Numerical modeling of fragment flight dynamics

To study the flight dynamics of fragments, the following input data are considered: initial coordinates, velocities, air density, the fragment’s exposed area, drag coefficient, and mass. The parameters for the fragmentation process are determined through experimental studies and finite element analysis of the natural fragmentation of a high-explosive projectile. The simulation of the natural fragmentation of an explosive projectile shell leverages the finite element method, and stochastic failure theory is applied using the Ansys Autodyn software. The point mass trajectory model is employed to predict the trajectory of a fragment moving under the impact of drag and gravitational force. In the current study, the main focus was on the development of the methods and tools for implementing trajectory models with varying drag coefficients for different flow speeds. Different approaches for determining drag coefficient are discussed. The nonlinear trajectory model was converted to a linear system of differential equations by employing quasi-linearization. The linear system of differential equations was solved using the Haar wavelet method. The fragment trajectory model with improved accuracy can be considered as the final result of the study.