An SPH model reconstruction framework with fragment mapping method for multiplate structure hypervelocity impact simulation

Smoothed Particle Hydrodynamics (SPH) method is widely used in hypervelocity impact analysis, but it is computationally inefficient for common multiplate structures, such as multi-shock, mesh double-bumper, and stuffed shields. To improve the efficiency and accuracy of the SPH method, a reconstruction framework is proposed, including a fragment identification method, a fragment mapping method, and a sequential modeling and simulation approach. In the reconstruction framework, the total impact simulation of a multiplate structure consisting of n plates is decomposed into n individual impacts on each plate. To reduce the computation for each impact, a fragment identification method and a fragment mapping method are developed. Fragments generated from the impact with the i-th plate (i < n) are identified and mapped to the near positions in front of the (i + 1)-th plate using a linear motion algorithm. To reduce the total computation time, a sequential modeling and simulation approach is introduced, only the fragments from the i-th impact and the SPH model of the (i + 1)-th plate of the multiplate structure are reconstructed and simulated sequentially, excluding the other plates. The results show a significant improvement in computational efficiency compared to the traditional SPH method. For a three-layer structure with a 100 mm spacing, the efficiency is 59.2 times larger, while for a double-layer structure with a 350 mm spacing, the efficiency is 201.74 times larger. Moreover, the interactions between fragments are considered in the reconstruction framework, thereby the accuracy of the simulation is also improved.