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The temperature effect often significantly affects the performance of large-span spatial structure and even becomes one of the controlling loads. To obtain the non-uniform temperature field distribution of the thin-walled steel members under solar radiation and the influence rules of various factors, in this paper, experimental studies are carried out with three groups of specimens including rectangular steel tube, I-shaped steel and circular steel tube. Based on the test data, the non-uniform temperature field distributions considering the influence of solar radiation intensity, member size and surface coating are analyzed in detail. Then, numerical methods for the temperature field of steel members are studied considering multiple environmental factors. The validity of the numerical method is evaluated with test results. Finally, based on the parametrical studies of the major influence factors, a simplified calculation approach is presented for practical engineering applications. The experimental study demonstrates that the non-uniform temperature distribution of steel members truly exists and cannot be overlooked. The numerical method for the temperature field in this paper is effective, and the simplified calculation approach can meet the required engineering precision. The research methods and conclusions of this work can provide valuable references for thermal design, monitoring and control of steel structures. [ABSTRACT FROM AUTHOR]

Most existing studies on single-layer spatial structures with semi-rigid joints were focused on spherical domes. The present paper analyzed the squared plan-form single-layer structures, examining the influence of joint-rigidity on the mechanical performances of the structures. An experiment has been conducted on a 5×6 m single-layer cylindrical reticulated shell with semi-rigid bolt-ball joints. The mechanical performance of the latticed shell is investigated in detail. Finite element analysis (FEA) model of the latticed shell is established taking material and geometric nonlinearities into account. The results show that the behavior determined using the FEA models correlates well with the experimentally observed behavior for the single-layer structures with semi-rigid joints. [ABSTRACT FROM AUTHOR]

Abstract: Socket joint systems are typical semi-rigid joints used in space structures. This paper presents numerical analyses of semi-rigid joint systems in which the bolts are pretensioned. Eleven numerical models of socket joints are studied: three of them are subjected to bending and the others are subjected to proportional bending and axial compression. Moment–rotation relationships of the joints are obtained using models in which the material and geometric nonlinearity are taken into account. The load-carrying mechanism of socket joint system is investigated in detail through the numerical analysis. Through comparison of the finite element analysis (FEA) and corresponding test measurements, it is shown that the proposed FEA models can be used effectively to describe the mechanical performance of the semi-rigid joints in spatial structures, including the initial bending stiffness, ultimate bending moment, deformation and the failure mode. [Copyright &y& Elsevier]

Abstract: A new classification system for the joints in lattice shells is proposed. The stiffness and moment capacity of the joints together with the overall structural behavior of the lattice shells are considered in order to establish the classification system. According to this new system, joints in lattice shells can be classified into unique categories: rigid, semi-rigid or pinned. The rigid joints have both high bending stiffness and moment capacity; the semi-rigid joints have both moderate bending stiffness and moment capacity, and the pinned joints have either low bending stiffness or low moment capacity. Determination coefficients α and β are defined, based on the stiffness and moment capacity of the joints, and these are used to establish clear boundaries between the different categories. Some numerical examples are included to demonstrate the validity of the classification system. With the help of the classification system, an efficient process for practical engineering design is proposed, which can help designers choose the appropriate analysis method for lattice shells with different joints. [Copyright &y& Elsevier]