Numerical Simulation Of Explosive With Cavity Liners Penetration Into Honeycomb Plate Based On Material Point Method

Equipped with a protective bottom plate,armored vehicles can effectively defend against penetration brought by the explosive cover.But they will become heavier and heavier.Therefore,it is important to reduce the weight of the shield without affecting its ability to resist penetration.As a new type of engineering material with relatively small density,high strength,strong energy absorption ability and strong cushioning ability,honeycomb material can effectively reduce the quality of the protective plate.The penetration process of charge cover will involve large deformation of material.If the numerical simulation of traditional finite element method is used,grid distortion will appear.Instead,material point method(MPM)is a new meshless method which is suitable for solving this kind of problem.So in this paper,the numerical simulation of the process of explosive penetration into honeycomb plate is studied based on the material point method.Through the weighted allowance method,the governing equation of MPM and its discrete scheme were derived.The explicit MPM scheme for solving the penetration problem of explosive with charge cover was established.The flow chart of the realization process of the explicit MPM is given.The MPM program is programmed through FORTRAN language to simulate the penetration process of the explosive with charge cover into the plate.The results calculated in the simulative process of penetrating 45~#steel plate with explosive cover are in good agreement with the finite element calculation results in the literature,which verify the validity and feasibility of the MPM in simulating the penetration of explosives into the plate with charge type cover.The numerical simulation of explosive penetration into honeycomb plate was carried out.The influences of different parameters(shape of honeycomb plate,wall thickness of honeycomb plate and size of honeycomb plate)on penetration ability of explosive with explosive cover are discussed.The results show that honeycomb panel shape(round honeycomb panel,triangle honeycomb panel,hexagonal honeycomb panel)can effectively play a protective effect,and regular hexagon honeycomb panel is the lightest;With the increase of the wall thickness of hexagonal honeycomb panels,the maximum penetration depth of the shell decreases,while the relative density of honeycomb panels increases.Combined with the maximum penetration depth and relative density,the effect of wall thickness of honeycomb panels on the quality of protective panels firstly decreases and then increases,and the weight is the lightest when the wall thickness is about 2.3mm;With the increase of honeycomb size of hexagonal honeycomb plate,the penetration depth increases,the relative density decreases and the weight decreases.The relative density,mass ratio and maximum central penetration depth of honeycomb plate and solid plate were selected as test indexes,and honeycomb shape,wall thickness and honeycomb size were selected as test factors,the orthogonal test of L9(3 ~3)was established.Through range analysis,it can be concluded that the combination of hexagonal honeycomb panel whose wall thickness is 2mm and size is 8mm has the greatest influence on the quality of the protective panel under the test condition.According to variance analysis,the significant level relationship of factors under test conditions is as follows:honeycomb shape>honeycomb panel thickness>honeycomb size.The numerical simulation of explosive penetration into honeycomb plate with charge type cover studied in this paper provides a new method and research idea for the study of explosive penetration into honeycomb plate with charge type cover,which provides certain guiding significance for the selection and research of protective plate of armored vehicle,meanwhile,it expands the application scope of MPM.