The Analysis Of Destructive Mode Of The Underground Headquarters

This paper aims to work out damage effectiveness on the underground headquarters in different models by applying LS-DYNA and building simplified models. The main contents of this paper are presented in the following part.I. the research on penetration from the top of entranceThis paper introduces warhead design, and selection of target materials, material models, calculation parameters, mesh generation and algorithm. This paper selects mock bombs 36.8cm in diameter, 240 cm in length, and 3 in CRH, which penetrates vertically at the speed of 600m/s, and calculates the maximum depth of the earth penetration bomb. Moreover, this paper calculates the minimum speed of the same bomb when it penetrates the target which is 150cm in thickness.The calculation result indicates that the 600m/s penetration bomb can reach the maximum depth of 480cm. The calculation also shows the relationship curve of the speeds and the acceleration speeds of the same type of bombs which penetrates underground shelter of various thicknesses from top. The penetration speed is 220m/s when the target is 150cm thick.II. The research on damage of explosion inside the tunnelThis paper takes a preparedness command center located in the depth of mountains as the model. The entrance explosion model is established based on the structure of the command center. Due to the length of the entrance tunnel, this paper simulates the damage of the personnel and equipment in the working area caused by various dosages and calculates the maximum distance between the explosion point and the working area. Furthermore, this paper also calculates the pressure duration curve from the 8 spots of different distances from the explosion point of the same dosage.The result indicates that a maximum dosage of 303kg is needed if an explosion at the entrance is to cause heavy casualties to personnel and paralysis to equipment in the working area when the command center is built in the depth of mountains. Second, by comparison of the pressure duration curves of different distances from the explosion spot under 230kg, the decreased degree and the decreased time of peak overpressure increased gradually. That because the energy attenuated during the shock wave propagation, resulting in the decrease speed of peak overpressure faster than the spreading distance.The research findings of this paper have military and practical significance in the further research on damage of the underground headquarters center and the protection design of the entrance.