Study On Energy Absorption Characteristics Of Porous Structure Based On 3D Printing

The high porosity of ultra-light porous metal materials makes it unique and versatile,including light weight,high specific strength,high specific stiffness,impact resistance,noise reduction and heat dissipation,and multi-functional integration.It is widely used in automobiles.Energy dissipating devices for vehicles such as rail transit,aircraft and ships.The wide application of ultra-light porous metal materials not only greatly reduces the demand for conventional energy,but also reduces environmental pollution.Honeycomb structure is a typical ultra-light porous metal material.It has a special deformation mode during compression.It absorbs a large amount of energy through the plastic deformation of the cell wall and mitigates the impact force.It has been widely used in packaging,protection of important equipment and structures.Internal filling and military engineering.Therefore,studying the energy absorption characteristics of honeycomb structures,optimizing the honeycomb structure,and improving the energy absorption capacity of honeycomb structures have always been an important research topic.In this paper,the topology optimization of a typical hexagonal honeycomb structure is carried out,and then a series of researches on the energy absorption characteristics of the optimized honeycomb structure are carried out.The main work includes:(1)Optimize the typical hexagonal honeycomb structure,divide each side into two segments,and replace it with an arc of 150 degree central angle;digitally model the cellular topology and print out the entity with a German EOS laser metal printer.Contains a single cell body and the entire entity unit.The in-plane,out-of-plane and single cell axis axial quasi-static compression experiments were performed on the hexagonal honeycomb structure and the optimized honeycomb topology.The force-displacement curves of the two honeycomb structures were compared to calculate the energy absorption and energy absorption efficiency of the two honeycomb structures.The results show that the energy absorption and energy absorption efficiency of the optimized honeycomb structure are significantly improved both in-plane and out-of-plane.(2)The energy absorption characteristics of the cellular topology under the same velocity are calculated by numerical simulation.The results show that the cellular topological structure has obvious strain rate effect under in-plane compression,and the energy absorption and energy absorption of the structure increase with the increase of velocity.The efficiency is improved;the wall thickness is changed at the same speed,and the influence of wall thickness on the energy absorption characteristics is studied.The results show that the wall thickness affects the energy absorption and energy absorption efficiency.As the wall thickness increases,the energy absorption Both the energy absorption efficiency and the specific energy absorption are improved,indicating that appropriately increasing the wall thickness of the structure is beneficial to improving the energy absorption characteristics of the structure.At the same time,the effect of velocity on the deformation mode of the honeycomb structure after optimization is studied.The results show that the honeycomb structure is deformed at a low speed,resulting in 45-degree shear failure,and deformation occurs on one side of the structure,corresponding to the first platform stage;On the other hand,the other side begins to deform,corresponding to the second stage of the platform;at high speed,there is a distinct localized deformation zone in the specimen block,and the deformation zone will continuously propagate one layer after another until the boundary is fixed.(3)Calculating the energy absorption characteristics of the axial compression of single-cell thin-walled tubes with honeycomb topology at the same speed by numerical simulation,and studying the influence of strain rate on the energy absorption characteristics of the structure.The results show that the thin-walled tube structure has obvious strain.Rate effect,as the speed increases,the energy absorption and energy absorption efficiency increase;the wall thickness is changed at the same speed,and the influence of wall thickness on the energy absorption characteristics is studied.The results show that the wall thickness is effective for energy absorption and energy absorption.The effect is increased.As the wall thickness increases,the energy absorption efficiency and the specific energy absorption increase,which indicates that the proper increase of the wall thickness of the structure is beneficial to improve the energy absorption characteristics of the structure.At the same time,the deformation modes at different speeds and different wall thicknesses are studied.It is found that the different deformation modes will be different,and the wall thickness does not have much influence on the deformation mode.(4)The energy absorption characteristics of the cellular topology under the same speed are calculated by numerical simulation.The results show that the cellular topology has obvious strain rate effect,and the energy absorption and energy absorption efficiency increase with the increase of speed;The wall thickness was changed at the same speed,and the influence of wall thickness on the energy absorption characteristics was studied.The results show that the wall thickness has an effect on the energy absorption and energy absorption efficiency.With the increase of wall thickness,the energy absorption and energy absorption efficiency and specific absorption The energy can be improved,indicating that appropriately increasing the wall thickness of the structure is beneficial to improving the energy absorption characteristics of the structure.At the same time,the influence of velocity on the deformation mode of the optimized structure is studied.The results show that the velocity has little effect on the deformation mode,but the wall thickness has a great influence on the deformation mode.When the wall thickness is thin,it collapses from the middle when compressing.Buckling occurs when the wall thickness is thick.