Numerical Study On Impact Resistance Of Periodic Porous Structure

Due to its low density and high strength,porous structure is widely used in engineering protection fields such as energy absorption,noise reduction and shock absorption.Compared with the bare porous structure,sandwich plate structure composed of metal panel and porous structure core has the characteristics of high specific strength,high specific stiffness,good energy absorption characteristics,and can resist large impact.It is widely used in aerospace,vehicles,ships and other fields.At present,the research on the mechanical properties of random porous structures under impact has been widely carried out,but the research on periodic porous structures is not much,especially the sandwich composite structure with periodic porous structure as the core.Compared with random porous structure,periodic porous structure has controllable cell shape,strong designability and more stable mechanical properties.Therefore,it is significant to study the mechanical properties of periodic porous structure and sandwich plate with periodic porous structure as core.The main research work of this paper includes:1.The effects of loading speed and relative density on the deformation mode,densification strain,plateau stress and energy absorption of periodic porous structures are analyzed by using ABAQUS,a nonlinear display dynamics subroutine.The numerical results show that the periodic porous structure presents different deformation modes under the influence of loading speed,but it is almost not affected by the relative density.The platform stress,densification strain and energy absorption of the two structures increase with the increase of loading speed,but the energy absorption capacity of face centered cubic structure is better than that of body centered cubic structure under high speed loading.Under high-speed loading,the two kinds of porous structures have stress fluctuations in the platform area,which is related to the deformation mode and cell shape.The comparative analysis of the mechanical properties of the two porous structures provides a reference for the selection and application of the two structures.2.The effects of loading speed,relative density and horizontal constant C on the impact resistance of p-type minimal curved surface structure under axial compression are analyzed.The numerical results show that the energy absorption capacity of porous structure increases with the increase of loading speed and relative density.The influence of horizontal constant C on the impact resistance of p-type minimal curved surface structure is complex.Compared with the cube structure,the p-type minimal surface structure has a larger densification strain and enters the densification stage later.3.The high-speed impact resistance of sandwich plates with p-type minimal curved surface as the core was studied,and the energy absorption mechanism of sandwich plates at different speeds was analyzed.The numerical simulation results show that the energy absorption and distribution mechanisms of the sandwich plates are different under different impact velocities.The panel is the most important component to resist the impact of punch.Increasing the panel thickness can significantly improve the impact resistance of sandwich panel,but considering the requirements of lightweight design,the panel thickness can't be increased infinitely.