Research On The Method Of Explosion Venting For Large Space Cylindrical Shell Steel Structure Under Internal Explosion

In recent years, terrorist bombings have occurred frequently at home andabroad. For the public buildings of large space structures, the antiknockresearch has theoretical and practical significance, but the research is still inits infancy in China. In this paper, the single-layer cylindrical reticulated shellstructure was chosen as the research object, numerical simulations werecarried out by ANSYS/LS-DYNA, through the analysis of free air explosiveparameters impact, the validation of the structure implosion and the layout ofbuilding envelope for the research of explosion venting of the structure, thecorresponding relief measures could be put forward. The main researchcontent and achievements include the following five parts:(1) Based on the summarize of the explosion shock wave empiricalformulas at home and abroad. A numerical model for simulating the TNTexplosion was established and the numerical calculation for air explosion wascarried out, through the comparative analysis of the numerical results with theempirical formulas and the explosion experimental data. The research resultsshowed that the early common empirical formulas and the numericalsimulation results that were respectively in the median-lower value and lowerlimit of the explosive shock waves overpressure, underestimate the danger ofexplosion shock wave.(2) The effect of material parameters of dynamite, TNT equivalent,meshing density, modeling ways, air domain shapes and shapes of explosiveon the explosive shock waves overpressure were calculated and analyzedbased on the model in this paper. Based on the above research, the calculationmethod of explosion shock wave was proposed, the result of numericalsimulation could be corrected. The research results showed that the effect ofthe various parameters on the numerical simulation results were in differentlevels. The revised calculation results could improve the accuracy of thenumerical simulation results. (3) Two models of one building envelope that was full of rigid and the otherwas elastic-plastic were selected to establish the numerical model of thesingle-layer cylindrical shell structure under internal explosion, through theanalysis of the experimental phenomena and the results of numericalsimulation, the credibility of the calculation model and the parameterselection was verified.(4) By analyzing the effect of building envelope failure strain, stiffness,opening form (including the ratio of holes, the number and the positionopenings) on structural dynamic response, the explosion venting effect andthe value of explosion venting valve could be put forward. The results showedthat the effect of failure strain was more obvious with the TNT equivalentincreasing; Reducing the stiffness of building envelope could weaken theresponse degree of the main structure; The explosion venting effect ofbuilding envelope was related to TNT equivalent closely; Different openingforms effected the explosion venting performance of the structure obviously;The value of explosion venting valve could be used to analyze the degree ofthe explosion venting of the structure qualitatively.(5) According to the effects of building envelope materials, stiffness,explosion venting forms (all area, amount and position) and the value ofexplosion venting valve on explosion venting properties, correspondingengineering explosion relief measures could be put forward, providing areference for the design of blast resistant.