The paper presents an energy iterative method to determine the second critical velocity by comparing the time histories of the kinetic energy and the buckling deformation based on the finite element model of the impac...The paper presents an energy iterative method to determine the second critical velocity by comparing the time histories of the kinetic energy and the buckling deformation based on the finite element model of the impact system. To design anti-impact structures of the thin-wall cylindrical tubes with this new method, the cost of the experiment can be considerably reduced. The feasibility and validity of this method are demonstrated by a dropping hammer experiment. In addition, this paper deals with the influence of constrained damping layers on the anti-impact capability and energy-absorption of thin-wall cylindrical tubes. Results show that the constrained damping layers make the energy-absorption and the anti-impact capability increased comparing with the naked tubes; the thickness of the damping layer should be restricted in a range, or else the anti-impact capability will decrease with the increase of the damping layer thickness; for the constrained layer, the anti-impact capability will increase with the augment of its thickness.展开更多
A new type of thin-walled circular tubes(CTs),which is inspired by the bamboo with highly-efficient energy absorption(EA)capability,was proposed and designed for the potential application of the energy absorber of rai...A new type of thin-walled circular tubes(CTs),which is inspired by the bamboo with highly-efficient energy absorption(EA)capability,was proposed and designed for the potential application of the energy absorber of rail vehicles in this study.And then,the axial crushing behavior and crashworthiness of the bamboo-inspired bionic tube(BT)were experimentally and numerically investigated,compared with the single CT and foam-filled tube(FT).The typical crushing responses(e.g.,deformation mode,load-displacement response,energy absorption,and strain distribution)and quantitative crashworthiness indicators(EA,SEA,FP,Fm,and CFE)of these three types of CTs were presented and discussed.Effects of impact velocity and foam relative density on the crashworthiness of tested tubes were also explored.The experimental and simulation results show that the BT specimen exhibits the best capability of load-carrying,energy absorption,and crashworthiness among three types of tubes.Compared with the CT specimen,the EA value of BT specimens increased by 93.1%,while the corresponding Fm value raised from 74.2 kN to 143.4 kN.展开更多
文摘The paper presents an energy iterative method to determine the second critical velocity by comparing the time histories of the kinetic energy and the buckling deformation based on the finite element model of the impact system. To design anti-impact structures of the thin-wall cylindrical tubes with this new method, the cost of the experiment can be considerably reduced. The feasibility and validity of this method are demonstrated by a dropping hammer experiment. In addition, this paper deals with the influence of constrained damping layers on the anti-impact capability and energy-absorption of thin-wall cylindrical tubes. Results show that the constrained damping layers make the energy-absorption and the anti-impact capability increased comparing with the naked tubes; the thickness of the damping layer should be restricted in a range, or else the anti-impact capability will decrease with the increase of the damping layer thickness; for the constrained layer, the anti-impact capability will increase with the augment of its thickness.
基金This work was supported by the National Natural Science Foundation of China(Grant No.12122211).
文摘A new type of thin-walled circular tubes(CTs),which is inspired by the bamboo with highly-efficient energy absorption(EA)capability,was proposed and designed for the potential application of the energy absorber of rail vehicles in this study.And then,the axial crushing behavior and crashworthiness of the bamboo-inspired bionic tube(BT)were experimentally and numerically investigated,compared with the single CT and foam-filled tube(FT).The typical crushing responses(e.g.,deformation mode,load-displacement response,energy absorption,and strain distribution)and quantitative crashworthiness indicators(EA,SEA,FP,Fm,and CFE)of these three types of CTs were presented and discussed.Effects of impact velocity and foam relative density on the crashworthiness of tested tubes were also explored.The experimental and simulation results show that the BT specimen exhibits the best capability of load-carrying,energy absorption,and crashworthiness among three types of tubes.Compared with the CT specimen,the EA value of BT specimens increased by 93.1%,while the corresponding Fm value raised from 74.2 kN to 143.4 kN.
