Research On Damage Assessment Method Of Coupling Effect Of Shock Wave And Fragment Under Internal Blast In A Cabin

Semi-piercing anti-ship missiles are the main threat weapons for large naval ships.When a semi-piercing anti-ship missile warhead exploded in the cabin,the explosion shock wave and the high-speed fragment group were important damage loads.The explosion shock wave-fragment coupling damage in the cabin had a special mechanism of action.In this thesis,the damage assessment method of explosion shock wave-fragment coupling damage in cabin was studied by using the method of empirical calculation,numerical simulation and experiment.The research work and conclusions of this paper are as follows:Based on the characteristics of the shock wave and fragment load in the air,combined with the relationship between the velocity and distance of the wave-front and the equation of motion of the fragment in the air,the critical distance calculation of the shock wave and fragments based on the anti-ship missile warhead was given.The method reveals the damage mechanism under the action of shock wave-fragment coupling and obtains the theoretical calculation of the critical explosive distances for the four typical warheads.Through the designed cabin model,the principle experiment of exploring the damage mode of the internal blast wave in the cabin was carried out for the four types of the lid structure.The difference between the air blast damage and the internal blast wave damage of the lid structure was analyzed,and the influence of the connection mode on the internal blast performance was clarified,provided reference for the subsequent numerical simulation and experiment development.Experiments based on the cabin model of the internal blast shock wave-fragment coupling damage were carried out.The non-preformed-hole plate,the offset preformed-hole plate and the uniform preformed-hole plate were used to experimentally simulate the shock wave-fragment coupling damage effect of the fragment first arrival.A series of experiments on three kinds of target plates were conducted using two kinds of blast distances.The experimental results show that the shock wave-fragment coupling damage is more effective than the shock wave damage alone;the failure modes of the preformed-hole plate are close to the tearing of the petals and the critical tensile tear;the explosion shock wave inside the cabin will generate reflections and convergence,flat wall surface,two-wall surface and three-wall surface reflect peak overpressure first peak was different,the first peak and blast distance is not directly related,the long-distance shock convergence peak overpressure is still high.In the case of equal stand-off distance,the gain of the target plate deflection deformation due to weakening of the target plate is greater than that of the blow-out of the preformed hole.In the case of unequal stand-off distance,the target plate has a remote damage amplification effect.The experiment was verified by numerical simulation method,the simulation results and experimental results show good consistency.