Study On The Performance Of Composite Armor With Aluminum Foam Resisting To The Jet Penetration

With the development of the new materials and structures of armor protection,the new sandwich composite armor has been paid more and more attention by researchers,foam aluminum material because of its light,high strength,toughness,and good energy absorption properties,often used in sandwich structure,so it has important practical significance to study the composition of new composite structure containing foam aluminum.In order to study the anti-penetration performance of the new composite armor,this paper firstly studies the jet penetration performance of the foam aluminum composite armor from the theoretical level,and then simulates the composite armor based on ANSYS/LS-DYNA software.The main contents are as follows several aspects:(1)The jet penetration resistance of foam aluminum composite armor is studied by using stress wave propagation and Kelvin-Helmholtz fluid instabilities.The results show that foamed aluminum can reduce the particle velocity of composite armor plate,and effectively attenuate the peak of stress wave,and has strong anti-penetration performance.The theoretical analysis can predict the interference tendency of the composite armor to the jet under the different surface,the back plate material,the different thickness and inclination angle,and provide the theoretical basis for the optimization of the aluminum foam composite armor structure.(2)By ANSYS/LS-DYNA software,the performance of anti-linear jet penetration of foam aluminum composite armor was simulated by choosing different materials of panel and back plate.The results show that the penetration resistance and the whole energy absorption of the foam aluminum composite armor structure are not only related to the strength of the cover material,but also to the order of the different strength materials.From the aspects of structural lightweightness,anti-jet penetration performance and energy absorbing capacity of foam aluminum composite armor,the front panel is made of ceramic material and the backplate is made of aluminum alloy,that is,the composite armor structure composed of ceramic/aluminum foam/aluminum alloy is preferred.(3)The simulation study was used to analyze the armor construction(ceramic/aluminum foam/aluminum alloy).The energy absorption rule,residual velocity of jet head,and protective capability were investigated at the different aluminum foam sandwich thickness,the thickness of the front and back plate under the same thickness of the composite armor,and composite armor angle.Results show that within the same angle,when the thickness of aluminum foam is increase,the particle velocity of back plate of composite armor can decrease by negative exponent rule.Within the same thickness of aluminum foam,when the angle is increase,the protective capability of aluminum foam and armor structure canincrease firstly,and then decrease.It shows that the aluminum foam thickness with 2.4 mm and composite armor angle at 20° can give the best performance for composite armor structure to resist to the shaped charge jet penetration.Furthermore,the thickness of the plate is very important to enhance the anti-penetration performance of the composite armor.When only different layout methods are used,the difference of penetration performance between interval type and contact type composite armor is small.(4)In order to optimize the ceramic/foam aluminum/aluminum composite structure.The residual velocity of jet head,energy absorption rule,stress-wave attenuation,and jet instability were investigated at the same surface density,the different combinations of front-back plate thickness ratios K and aluminum foam sandwich thickness.Results show that within the same thickness ratio K,when the thickness of aluminum foam is increase,the particle velocity of back plate and stress-wave peak value of composite armor can decrease by negative exponent rule.Within the same thickness of aluminum foam,when the thickness ratio K is increase,the absorbed energy of aluminum foam and armor structure can increase firstly,and then decrease.It shows that the aluminum foam thickness with 2.4 mm and thickness ratio between 1.25 K can give the best performance for composite armor structure to resist to the shaped charge jet penetration.