Study On Structure Selection And Mechanical Properties Under Special Load Of Cable Domes

Since Geiger applied the concept of tensegrity to the gymnasium of Seoul Olympic Games in 1986,cable domes had been gradually developed as a new type of large-span space structure with high force efficiency,light weight and simple appearance.In recent years,many scholars at home and abroad have studied the form of cable domes and mechanical properties of cable domes,which make cable dome structures gradually used in large public architectures such as stadiums and gymnasiums.Based on Tianjin University of Technology Gymnasium,which is the first 100-meter-span hybrid cable dome structure in China,this paper conducted structure selection analyses,non-uniform snow load researches and temperature effect researches to further understand this new cable dome structure,as follows:Aiming at the form-finding of elliptical hybrid cable dome with unequal boundary height,this paper briefly summarized and described the common methods of formfinding at present,and demonstrated the limitations of the commonly used form-finding methods according to the special type of the cable dome in this paper.Finally,a stepby-step unbalanced force iteration method was adopted to complete the Levy cable dome structure.Then cable dome models were established.Thereafter,the static and dynamic performances of Levy cable dome and the hybrid cable dome were compared and analyzed emphatically.It was found that the hybrid cable dome was most suitable for this project.In this study,a 1:15 scale model of the roof structure was made and taken as a research object.Then a static load test was performed on the model,considering 1/8,1/4,and 1/2 regional distribution of snow load,the influences of different snow distribution forms on the mechanical properties of the hybrid cable dome structure were obtained.Several relatively adverse snow distribution forms were selected to conduct a whole load process analysis of the structure considering geo-metric nonlinearity.Results indicated that,under the action of snow load with half-span distribution along 45° axis and diagonal half-span distribution along long axis,much lower structural bearing capacity would be obtained.Accordingly,a parametric analysis was implemented considering the effect of initial prestress and cable cross section,and the influence laws of the two factors on the mechanical properties of the hybrid cable dome structure were acquired.In order to study the influence of temperature change on cable dome structure,the long-term temperature monitoring of cable dome structure model was carried out,and the error between measured and analyzed values were analyzed.Considering geometric nonlinearity,the influence of temperature on ultimate bearing capacity of structure was analyzed.It was found that the ultimate bearing capacity of structure could be improved to some extent by decreasing temperature appropriately,but the effect of continuous cooling on ultimate bearing capacity would become smaller.On this basis,a parametric analysis was implemented considering the effect of initial prestress and external load,and the influence laws of the two factors on the mechanical properties of the hybrid cable dome structure were acquired.Consequently,a theoretical basis was provided for the analysis and design of this new-type cable dome structure and its engineering application.