Blast Resistance Of Multilayer Graded Lattice Sandwich Structures

The anti-explosion protection structures are not only vital in military applications,but also hold an important place in the chemical,petroleum and nuclear industries.At present,most of the anti-explosion protection structures based on solid plate structures.However,with the rapid development of science,technology and modern industry,finding a lightweight,high strength and multifunctional integrated structure has become the developing direction of research on anti-explosion protection structure.From this point of view,the lattice sandwich structure with ultra-light weight,high specific strength and multi-functional properties has become a research hotspot.The existing experimental study found that under explosive loads the lattice sandwich structure has the panel extension,compression failure and shear failure of the core truss and other energy absorption mechanisms.In addition,its open topological configuration provides sufficient space for large plastic deformation of the core truss.This shows that the lattice sandwich structure has a great advantage in anti-explosion protection.The multi-layer lattice sandwich structure has better anti-explosion protection effect compared with the single-layer lattice sandwich structure.When the non-gradient multi-layer lattice sandwich structure is subjected to the explosion load,the deformation degree of every sandwich layer differs greatly,which enormously limits the blast resistance performance of the lattice sandwich structure.Therefore,in this paper,the dynamic mechanical response of multi-layer gradient lattice sandwich structure under the explosive load is designed and investigated.In this paper,ABAQUS finite element analysis software is used to simulate the dynamic mechanical properties of multi-layer gradient lattice sandwich structure by means of CONWEP explosive loading mode.First of all,four sorts of three-layer gradient lattice sandwich structure models are designed by adjusting the cross-section side length of the lattice truss,which are the strong-weak interphase model,the weak-strong interphase model,the fading model and the crescendo model,respectively.In this study,the maximum deflection of the back-sheet center,deformation energy of the core and the deformation of each layer of the gradient lattice sandwich structure under explosion with pyramidal and hourglass topologies are analyzed.The results show that,the blast resistance performance of the strong-weak interphase model and the crescendo model is obviously better than that of the non-gradient model,and the deformation energy of the first two layers of the strong-weak interphase model are fully utilized,which the relative density ratio between various layers is 50%,so that the third layer of the core and the back-sheet are protected well.Therefore,this kind of gradient model has the best blast resistance performance.The multilayer hourglass lattice sandwich structure shows the similar phenomenon as the pyramid lattice structure,the blast resistance performance of the strong-weak interphase model and the crescendo model is obviously better than the other models,the deformation energy of the first two layers of the strong-weak interphase model and crescendo model are fully utilized,so that the third layer of the core and the back-sheet are well protected.Under the same explosive load,the blast resistance performance of hourglass lattice structure is superior to the pyramidal lattice structure.Under different explosive loads,the results show that the higher explosive impact of high explosive charge in a certain range is the more sensitive to the relative density ratio between various layers.