Ivestigation On The Whole Stability Behavior Of Single-layer Triangular Reticulated Structure With Bolted Joints

With the advantages of lightweight structure,beautiful joints,high assembly rate,convenient construction and environmentally-friendly,the assembled single-layer spatial reticulated structure has become a hotspot in the research of large span spatial structure.The joints in assembled single-layer spatial reticulated structure can not be simplified as articulated or rigid connection.The actual mechanical properties of joints need to be considered.Therefore,the influence of the stiffness and bearing capacity of the assembled joints on the whole stability performance of the single-layer spatial reticulated structure is analyzed.Single-layer K8 reticulated shells with bolted joints are taken as research examples.Based on the mechanical properties of new bolted joints,which is the ring-sleeve joints and the double-ring joints,the numerical model of the assembled single-layer triangular spatial reticulated structure is established.The applicable span of two new types of bolted joints is studied,and the static stability behavior of two new types of assembled single-layer K8 reticulated shells under the maximum span is analyzed in detail,and the comparison with the rigid connection structure is made.The influence of rise to span ratio and span on the whole stability of assembled single-layer triangular reticulated structure is analyzed.The results show that the stability bearing capacity of the ring-sleeve joint single-layer K8 reticulated shell with the maximum applicable span is about 62%of the rigid structure,and the stability bearing capacity of the double-ring joint single-layer K8 reticulated shell under the maximum applicable span is about 58%of the rigid structure.Under design load,the maximum displacement and bar pressure of the assembled structure have little difference from the rigid structure,and the devation is less than 10%.With the increase of the ratio of rise to span,the stable bearing capacity of the assembled structure increases,and the stable bearing capacity of the assembled structure decreases with the increase of the span.The influence of the rotational stiffness and the ultimate bending moment of the bolted joints on the whole stability of the single-layer triangular reticulated structure is studied by numerical simulation.The results prove that the rotational stiffness of the bolted joints is reduced,the stability bearing capacity and the initial stiffness of the structure decrease,and the lowest eigenvalue buckling mode and the nonlinear instability mode of the structure gradually change from the whole instability to the local instability.With the increase of the ultimate bending moment of the bolted joint,the stability bearing capacity of the structure increases,but the degree of improvement is limited,and the nonlinear instability mode of the structure changes little.The stress distribution of the single-layer triangular reticulated structure is similar to the structural instability mode.The deeper the structure sag corresponds to the greater the stress of the bar.Finally,a new estimation formula for the stability bearing capacity of the single-layer triangular reticulated structure with new bolted joints is put forward.The above research findings are applied to the stability analysis of the assembled single-layer aluminum reticulated shell at Beijing new airport.The numerical simulation of the Temcor joints used in the assembled single-layer aluminum reticulated shell in Beijing new airport is carried out.The moment rotation curve of the joint is obtained,considering the Temcor joint stiffness single-layer aluminum reticulated shell numerical model is established.The influence of Temcor joint’s rotational stiffness on the static stability of single-layer aluminum reticulated shell is analyzed,amd it is compared with the static stability of the rigid structure.The results provide reference for the stability design of the assembled single-layer aluminum spatial reticulated structure and it has important engineering practice and theoretical research meaning.