Studies On Dynamic Stability Of Suspendome Structure

As a new type of spatial structural form, and by using the concept of Tensegrity structure, the suspendome structure integrates the single layer reticulated shell structure and the cable-dome structure. It is a new structure with vital energies which combines both benefits of the single layer shell and cable dome and can cover greater space properly and economically. Taking suspendomes with span of 50m as examples and by utilizing the software ANSYS, dynamic stability behavior of some proto-type suspendomes under severe earthquake is discussed. The main contents in this paper are as follows:1. Analysis on the free-vibration behavior is performed firstly, and a comparison between suspendome and the corresponding single layer shell is executed. Parametric analysis on free-vibration behavior is proceeded. The parameters in considering are: boundary conditions, rise-to-span ratios, prestress value of the cables, the number of the cable rings, structural loads. Some regular conclusions are drawn.2. Comparative analysis on dynamic stability of suspendome structure under single-dimensional and multi-dimensional earthquake excitations is carried out. The characteristic of dynamic stability of suspendome under multi-dimensional earthquake is generalized. The results indicate that there are marked diversities in response of the structure under single-dimensional and multi-dimensional earthquakes. And the responses are not entirely symmetrical. As the cable-bar system strengthen the structural rigidity, when the structure fail to work there is no remarkable sag in areas with cable-bar system. The sags which result in unstability often occur in the areas without cable-bar system and the top of suspendome.3. Dynamic instability and strength failure, two damage patterns of the structure under severe earthquake which determined by rise-to-span ratios are discussed tentatively.4. A comprehensive numerical study on dynamic stability behavior of some proto-type suspendomes is carried out with the following primary parameters: single-dimensional and multi-dimensional earthquakes, three different boundary conditions, various geometric and structural parameters , such as rise-to-span ratios , prestress value of the cables and the number of the cable rings, member cross-sections and various earth quake records.Some valuable conclusions are achieved for practical design and further study on the suspendome in this paper.