Numerical simulation of impact-induced mechanical behavior of the PTFE/Al/W reactive materials

Two-dimensional simulation models are established to investigate the impact-induced mechanical behavior of the PTFE/Al/W reactive materials. Random distribution of the metal particles and mesh generation of the specimen are obtained by using ANSYS parametric design language. Moreover, based on the experimental results of the Hopkinson bar, the loading curve in the simulation is simplified. Influences of the tungsten particle size, the particle distribution, and the loading strain rate on the mechanical behavior are analyzed by ANSYS/LS-DYNA. The results show that local severe deformation of the polytetrafluoroethylene (PTFE) matrix is generally caused by extrusion and slippage of the metal particles. The generation, growth, and interaction of the cracks are then induced gradually. Finally, many macrocracks form and the specimen dramatically fractures. Results also show that the local deformation of the PTFE matrix, deformation outline, and crack distribution are significantly influenced by the tungsten particle sizes and the particle distribution. In addition, with a decrease in the loading strain rate, the time for initial crack generation gradually delays and the deformation severity of the PTFE matrix shows a decrement.