Fragment And Shock Wave Structure Of Helicopter Combined Numerical Simulation Research

First, the explosion FEM (finite element model) of blast-fragmentation warhead was bulit in the paper, and the initial parameters and the impulse spreading process of fragments and shock wave were analyzed. And the encounter positions of fragments and shock waves from the explosion of blast-fragmentation warhead was explored. Second, the influence factors of the encounter position were explored, just like warhead loading coefficient, single fragment weight and types of explosives and so on. At last, under the alone action of fragments, shock wave, and the combination action of two kinds kill elements, the destructive effect of helicopter rotor and fuselage on the encounter position of fragments and shock wave were calculated and analyzed by numerical simulation.The research results indicated that:The fragments and shock wave formed by the typical blast-fragmentation warhead explosion met in the position being far away2.5m from explosive center (about12.6times charge diameter). The encounter position of fragments and shock wave had been influenced by the warhead loading coefficient, the single fragment mass, and the types of explosive charge. With the warhead explosive loading coefficient increasing, the encounter distance of fragment and shock wave to the explosive center was shorter, and when the explosive loading coefficient increased by31%, the encounter distance of fragment and shock wave to the explosive center decreased by11.5%. The increase of explosion heat and detonation velocity corresponded the increase of explosive loading coefficient, so the encounter distance of fragments and shock wave to the explosive center became shorter. Under the condition of the same explosive loading coefficient, the encounter distance of fragments and shock wave to the explosive center was shorter with the single fragment mass, but the effect was not significant.On the encounter position of fragments and shock wave, under the alone action of fragments element, the helicopter structure was caused perforation, and the local structural strength of the helicopter decreased, but the whole structural strength of the helicopter was hardly affected. As a result of the impact of shock wave alone action, the whole and local structure of helicopter was caused the large deformation. As a result of the impact of the combined damage of fragments and shock wave, the helicopter structure was caused perforation, the local and whole deformation, and even the whole deformation degree increased. The deformation caused by the combination of fragments and shock wave was larger than the deformation caused by the add of fragments and shock wave. Compared with the shock wave alone action, the helicopter’s destructive effect by the combined action of fragments and shock wave incresed by13.87%～18.46%.