Study On The Construction Control Theory And Temperature Effect Of Suspen-dome Structure

As an efficient pre-stressing spatial structure, the suspen-dome structure has been widely adopted in long-span buildings, such as gymnasiums, exhibition center and so on. Some burning problems have occurred during the researches and application of suspen-dome structures, which will make a significant effect on its cost and its safety. These problems include the design and numerical simulation theory of temporary falsework structures, numerical simulation theory of pre-stressing construction process considering the sliding friction and temperature change, numerical simulation theory of temperature field theory under solar radiation and its temperature effect and so on. Consequently, a systematical study was carried out to solve the above burning problems by theoretical analysis and experimental researches, and some achievements, having obviously scientific and technological significance, were obtained.The structural steel tube and coupler scaffolds (hereinafter referred to as STCS) were usually adopted as the mian falsework during the construction of suspen-dome structures. Many disastrous collapses of STCS's have occurred due to that no perfect design guidelines are obtained in current research. A systematic research on the structural characteristics, analysis method and design method have been conducted through experiments and finite element analysis and the numerical simulation theory and simplified calculation method of STCS were presented. In addition, the effects of various parameters on the stability of STCS were analyzed. Some achievements presented in this paper were adopted in the industry standard, technical code for safety of steel tubular scaffold with couplers in construction.A remarkable pre-stressing deviation is induced by the sliding friction between hoop cable and cable-strut joint, and this deviation brings hidden danger of suspen-dome structures. In order to research the pre-stress deviation distribution and its effect on the structural behavior, three numerical simulation method for the cable sliding were presented. The first method was presented based on heat expansion and cold contraction and generalized inverse, and this method can consider the sliding friction and can be realized in ANSYS software using APDL language. The second method was to derive the stiffness matrix of three-node cable sliding element based on the finite element theory, and this method can realized in ABAQUS software using its UEL function. The third method was also to derive the stiffness matrix of closed sliding polygonal cable element based on the finite element theory, and this method can realized in ABAQUS software using its UEL function. The above three methods were verified by example analysis and experiment. Using the above three methods, the distribution of pre-stressing deviation and its effect on the structural behavior of suspen-dome were studied as well as the structural behavior of suspen-dome structures with various friction coefficient. Based on those analyses, some meaningful conclusions were obtained in this paper.The temperature of suspen-dome structures and ambient air temperature are changing during construction, and the temperature changes bring technical problems for the pre-stressing construction. The pre-stressing deviation was investigated though example analysis and the analysis results showed that the deviation induced by temperature change during construction is up to 212%. So the temperature change must be considered in the pre-stressing construction. In order to consider the temperature change in pre-stressing construction, a new pre-stressing construction control method and simplified calculation formula, is presented in this paper, which is verified by example.The temperature load of suspen-dome structures is change during the construction and usage stages. Comparing with the common loads, such as gravity, wind load and seismic action, temperature action is quite different. The former loads can be overcome by increase the structural stiffness, but the temperature action cannot. Furthermore, the structural stiffness is lager, the stress and displacement is larger. The influence of temperature load on the pre-stressing value, node displacement, member stress and reaction were studied by finite element analysis.In the process of construction and service stage of suspen-dome, the temperature distribution is affected not only by ambient temperature but also by solar radiation. Considering the effect of solar radiation, the steel temperature may be 20℃higher than the corresponding ambient temperature. Therefore, there will be hidden danger under condition that a non-rational temperature distribution is used in design. In order to provide a rational temperature data for structural design, a numerical simulation model based on ASHRAE model is presented for the temperature field analysis considering the solar radiation, and a solar shadow algorithm was also presented in this paper. A parametric study was carried out in order to investigate the influence of the steel solar radiation absorption, the solar radiation reflectance, steel member size and orientation. Four groups specimens including steel plates, steel tube, steel rectangular tube and H-shaped steels were designed and measured not only to provide insights into temperature distribution of steel members under solar radiation but also to provide data to verify future analytical results and simplified design formula. Using above method, the temperature distribution and temperature effect of suspen-dome structures and suspen-dome with stacked arch were investigated, and some significant conclusions were obtained.