Cast-steel joints characterized in strong adaptability are widely applied in various long span spatial structures. At present, there is no national design specification available on cast-steel joints. Therefore, it is quite a necessity to conduct full-scale test or model test on cast-steel joints suffering complicated forces. This Paper has, taking Nantong Sports Exhibition Center as an example, conducted the experimental study of some important joints, and compared with elastic-plastic nonlinear finite element analysis result. According to the result, the fracture morphology of joints, stress distribution and bearing capacity of joints obtained from the elastic-plastic nonlinear finite element analysis are consistent with those of measured result, proving that the analysis theory applied in engineering design is basically suitable for the actual working condition of cast-steel joints and the joints are sufficiently safe.

Position deviation of joints is a primary initial geometrical imperfection that affects the stability of long-span spatial structures. It makes field measurement of joint coordinate for the shell and roof initial shape of Nantong Sports Exhibition Center upon its completion. This paper researches the stochastic distribution feature and statistical parameter of geometrical imperfections for the data sources of above position deviation of joints by “abnormal data test method”. The results indicate that the distribution of abnormal data is concentrated, which is related to the difficulty of construction and condition of measurement; the distribution of joint position deviation can be assumed by normal distribution, and its mean μ=0 and mean square deviation σ=R/2 of statistical parameter are tenable. Meanwhile, It also puts forward a stochastic imperfection method based on measured imperfections and ANSYS－PDS platform, establishes a measured model to make nonlinear stability analysis, and respectively compares this critical load with that obtained by the perfect structure of ideal shape and the consistent imperfection method, so as to evaluate the stability and reliability of practical project in an objective manner, and provide reference for project design.

A convenient and reliable connection between panels and beams was investigated for collaborative work of single-layer composite reticulated shell structure in which aluminum alloy honeycomb panels participate. In the paper, the "self-tapping bolt" connection was adopted to realize the "tight fit" performance of connection effectively in the composite structure. Through three groups of bearing capacity test on 1.5 m×3 m square meters of the aluminum alloy honeycomb panel-square tube beam combined structure, the force characteristics and failure mechanism of the structures were studied. The experimental results revealed that the connection method could ensure effective transmission between the panel and the beam which made them work in excellent condition. In order to simulate complex performance connection with the panel-beam composite structure, tangential and normal contact behavior were considered at the bolt connection point between the honeycomb panel and the beam in ABAQUS analysis. The analysis results illustrated that the finite element results had the highest matching degree with the experimental values when the friction coefficient of the joint boundary was 0.25. The finite element analysis of the connection bolts spacing indicated that the economic and excellent connection effect can be achieved when the spacing was about 90 mm.