Research On Damage Effect Of Frame Building Under Explosion Load

In modern war,the urban military buildings with defense and command functions are the key target of attack,and the blasting warhead which mainly relies on the blast wave to damage the target is an effective means to destroy the building target,so the damage effect and evaluation of the building under the explosion load is an important subject in the military field.In this paper,the damage effect of typical four-story and three-span frame buildings under explosion load is studied from the aspects of explosion damage effect analysis,building target characteristics analysis,reinforced concrete component explosion damage characteristics and building structure damage index assessment under explosion.The relevant research results provide reference value for the rapid assessment of building damage degree under explosion load.In order to study the effect of cylindrical charge equivalent and its position relationship with member on the damage degree of reinforced concrete member,the damage effect of member under different working conditions was simulated numerically for four kinds of charge equivalent of MK80 series general purpose blasting warhead.The results show that the damage degree of component increases with the increase of equivalent,and the column charging axis is kept parallel to the supporting column.When the Angle between the minimum line segment from the column charging point to the axis of the supporting column and the 1/2 section of the supporting column is in the range of 20°-30°,the damage degree of the supporting column is the largest,and the wide surface of the supporting beam is the blast facing surface.Based on the damage weight and damage degree of components,an evaluation method of the overall damage index of buildings was established to quantitatively represent the damage degree of buildings.On this basis,the influence of the equivalent of cylindrical charge and its spatial location on the damage degree of buildings under explosion load was studied by numerical simulation.The research shows that for internal explosion,the overall damage degree of the building at different heights is from large to small in the top of the first floor of the building,the middle of the first floor,the bottom of the second floor and the middle of the second floor.The overall damage degree of the building at different horizontal positions is from large to small in the middle of the building,the corner of the building and the middle of the side.For external contact explosion,the damage degree of the building at different positions from large to small is the external side wall,the external middle wall,the external middle column,the external side column.The damage degree of the building under the blast load is compared and analyzed,and the damage law of the building under different working conditions is obtained.The results show that the detonation position of cylindrical charge has a great influence on the damage degree of the building.Compared with the detonation of 505.04 kg charge in the middle wall outside the building,the damage index of the building increases by 77.51 when 238.36 kg charge is detonated in the middle of the top of the first floor inside the building.In general,the damage degree of the building when the charge is detonated inside is greater than that of the outside,and the damage degree of the building when the charge is detonated at low level is greater than that of the high level.When the cylindrical charge detonates in the middle of the top of the first floor inside the building,the damage to the building is greatest.