Dynamic Response And Explosion-proof Method For Two-point Asynchronous Internal Explosion Single-layer Spherical Reticulated Shell

The research on large-span space structure under the action of multi-point blasting load mainly focuses on synchronous explosion presently,but explosion case does not have synchronous explosion in the strict sense.According to the research progress of our department,this paper will focus on the situation under the two-point asynchronous explosion of the spherical reticulated shell.With the benefit of LS-DYNA finite element software that establishes a numerical calculation model of single-layer spherical reticulated shell structure,the space-time state of single-layer spherical reticulated shell structure was firstly determined,and then studied the shock wave propagation characteristics and overpressure of spherical shells under two-point asynchronous internal explosion.And the distribution and dynamic response are studied,and the theoretical basis for the explosion-proof and anti-explosion of large-span steel structures is provided at last.It mainly includes the following aspects:(1)Six working conditions were selected to study the placement of the two explosion points.The angles of the two explosives were 30 degrees,60 degrees,90 degrees,120 degrees,150 degrees and 180 degrees.The law of propagation,comparing the overpressure of the surface of the reticulated shell and the displacement of the apex of the reticulated shell under various working conditions,determined the placement position of the two explosives,in addition,three methods were used to determine the interval time between the two explosion points between0.01 s and 0.09 s.(2)The propagation law of the two-point asynchronous internal explosion shock wave of a single-layer spherical reticulated shell is studied.It is found that a large and small shock wave will be formed inside the spherical reticulated shell structure,and then the two columns of shock waves will meet,and the positions and locations where the two shock waves first meet each other the energy intensity varies with the explosion interval of the two explosion points.The overpressure curves of the reference points of the spherical reticulated shell structure are extracted and theoverpressure distribution is summarized.The influence of different parameters on shock wave overpressure under two point asynchronous internal explosion is analyzed.(3)By analyzing the dynamic response of the spherical reticulated shell structure under two-point asynchronous internal explosion,the dynamic response characteristics of the spherical reticulated shell structure under two-point asynchronous internal explosion are obtained,and the stiffness of the connecting member,the stiffness of the roof slab,and TNT are analyzed.The effect of the amount of drug,the spacing of the frying point and the height of the frying point on the dynamic response of the reticulated shell structure.(4)Finally,the complexity and difficulty of explosion-proof of single-layer spherical surface under two-point asynchronous internal explosion are expounded.On the basis of the fourth chapter,the explosion-proof method related to spherical reticulated shell structure is proposed.