Research On Response Modes And Mechanism Of Single-layer Reticulated Spherical Shell Under Internal Explosion

Spherical shell, a kind of familiar large space structure form, has been widely usedin public buildings such as gymnasiums, theatres, museums and so on. It has becomea significant symbol of city modernization development. This kind of building iseasy to be a target of terrorist bombing on account of its crowd and active. Theresearch on terrorist explosion proof technology of large space structure cansignificantly enhance the antiknock ability of large space structure, reduce the loss ofhuman and property, remove the bad influence in society, maintain social stabilityand national security. Therefore, it has important theoretical and practicalsignificance to research on the response mode and mechanism of large spacestructure under internal explosion load.According to Schweitzer’s single-layer reticulated spherical shell as the researchobject, through the finite element numerical simulation, the response modes andmechanism under the internal explosive load are studied, the main contents are:(1) Using ANSYS/LS-DYNA finite element software to simulate the explosion ininfinite free air domain. numerical simulation results of peak overpressure andpositive pressure time were compared with experience formula calculation results toprove the credibility of the free air explosive numerical model, provide the basis fornumerical model of spherical shell under internal explosion.(2) Combined with the free air explosive finite element model, the whole processof explosion in the spherical shell structure is simulated. The numerical simulationresults is compared with empirical formula, shock wave propagation and reflectiontheory to verify the credibility of the numerical model of spherical shell underinternal explosion, determine the benchmark model of spherical shell under internalexplosion.(3) Numerical simulation of spherical shell under internal explosion is carried outby changing the connection mode and the connection stiffness to simulate theinfluence of structural response mode by different connections. On this basis, studying the effects on the structure response mode by changing the TNTequivalence of dynamite and spherical shell structure rise-span ratio.(4) The displacement time history curve, bar plastic development degree, energyrelations and other mechanical behavior are analysised to research the mechanism ofdifferent response modes.