Study On Energy Absorption Characteristics Of Hexagonal Multi-Cell Train Anti-Creeper With Local Surface Nanocrystallization

Train operation safety mainly includes active safety and passive safety.Active safety is the ability of train to avoid accidents;Passive safety means that when a collision accident occurs,the plastic deformation of the energy-absorbing device of the train is used to dissipate the huge impact kinetic energy,so as to minimize the impact damage to personnel.As an important part of the passive safety system,the anti-climbing device plays an important role in the collision accident.In this paper,the energy absorption characteristics of hexagonal multi-cell shell under the axial impact of falling hammer are explored by taking the energy absorption part of crush anti-climber of rail vehicle as the breakthrough point.In this paper,the local surface nanocrystallization technology is applied to the hexagonal multi-cell shell to induce good buckling deformation and improve the energy absorption characteristics of the hexagonal multi-cell shell by changing the material yield limit without changing the geometric structure and size of the hexagon multi-cell shell.Based on the software LS-DYNA,the finite element impact model of hexagonal multi-cell shell was calculated.The buckling deformation process was viewed in the LS-Prepost software,and the impact loaddisplacement curve was derived in turn,and the energy absorption evaluation index was calculated,so as to comprehensively analyze the energy absorption characteristics of hexagonal multi-cell shell under various working conditions.Firstly,the energy absorption of hexagonal single cell and multi-cell shell without nanocrystallization and that of hexagonal single cell and multi-cell shell with full nanocrystallization were studied comparatively,and it was found that the energy absorption performance of the former was better than the latter;Compared with the non-nanocrystallized hexagonal multi-cell shell,the specific energy absorption and impact force efficiency of the full-nanocrystallized hexagonal multi-cell shell is greatly improved,and the maximum peak load is also significantly improved.Secondly,the energy absorption of hexagonal multi-cell shells with different configurations of circumferential local surface nanocrystallization is studied,including four different configurations of symmetrical inner and outer shells,symmetrical inner and outer shells staggered,asymmetrical inner and out shells same and asymmetrical inner and out shells staggered.On this basis,the effect of the number of nanocrystalline ribbons on the energy absorption characteristics of antisymmetric and symmetric hexagonal multi-cell shells was studied.The simulation results show that the annular local surface nanocrystallization layout can effectively improve the specific energy absorption and impact efficiency of the hexagonal multi-cell shell,and can greatly reduce the maximum peak load of the hexagonal multi-cell shell compared with the full nanocrystallization;And the energy absorption of the hexagonal multi-cell shell is affected by the increase of the number of nanocrystalline ribbons under different nanocrystalline layouts.Finally,the influence of different nanoscale layouts in the partition section on the energy absorption of hexagonal multicellular cell shells is explored,which provides a new idea for the design and research of the energy absorption department of the crushing anti-creeper.