Study On Energy Absorption Characteristics Of Metal Thin-walled Square Tube And Its Optimal Design

In order to reduce the damage of the train,the front end of the train is often protected by the buffer and energy absorption device.The metal thin-walled square tube has many advantages,such as simple structure,low manufacturing cost,small fluctuation of axial compression load,etc..In this paper,by means of theoretical calculation,finite element simulation and experimental analysis,a theoretical model for energy absorption of thin-walled square metal tubes is established,and its energy absorption characteristics are studied.The specific content of the study is as follows:A theoretical model of energy absorption and average load force of a thinwalled square tube under axial quasi-static compression is established.Based on Mises yield criterion,the theoretical model of energy absorption and average load force of square metal tube under axial quasi-static compression is established,it provides guidance for the prediction of the energy absorption and the average load force in the axial compression of metal thin-walled square tubes.The energy absorption characteristics of different variable metal thin-walled square tubes under quasi-static compression are analyzed.The evaluation criterion of the energy absorption characteristics of the square metal tube in axial compression is proposed.The effects of different materials,wall thickness,height and cell size on the energy absorption characteristics of thin-walled square tubes filled with aluminum honeycomb were analyzed.The Bent Square pipe with induced deformation structure is put forward,and the bent square pipe is optimized.Taking the energy absorption evaluation standard as a reference,the Bent Square tube structure which can enhance the energy absorption effect is put forward,the number of folding units m and the Bending Angle of the Bent Square tube are taken as the parameter variables,the specific energy absorption(SEA)and the compression force efficiency(CFE)are taken as the design goals,the parameters of the square pipe are sampled by the full factor experiment method,and the approximate model of the objective function is established according to the radial basis function.On the basis of this model,the pareto front solution sets of the design targets SEA and CFE are obtained by using the multi-objective genetic algorithm in Matlab,the structural optimization design of the Bent Square pipe is completed,and the correctness of the optimization result is verified by numerical simulation.In this paper,the energy absorption characteristics of thin-walled square tubes under axial compression are studied,which can provide reference and help for the design and application of passive protective devices in Rail Transit.