Behavior Analysis And System Improvement Of Cable Domes

The cable dome is one kind of spatial structures and its rigidity is offered by prestress. Though it comes from the tensegrity concept proposed by Fuller, strictly speaking, it is not a kind of tensegrity structure. The main difference lies in its boundary compression ring, which is something inconsistent with the self-support definition of tensegrity system. The earliest application of the cable dome is the Korea Olympic Game gymnastics building and fencing building in Seoul in 1988. Henceforth the new style is widely known as its lightness and excellent performance all over the world.The development of spatial structures is first introduced briefly, especially the development of flexible system such as tensegrity structure, and then the main research contents of the thesis are presented.Cable dome is composed from cables and struts, and belongs to the cable-strut structures. So some foundation analysis methods of the cable-strut can be applied to this kind of structure, such as form finding, geometric stability analysis, determination of prestress and load performance analysis etc. Being a special kind of cable-strut structure, some simple methods for prestress-determination and geometric stability analysis are presented according to the concept of overall feasible prestress for its symmetric geometry.Nonlinear finite element method must be used for the load performance analysis of the cable dome for its highly geometrical nonlinearity. In this thesis the performance of the ribbed cable dome under the whole-span and half-span load condition is analyzed by using universal software of finite element method Ansys. The effect of different parameters on the limit bearing capacity is also investigated by parameter analysis.Considering the importance of deficiency sensitivity analysis of cable dome, three kinds of deficiency including geometric error of supports,length errors of cables and rigidity error of supports during the process of manufacture andconstruction are considered and the influence on the static behavior of the structure is studied. As the randomicity of errors and its dimension, probability statistics is applied to simulate the geometric errors of supports and the length errors of cables, and flexible supports with different rigidity is adopted to consider the supports' rigidity.Ribbed cable domes have advantage in easy design and construction due to ribbed arrangement of radial cables. However ribbed cables system leads to the low out-plane stiffness of the structure and the inner cables often relax under external load. In order to improve the behavior of ribbed cable domes, two modified system is proposed. One is to replace inner cables by stiffness cables and the other is to arrange constructional cables. The load performance, dynamic modal and earthquake reaction of two modified structures are analyzed detailedly. The numerical results show that the modified ribbed cable domes have better static and dynamic performance than the normal ribbed domes.At the end of the thesis some basic conclusions are summarized and the research may be studied is put forward.