Numerical Simulation On The High-speed Penetration Resistance Of Porous Metal Sandwich Structure

Porous metal “sandwich”structure is composed of prodous metal core layer and metalskins, this structrues not only give full play to the advantages of each component’ material ofthe structure, but also to solve the weakness of materials, for example, low intensity and lowshear strength of the core material. Because of the structure has a good energy absorptionefficiency, shock absorption and impct resistance, so it has broad prospects in the field ofexplosion-proof, bullet-proof vests and lighr armor protection.In this paper, the numerical simulation method would be used to analyse the impactresistant ability of the honeycomb sandwich panel when wich is impact by the foamaluminum bullet; in order to prove the accuracy and credibility of the simulation results, wehad done the experiment that honeycomb sandwich panel impacted by the foam aluminumbullet as the simulation. Based on the finite element model, we had optimized design to thestructures paremeters honeycomb sandwich panel, and analyse the impact resistant ability tothe optimized honeycomb panel structure impacted by the steel bullet. The main works andresults of this paper as fllows:1. The impact load obtained by changing the density and the impact speed of the foamaluminum bullets. Through the simulaiton, we found that the deformation of the honeycombpanel changed with the chang of the impulse loaded. Before and after the panel be penetrateddestrution, the energy absorption of the components of the structure would be re-distribution.2. We had done the penetration experiment to the sandwich panel with the secondarylight gas gun. From the results of the experiment and the simulation, we compared therelationship between velocity of the bullet, and the penetration depth, and compared thedestruction of the honeycomb sandwich panel. Throngh comparison results, we found that theexperiments were agreed with the simulation results. The honeycomb panel was penetrated bythe foam bullet at the velocity250m/s when foam’s desity is1325kg/m~3.3. Optimized the parameters of the honeycomb sandwich structures, as the top piane andthe bottom plane, the cellular wall thickness and the thickness of the honeycomb core layerstructure, by using the orthgonal experimental method. Through the analysis, we found thatthe optimal structure has the different parameter combination to the different objective fuction.From the method evaluation fuction, we have got the parameter combination to the structure, the thickness of top surface and the bottom surface are0.4mm, the thickness of the cellularwall is0.6mm, the thickness of the honeycomb core is8mm.4. Analysis the resistance to the bullet penetration ability to the optimized structure byusing the simulation. From the relationship between the bullet’s intial velocity and theresidual velocity, we found that, near the limit velocity, the residual velocity increasing withthe intial velocity increasing, and when the bullet velocity greater than140m/s the residualvelocity increasing sraighit up. Through changing the bullet shap, the flat head bullet has thelowest residual velocity, the structure has the strongest ability to anti-the flat head bulletpenetration. We observed the influence of bullet’s impact angle to the bullet-proof abiliy ofthe structure through changing the impact angle, and found that when the bullet penertratedthe plate at the nomal incidence, the honeycomb sandwich panels has the weakest bullet-proof.Through simulation the impact at different location, we found that the panel has the weakestbullet-proof at the center point.