Study On The Anti-penetration Performances Of Aluminum Foam Sandwich Plate

Aluminum foam sandwich plate has many good characteristics, such as lightweight, high specific rigidity, high specific strength and good energy absorption ability. They are widely applied in high-tech domain, such as automobile industry, aerospace, shipbuilding, marine protection and so on. As an anti-impact composite material, it is inevitable to suffer from the impact loading of all kinds of missiles and projectiles. Therefore, only to master its anti-penetration performances, so can play its own protective ability.Firstly, closed-cell aluminum foam has been tested under the quasi-static compression condition, we could have obtained the constitutive parameters of aluminum foam. Secondly, obtain the correct constitutive parameters by the numerical simulation of the Q235 steel plate anti-penetration model, then summaried for relevant parameters on the anti-penetration to Q235 steel plate. Thirdly, based on the constitutive parameters of aluminum foam and steel plate, the finite element model of aluminum foam sandwich plate is established. And then study the impact process, the plastic deformation, the residual velocity and the energy absorption performances of sandwich plate. Finally, the parameters of the anti-penetration performances of the aluminum foam sandwich plate are studied, which provide the basis for the calculation of the anti-penetration characteristics and optimal design of the aluminum foam sandwich plate in different conditions. Specific contents are as follows:(1) The compression test of different aluminum foam densities under quasi-static conditions are carried out. The relationship between the elastic modulus, yield strength, yield platform length and the material densities of the aluminum foam materials are studied; the deformation and failure mode of the closed-cell aluminum foam under compression and the aluminum foam energy absorption versus densities are studied. Then using the theoretical formula to fit the experimental data of aluminum foam, the structure parameters of the aluminum foam compression constitutive model were obtained.(2) According to the anti-penetration performances of the steel plate in literature, the Q235 steel constitutive model is modified by Johnson-Cook model, using the LS-DYNA software to simulate the Q235 steel plate under the same conditions. Through the comparison of the experimental results, we make sure that the finite element analysis is reliable. We obtained the constitutive parameters of Q235 steel and provide the face-sheet's parameters of sandwich plate. The steel layering effect, the gap between the steel plates and the shape of the projectile on the anti-penetration performances are analyzed.(3) The corresponding simulation models are established according to literature of the parameters of aluminum foam sandwich plate. The numerical simulation is completed for the aluminum foam sandwich plate under different projectiles penetrating. The reliability of the finite element models are verified by comparing with the experimental data and the simulation results. Then based on the constitutive parameters of aluminum foam and the steel plate, the finite element model of the sandwich plate with the Q235 steel plate and the aluminum foam core is established. The failure patterns of the different parts of the sandwich plate are analyzed which impacted by projectiles. Compared the velocity time process and energy absorption process for the sandwich plate, which impacted by different projectile. The plastic deformation curves of the front face-sheet, back face-sheet and the foam core are compared. The effects of the impact velocity and the shape of the projectile on the plastic deformation, the residual velocities, and energy absorption properties of the sandwich plate are analyzed.(4) The parameters of the anti-penetration performances of aluminum foam sandwich plate are studied with the LS-DYNA finite element software. The effects of the face-sheet thickness, core thickness, core density, face-sheet combinations and the shape of projectiles on the penetration performances are analyzed. It provides the basis for the design of the anti-penetration characteristics and optimal design of the aluminum foam sandwich plate under different conditions.