| In order to improve the level of crash energy absorption of car and the safety performance of cars,reduce the casualties in the collision accidents, there a lot of researches have been carried out, which had been progressed many passive energy absorption mechanism,such as Progressive crushing type、Hydraulic damping type、Balloon type,and so on. But these kind of Energy-absorbing measures showed great limitations when are faced with some issues like the improving of the crash safety standards、the compatibility of vehicle to vehicle’s quality collision and stiffness.In my opinion,the direction of development of buffer system in the future will be the smart buffers which have variable stiffness and high energy absorption characteristics.Magnetorheological damping devices which designed base on magnetorheological technology have many advantages,such as adjustable damping force, fast response speed, simple structure, low energy consumption, etc.Magnetorheological technology increasingly mature and applied research in depth impact load,which provides a new direction and possibilities to control method of car crash safety.This technology has important academic value and practical significance to study of car crash safety.In this paper, according to the requirements of vehicle crash energy absorption and the characteristics of magnetorheological technology,the method of design and structure optimization of magnetorheological grease collision buffer with multi-channels based on magnetorheological technology was put forward.The main research works in this paper are as follows :(1)Basing on the present situation of the research vehicle collision safety, according to the automotive crash safety requirements and the characteristics of magneto rheological technology, the paper put forward the design method of multi-channel MRG buffer collision based on flow mode.(2)According to elastic-plastic mechanics of the material,in theory,the calculation formula of Corrugated pipe resistance on the elastic deformation and plastic deformation stage was deducted when under the axial compression loads. According to the rheology and electromagnetism, the specific structure and the working principle of the buffer and characteristics of magneto-rheological grease, the paper deduced thecalculation method of damping force of channel based on the constitutive model of Bingham fluid and The parallel plate flow model, the influence of the channel structure dimensions on the damping force was analyzed in this paper.(3)According to the characteristics of the vehicle crash and the structure of the buffer, the drop hammer type impact test system was designed,the impact test of the corrugated pipe was conducted, and analyzed deformation of the corrugated pipe,displacement time history,resistance time history,the relationship between resistance and displacement,The damping force and displacement.(4)Toke the calculation formula of buffer damping force as the basis,according to the goal that the bellows stiffness is minimized and the amount of compression is maximized, adjustable coefficient of channel damping force is maximized and the Strength requirements of the damper, MATLAB optimization toolbox was used respectively to optimize corrugated pipes and damping channel structure size in this paper.(5)The paper used analysis software ANSYS to respectively implemented collision simulation of the corrugated pipes before and after optimization, hydrodynamics simulation of damping channel before and after optimization.compared the Rigidity and The amount of compression of corrugated pipes,Analyzed the velocity and pressure distribution within the channel,then evaluated the performance of the original and optimized damper. |
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