Study On The Pressure Field Of The Spherical Shell Structure Under Blast Loading

In recent years, with the terrorist attacks rising, the anti-terrorism situation of the world becomes more and more serious. Terrorist attacks not only cause immeasurable losses to the world's economy and politics, but also to the security of people's life and property. Long-span spatial structure is often considered as a landmark of a regional even the nation. It has more far-reaching political and economic significance. Therefore, the long-span spatial structure is more likely to become the targets of terrorist attackers. Consequently, the study on the performance of the long-span spatial structures under blast loading and resistance ability to the explosion load should be conducted imminently.This paper focuses on the pressure distribution of the spherical shell structure under blast loading. The well-known dynamic explicit finite element software LS-DYNA is used as a research tool to tackle this subject, and the whole process simulation of explosions is achieved. So the problems which are difficult to study in the model test are easily to solve. Through the comparison of the numerical simulation and analysis of explosion in semi-free air has been done, and a good agreement is achieved. That proves the LS-DYNA software can be used to calculate the category problem of long distance explosion.The rule of the pressure distribution on the structure surface and the methods of researching in a 40m spherical shell structure under the explosion in center are introduced in detail. And a method of extracting the pressure field distribution on the surface of the structure was proposed. By studying the rule of the pressure distribution, the influence of pressure field distribution with different parameters can be achieved. Different location of the explosives and the case that the explosive inside or outside the shell structure were analyzed respectively, and the influence of explosive detonation point on the pressure field distribution can be gained.In order to apply the blast load of spherical structure to the design of engineering, a simplified method of blast load of spherical structure was proposed. And the complicated explosion problem becomes simple by using the load partition and load curve which are all simplified. Through the analysis of the explosives locating at different height in the center of the structure, a number of mathematical expression of these parameters were formed, and then the engineering design of blast loading could become much easier.