Structural Analysis And Experimental Study On Suspen-dome Structures With Sliding Cable-strut Joints

How to precisely apply the prestress into the suspen-dome is one key issue during the construction process, and stretching hoop cables is widely used in practical constructions. In order to reduce the friction loss, a new type joint named rolling cablestrut joint is proposed in previous research. To study the structural behavior of the suspen-dome with sliding cable-strut joints by experimental methodology and as well, to compare it with the performance of the upper single-layer reticulated shell, is of significance in evaluating the efficiency of the suspen-dome. Due to the geometry characteristics of the ellipsoidal suspen-dome, the application of stretching hoop cables in the ellipsoidal suspen-dome structures directly impacts the promotion of the suspendome structures. Though the sliding cable-strut joints can effectively reduce the friction, the friction still existed. How to accurately assess the entire behavior of the structures when considering the friction between the cable and the cable-strut joint is needed to be resolved during the research of suspen-dome. Besieds, the influence of prestress random error during the tension process on the structural behavior also need to be paid attention to. In this paper, mechanical performance of suspen-dome with sliding cablestrut joints is deeply studied.The most direct way to evaluate the effect of the sliding cable-strut joint on improving the structural behavior is to get the pretension force at both sides of cable joint and calculate the prestress loss. Therefore, a cable force determination method that based on the direct determination principle is proposed. This method is then tested and verified by experimental and theoretical analysis.A new equivalent friction element is proposed for solving the problem of friction loss. Furthermore, the structural analyzing method considering friction loss is established, and then verified by experimental test. By applying the equivalent friction element into the finite element study of cable-strut structures, the frictional prestress loss pattern and its influence to the whole structure is obtained.Both theoretical and experimental analysis for suspen-dome and its upper shell are conducted in the study. A simplified internal member force calculating method is put forward. A 1:10 scaled-down suspen-dome model for Chiping Stadium was set up and used for experimental testing. The internal force distribution of the single layer reticulated shell under full-span and half-span load was acquired before applying the pretension force, the result of which also verified the correctness of the proposed theoretical analysis. Then the pretension force was applied into the structure and static test for the suspen-dome structure was conducted. The results reflects the internal force flow behavior during the construction process and indicates the internal force distribution under different loading conditions.As for the ellipsoidal suspen-dome, cable force along the hoop is different in the same ring. The hoop cable stretching method is not adaptable. In this paper, initial balanced state of 3 general used ellipsoidal suspen-domes is analyzed to get the necessary condition for uniform cable force distribution in the same ring. For one cablestrut structure with uneven cable force, an extended force density method is adopted for a modified form finding process until a uniform cable force situation is reached.Random errors are inevitable in the prestressing construction, which has negative effects on structural performance. Based on statistics and probability theory, the sensitivity of mechanical performance to random errors are studied, and the effects of mechnnical performance extent to different structural behaviors are also discussed. Considering the mechanical importance of outermost ring cable, it is highly recommended that the construction and precision of the outermost ring cable should be strictly controlled.