Explosion Resistance Performance Of Double Sandwich Plate Under Explosion Load

The sandwich structure has many merits such as light weight,high strength,good stability,good buffering and energy absorption,and good sound insulation performance.It is extensively used in a lot of fields such as building materials,auto parts,aircraft components and naval vessels.The honeycomb sandwich structure is a very important energy-absorbing structure,and the external sudden load is an important factor leading to the change of the mechanical properties about the sandwich structure.Multitude studies have shown that the core layer of honeycomb sandwich structure is the main energy-absorbing component,and the use of a multilayer gradient honeycomb sandwich structure can effectively improve the impact resistance of the structure.When the sandwich structure is loaded to a sudden external load,the easy compressibility of the honeycomb core layer can absorb most of the impact energy through greater plastic deformation.At present,there are few studies on the influence of the size parameters of the honeycomb core layer on the impact resistance of the double-layer sandwich structure.The research on the core layer parameters of the double-layer gradient sandwich structure needs to be further studied.This paper uses a simplified fiber-reinforced double-layer honeycomb sandwich panel.The entire double-layer sandwich panel consists of two fiber-reinforced metal laminate panel and two aluminum alloy honeycomb core layer.This paper analyze the explosion resistance performance of the double-layer honeycomb sandwich panel under different explosion loads by experiment and numerical simulation,this analysis include the dynamic response process,the deformation failure mode,the residual deflection of the back panel,and the energy absorption.This paper mainly studies the influence of the relative density of the core layer and the size of the core layer on the explosion resistance performance of the entire double-layer sandwich structure.First of all,the experimental research of the double-layer sandwich panel specimens were studied under different explosive loads by the ballistic impact pendulum test system(charge mass from 10 g to 20g).In addition to bullet holes damage,the front panel basically shows a large overall plastic deformation under the action of a small impact load;and the front panel will experience tearing failure in the center area and accompanied by a certain indentation deformation under the action of a large impact load.And as the load increases,the degree of damage and deformation will increase.When the explosion load is small,the core layer exhibits large plastic deformation as a whole;with the load increasing,the core layer will experience local compression deformation failures and even penetration failures of the entire core layer.When the back panel is not damaged,it is basically shown the overall plastic deformation of different degrees,and the back panel will undergo local convex deformation under the action of a large load.Based on experimental research,the finite element analysis software ABAQUS was further used to create a numerical analysis model,and the numerical simulation was performed under the same explosion load.The results of the experiment and numerical simulation are compared to verify the accuracy of the finite element model.In order to study the effect of the size parameters and the initial relative density of the upper core layer on the explosion resistance performance of the entire double-layer sandwich panel,the size parameters and structure of the lower core layer were kept consistent with the experimental specimen size.In order to obtain a double-layer sandwich panel with a consistent relative density,the paper increased the length of the honeycomb side of the upper core layer and the wall thickness of the hole in the same proportion.On this basis,in order to increase the relative density of the upper core layer,the honeycomb wall thickness of the upper core layer was increased,and the relationship between the size parameters and the relative density of the core layer with the explosion resistance of the double-layer sandwich panel was analyzed.It is found that keep the same honeycomb side length of the upper and lower cores of the double-layer gradient sandwich structure has better explosion resistance performance under different explosive loads,and the relative density of the core layer is directly related to the explosion resistance performance of the structure.In order to further study the advantages and disadvantages of the relative density ratio of the core layer of the double-layer gradient sandwich panel under different explosive loads,a doublelayer gradient sandwich panel with different ratios of the relative density of the upper and lower core layers was further established.The results show that under the impulse generated by different explosive loads,the use of a double-layer gradient sandwich panel with a core layer relative density ratio of about 3:1 can optimize the anti-explosive performance of the sandwich structure,further it can provide a certain reference for the use and design of sandwich panels in different conditions in engineering.