The Elastic-Plastic Analysis Of Dynamic Resistant Capacity Of The Flat Double-Layer Shell

The shell structure is a net structure with curved surface, which has the inherent characteristic of both pole series structure and thin shell structure. Its major advantages are showed as follows: it has great span of covering and good whole rigidity, it is rational for the structure to receive strength and has good anti-seismic performance. It has made a lot of achievements in researching the structure properties and the shell stability of the shell under static strength. However, the study of dynamic response and anti-seism performance of the shell under the function of earthquake seems too less relatively, especially the study using the time-history to flat double-layer shell dynamic resistant capacity is too more less to be found, though the research of these kinds of shell above is very significant to the structure safety.In this article, the dynamic characteristic of the flat double-layer network shell structure has been analyzed with the iterative method of sub-space. The law that all kinds of influences on the structure frequency and the shaking types has been summarized also. In brief,the characteristic of shaking by itself of the structure is more sensitive to the area load, as the area load increasing, the basic frequency of the structure will decrease correspondingly, while the boundary condition has little influence on the characteristic of shaking by it self of the structure. The section size and the net shell thickness have much more complicated influence on it, there is an optimum component of section and thickness existed to make the basic frequency reach to the maximum.Meanwhile , the finite element procedure ANSYS9.0 has been carried on to analyze the dynamic resistant capacity of the flat double-layer shell working under strong earthquake by time-history analysis, and the law of the response of odal displacement and the stress of the pole and its parts to working under the function of the one-direction, two-direction, and three-direction earthquake has been analyzed contrastively. Some laws of the influence of flat double-layer shell on the earthquake wave's direction sensitivity have been discussed. Finally, through calculation and analysis , the influence of the ratio of the span and thickness on the dynamic resistant capacity of the flat double-layer shell structure has been summarized. In sum, flat double-layer shell structure's dynamic characteristic and its influencefactors ,and its dynamic resistant capacity have been probed into preliminarily in this paper,which is hoped to be beneficial to the structure design of this kind of shell.