Study On Capacity And Effects Of Composite Blast Resistant Wall

In the explosion accident,the blast resistant wall structure can effectively reduce the explosion damage caused by shock wave and fragments on people and buildings.Nowadays due to the complexity and risk of the production process,blast resistant wall demands higher capacity.The development trend of blast resistant wall is composite structure made of explosion-proof plate and steel frame.This form of structure is lightweight,and has high strength and high energy absorption capacity.It can be used as temporary or long-term explosion protection structure.In this article,a new composite blast resistant wall which is composed of sandwich panel and square steel frame were analyzed.The deformation mode of the structure is complex when subjected to blast loads,and hasn't been studied clearly yet.In order to reveal the deformation mechanism of the structure,and to provide theoretical basis for the engineering design,experiment and numerical simulation method were utilized to analyze the dynamic response of structure under explosive loads and the influence parameters that affect the resistant capacity.(1)The experimental study on blast resistant capacity of the structure.Experiments were designed to explore the deformation mechanism of structure when subjected to various blast loads.Experimental results represented that when subjected to explosive loads lower than 661.4 kPa,the maximum deformation of plate arose at center of the plate.And the shear deformation at the boundary of the plate became obvious when the blast load getting greater than 661.4 kPa.Plus,the composite blast resistant wall showed significant protection capacity when subjected to explosive loads generated by close and huge explosive charge.(2)The numerical simulation of the plate under blast loads.The effects of explosive charge and detonation distance on the dynamic response and deformation modes of the structure were studied.When the explosive load was less than 685.7 kPa,the main deformation mode of the plate was tensile and bending deformation at the center.When the blast load was more than 685.7 kPa,but less than 2445.8 kPa,the deformation mode of the blasting plate was mainly shear deformation along the clamped boundary.When the blast load is more than 2445.8 kPa,local penetration was caused at the central position of the plate.(3)By altering the thickness of the outer layer — steel shell and the core layer — concrete plate,the structural parameters of the plate were optimized.According to the parameter optimization analysis,0.75 mm is the critical thickness of steel shell,while 10 mm is the critical thickness of concrete plate.(4)By altering the spacing between the frame and section parameters of the square steel,the structural parameters of the frame were optimized.Square frame can effectively reduce the stress concentration of the plate at the midpoint of boundary.The square tube section parameters have a little effect on the deformation process of the plate.It mainly affects the strength of the frame and the deformation of the frame part,thus affecting the overall displacement of the structure.Through all research above,the dynamic response process of the composite blast resistant wall under blast loads were revealed.The influence law of explosive charge and detonation distance on damage mechanisms of blasting plate were obtained.The parameters optimization analysis of the composite blast resistant wall can provide the basis for the engineering design.