Numerical Simulation Of Composite Armor Anti-penetration Using Three-dimensional Smoothed Particle Hydrodynamics Method

Composite armor with good mobility and a strong ability of anti-penetration can protect bullet-proof vests,armored vehicles and aircraft from the ballistic threats. Anti-penetration of composite armor relates to the projectile and target nonlinear characteristics such as large deformation, damage evolution,tear and splash are very complex impact dynamics problem.Therefore, study of anti-penetration properties of composite armor by the impact loads has important significance for scientific research and engineering application.Comparative theoretical study and experimental research, numerical simulation has advantages of low-cost high-performance,easy operation and non-objective etc.Smoothed Particle Hydrodynamics(SPH)is a pure Lagrangian particle method, the material properties of the particles through a discrete computational domain, different materials,the particles constitute a natural interface.The calculation does not require the use of the background grid, avoid numerical problems caused by distortion,and easy to incorporate a variety of constitutive relations.So that it is easy to simulate the large deformation,damage evolution,fragmentation and splash problems of composite armor.The main work of this thesis includes the following aspects:First of all,a three-dimensional smoothed particle hydrodynamics code,3DSPH, is developed.The Johnson-Cook material model,the Mie-Gruneisen state equation and Tillostson state equation are incorporated into computations.The code is validated by the numerical example of Taylor shot impact problem and the spherical projectile hypervelocity impact on thin plates problem.Compare the SPH simulation results with the experimental ones as well as the results of other procedures to verify the correctness of the program.The characteristic of perforation and the debris cloud formation is also studied.Secondly, The Johnson-Holmquistâ…¡material model is incorporated into 3DSPH code. The SPH simulation results of three typical cases compared with the theoretical ones.It concluded that the 3DSPH procedure is well suited for the ceramic material. Furthermore,ceramic damage evolution under impact loads is studied.Finally,SPH simulation of normal and oblique ballistic impact on ceramic-metal composite armor is carried out.The numerical results agree well with the experiment ones.Study of the projectile erosion,ceramic fragmentation and metal back plate tear. The anti-penetration characteristic of ceramic-metal composite armor by projectile obliquity and ceramic-metal thickness ratio is also discussed.Furthermore,Reveal the mechanism of penetration to forecasting ceramic composite armor anti-penetration characteristic and making optimization design.