Study On Energy Absorption Characteristics Of Glass Fiber Thin-walled Circular Tubes Used In Rail Transportation

With the development of rail transit industry,more and more lightweight materials are used in passive safety protection devices.Resin matrix is a kind of composite material with low density,high strength and high energy absorption efficiency.Because of its complex energy absorption mechanism and special application conditions,the application of single axial crushing is very limited,resulting in less engineering application as a buffer energy absorption material.Referring to many engineering requirements and considering the energy absorption characteristics of resin matrix composites,the failure modes and control of glass fiber thin-walled circular tubes are studied in this paper.By placing the glass fiber thin-walled tube in the failure inducer,when the impact load acts axially on the outer end portion,the other end is extruded by the inner bulge structure of the inducer during the retreat,and the energy is absorbed through the extrusion.Based on this energy absorbing structure,this paper mainly conducts the following research:Firstly,according to the factors such as the layup angle of the glass fiber thin-walled circular tubes,the number and height of the inducer and the loading speed of the outside,the performance of glass fiber thin-walled circular tubes under different influence factors was obtained by the drop hammer dynamic impact test.using control variable method,and the failure modes and energy absorption characteristics of glass fiber thin-walled circular tubes were compared and analyzed.Secondly,based on the finite element software ABAQUS,the analysis model of energy absorption structure is established,and its performance parameters are obtained through material mechanics test.Then,the simulation and test results of glass fiber thin-walled circular tubes are compared and analyzed to verify the reliability of finite element software simulation analysis;On the basis of the above research,the structural form of the energy absorbing structure is simulated and optimized,and the mathematical relationship between the outer diameter,wall thickness and the height of the bulge is analyzed.Finally,according to the technical requirements of a line train for passive safety protection devices,a passive safety device with a glass fiber thin-walled circular tube as the energy absorbing element is designed,and its vertical bearing capacity and longitudinal bearing capacity are analyzed,which provides design basis and reference for future research on passive safety protection device based on glass fiber thin-walled circular tube.In this paper,the energy absorption structure of glass fiber thin-walled circular tube under the action of inducer is systematically studied.The main factors affecting the failure of energy absorbing structures are analyzed by the drop hammer impact test.Based on the finite element software ABAQUS,the sensitivity parameters affecting the energy absorption efficiency of glass fiber thin-walled circular tubes are optimized and analyzed.The empirical formulas among the parameters such as outer diameter,wall thickness and bulge height of the inducer are established.Finally,based on the above analysis results,a passive safety protection device applied to a railway train is designed.In this paper,the study of buffer energy absorption characteristics of glass fiber thin-walled circular tubes under the action of inducer is a pioneering research topic in China,which provides theoretical basis and technical support for the application of composite materials in the field of passive safety protection for rail,automotive and aerospace.