Experimental And Simulation Study On Penetration Resistance Of Heterogeneous Composite Structures

With the increase of maritime security threats and the continuous improvement of ship design requirements,the research on ship structural penetration resistance has been paid more and more attention.Because of its excellent mechanical properties and lightweight advantages,heterogeneous composite structures become an effective way to ensure the strength of ships and realize structural lightweight.It is of great significance to carry out experimental and simulation research on the design of heterogeneous composite structures and their anti-penetration performance for optimizing ship design and improving the anti-penetration capability of ship structures.This thesis selected materials representing different properties and characteristics,including Q235 steel,6061-T6 aluminum,aluminum foam and rubber,respectively designed aluminum foam sandwich structure,rubber sandwich structure and aluminum foam-rubber heterogeneous composite structure,and carried out experimental and simulation research on their penetration resistance.Aiming at the problem of negative volume and large penetration deformation of aluminum foam and rubber,SPH-FEM coupling method was established,and the simulation coupling method was verified by experimental results.The main research contents are as follows:(1)The heterogeneous composite sandwich structure scheme was designed,and the mechanical properties of rubber,aluminum foam and other materials were obtained by using the Hopkinson pressure bar experiment device and quasi-static experiment.The constitutive parameters were obtained according to the stress-strain curve,especially for rubber materials.The key parameters C10 and C01 were obtained through the experiment,and the dynamic constitutive model of the materials was established.The material parameters are provided for the study of penetration resistance of the structure.(2)The SPH-FEM coupling method for structural penetration simulation analysis was established to realize the simulation study on the penetration resistance of single and double layer steel plates.The reliability of the coupling method was verified by comparing with the residual velocity,structural deformation and penetration resistance process measured by experiments.It shows that the established SPH-FEM can reflect and characterize the deformation and damage of the structure after the impact of the projectile body.(3)To complete the penetration resistance experiment and simulation research of aluminum foam sandwich panel.An experimental study on the penetration resistance of aluminum foam sandwich panels was carried out with a tank experimental device,and then a simulation model of aluminum foam sandwich structure was established based on the SPH-FEM coupling method,and the simulation analysis of the penetration resistance of the structure was carried out.The feasibility and accuracy of the simulation method in this thesis were further proved by comparison with the experimental results.The penetration resistance of aluminum foam sandwich plate under different projectile body penetration is analyzed by simulation,and the influence of panel and core thickness on residual velocity,deformation and failure mode of aluminum foam sandwich plate is discussed.(4)Carry out experimental and simulation research on penetration resistance of rubber sandwich structure.Aiming at rubber monolayer,rubber sandwich structure and rubber sandwich structure in the rear water area,the penetration resistance experiment and SPH-FEM simulation study of two kinds of rubber sandwich structures were carried out by using a tank experimental device,and the penetration resistance of rubber sandwich structure and the rear water structure under different projectile body penetration was analyzed.The influence of core layer thickness on residual penetration velocity,deformation and failure mode of rubber sandwich structure is discussed.(5)Aluminum foam core layer,rubber core layer and steel were combined to form a heterogeneous composite sandwich plate,and the penetration resistance of the heterogeneous composite sandwich plate was studied based on SPH-FEM coupling method.The effects of different core thickness,different core placement sequence and different projectile shape on the penetration resistance of heterogeneous sandwich panels are discussed.It can be concluded that under the same condition,the deformation of flat head projectile body is larger than that of hemispherical projectile body when it penetrates the same heterogeneous composite sandwich plate.At the same time,the anti-penetration performance of the heterogeneous sandwich plate is analyzed from the Angle of deformation and energy absorption,and it is concluded that the energy loss of the flat-headed projectile body is greater than that of the hemispherical projectile body when it penetrates the composite heterogeneous sandwich plate.