The Code Development Of Smoothed Particle Hydrodynamics And Its Application In Collision And Impact

The smoothed particle hydrodynamics(SPH) method is a meshfree method, in which particles with material information are used to represent the solution domain. SPH can get rid of the constraints of grid. Compared with traditional grid method, SPH has unique advantages, particularly suited to simulate collision, impact, erosion problems. The meshless, adaptive and lagrangian nature of the SPH method make it a hot topics in the study of impact dynamics and engineering application.Firstly, the basic theory of SPH is summarized: kernel function approximation and particle approximation, the SPH approximate expression of the derived function of arbitrary function is given. The SPH formula of material with strength is deduced, considering the solid material constitutive, equation of state(EOS), artificial viscosity etc. In addition, the tensile instability and fixed boundary problems are introduced.Secondly, combined with the integral mode in Liggghts, the SPH program is developed with material strength, which can be applied to solid materials. In the self-complied code, different EOSs and kernel functions can be chosen for second or third dimension simulation; To validate the self-complied code, the comparison of the simulation of tension, compression and bending with the theoretical results were done. It showed that the self-complied code well reproduced the theoretical results. The simulations of Taylor collision and double aluminum’s collision showed that it can precisely simulate the collision and impact problems.Finally, several collision and impact problems are simulated, including the ball bead projectile impact the monolayer plate, the spherical projectile impact the single target board and the Tungsten projectile impact the steel-aluminum alloy composite target plate, respectively. The deformation in the process of impact, the residual velocity of the projectile and the size of broken hole are analyzed. For the composite target plate, the deformation and failure of different layers also compared. Therefore, the self-complied code showed its ability in simulating varied impact problems.