Static And Dynamic Stability Analysis Of The Large Span Suspend-dome

Suspend-dome is a new type of composite space structure system, which is composed of single-layer spherical reticulated shell and prestressed cables. In the past, the research of this kind of structure is limited to medium and small span. In the paper, static and dynamic stability characteristics of large-span suspend-dome structure are analyzed by means of the universal finite element software ANSYS.The contents of the research are as follows:1. The large-span suspend-dome structure static stability is analyzed, considering the cables layout the value of the prestressed cables, inner strut height, structure rise-span ratio, the initial defects of structure. It is found that the layout of the prestressed cables can improve bearing capacity of the suspend-dome, and the increase of rise-span ratios can obviously improve the structure stability; the cables near support play a critical role to the improvement of stability characteristic, and the increase of the initial defects significantly reduce stable bearing capacity.2. Vibration characteristics of the suspend-dome are researched. Various structure parameters including rise-span ratio, the initial defects, the weight of roof and supporting condition are considered in analysis.3. The dynamic stabilities of suspend-dome and single-layer spherical reticulated shell of 40m span under vertical, horizontal and three-dimensional seismic excitation is calculated respectively. It is found that the influence of the introduction of prestressed cables for structure dynamic stability mainly embody in the following respects:the introduction of the prestressed cables changes the force transmission path of the suspend-dome, improves the stiffness of the structure and ultimate bearing capacity and changes the deformation rule of the structure. And then the dynamic stabilities of suspend-dome of 40m and 120m span under vertical, horizontal and three-dimensional seismic excitation is calculated respectively. The differences in small-span and large-span suspend-dome embody in the following two respects:In order to control displacement, the large-span suspend-dome structure needs to exert greater prestress.When the acceleration amplitude is small, structural displacement is small. But when the acceleration amplitude once reaches bearing capacity, the structural displacement will suddenly increase. Compared with small-span structure, it reflects obvious property of brittle failure. The introduction of high intensity cables increase the stress of circumferential bars which connect to cables and make circumferential bars more easily reach plasticity.The research results of this dissertation are good references for actual project designing as well as a theoretical foundation to compile the relevant design criterion.