Analytical and numerical Study of the Penetration Depth of Double Nose Rigid Projectiles in Concrete Targets by Considering the Friction

In this study the kinetic projectile with double nose in concrete targets by considering the velocity effect on friction between projectile and target is investigated. Numerical methods and finite element solution were used to calculate the depth of the penetration. In the numerical solution method, by integrating the stress at the nose surface and calculating the force on the nose of the penetrating projectile, the penetration depth of the projectile was calculated using Newton's second law and numerical methods were used to solve the resulting differential equations. In the finite element method, the Concrete damaged plasticity structural model was used to model the behavior of concrete, and in both the finite element method and the numerical solution method, the static-dynamic exponential reduction model is used to model the frictional force on the projectile. In order to develop the penetration depth equations, the parameters and equations related to the exponential friction coefficient have been considered and the two-step nose penetration depth equation has been developed by considering different parameters. To validate the proposed model, the results of experimental projectile penetration tests with the shape of the nose of other researchers have been used. Considering the effect of speed on the coefficient of friction between the projectile and the target has significantly increased the accuracy of speed calculations in this research.