on.Therefore,in order to find out the key factors to devices' performance,establish performance evaluation indexes,further researches are needed.,and these researchers will help to expand the field of automotive passive safety research,and will provide a solid theoretical and practical support to ensure occupant safety.Based on the crash absorbers' theory,and figures of vehicle crash,the evaluation system to absorbers was established,and did evaluation to this kind of MR absorber according the evaluation system.The details of research are as following:1.Emphasized the importance of establishing a comprehensive evaluation system,and then presented the aim and contents of this research,after analyzing the present situation of study on absorbers properties and existing performance evaluation systems' faultiness.2.Combined with the application requirements of vehicle crash absorber,the evaluation system was founded,including acceleration characteristics,load characteristics,stroke efficiency,response characteristics and adjustment coefficient five different evaluation index.Besides,the theory analysis about evaluation index with absorbing performance.3.The size and the channel structure of the MRF damper are optimized by analyzing the experimental results.Based on the drop hammer impact test,a series of impact tests were carried out on the magneto rheological damper.According to the test data,some analysis on deformation process,impact force timing and acceleration timing were made4.Calculated out the value of different evaluation index of varies collision condition,and compared relationship of index with different collision heights and current,then analyzed the main factors to evaluation index.The above research showed that the performance evaluation index of the absorbers can be applied to the evaluation of the performance of magnetorheological buffers,and the main factors influencing the buffering performance of magnetorheological buffer can be clarified by evaluating and analyzing,and can provide guidance for optimizing the structure of absorbers and improvement of impact testing system.