Comparative Study on Structural Performance of Box-Type Hollow Roof and Traditional Roof

In this paper, a new type of spatial structure-aluminum honeycomb plate box-type hollow roof structure is proposed. It is a pentahedral or hexahedral box-type hollow roof structure composed of lightweight and high strength aluminum honeycomb plates spliced by special connectors. It not only has the characteristics of tension structure of light weight and high strength, but also absorbs the advantages of high strength and high stiffness of rigid structure. In order to explore the advantages of the structural performance of the box-type hollow roof compared with the traditional roof, based on the bearing capacity test of the aluminum alloy honeycomb plate box-type hollow roof, the mechanical properties of the box-type hollow roof were studied. Two finite element analysis models, the complete coordination model and the coupling model, were established by ANSYS software, and the effectiveness of the finite element analysis model was verified. The mechanical properties of three-dimensional grid single-layer reticulated shell, orthogonal pyramid double-layer reticulated shell, pentahedral box type hollow roof without bottom plate and hexahedral box-type hollow roof with bottom plate were analyzed, and its economy was analyzed. The results show that the aluminum alloy honeycomb plate box-type hollow roof has good connection performance and high spatial overall stiffness. The ultimate bearing capacity is as high as 11 times of the self-weight of the structure, and the stable bearing capacity is about 3.6 times of the self-weight. The deformation of the structure during buckling is minimal, and the deflection-span ratio is only 1/800. The coupled model is suitable for the finite element analysis of box-type hollow roof structure. It is consistent with the test in the elastic stage, and its ultimate bearing capacity is only 15% higher than the test value. It can be used as the design value of structural bearing capacity after considering the safety factor. In terms of static performance of reticulated shell structure, the mid-span deflection value and component stress ratio of box-type hollow roof structure with bottom plate are the smallest among the four, showing high bearing capacity and deformation resistance. In the case of similar mid-span deflection values, the component stress ratio of latticed shell with bar system structure is generally greater than that of plate system structure, and the spatial force transmission of plate system structure is more reasonable. In terms of the economy of the reticulated shell structure, for the same size of the reticulated shell, the box-type hollow reticulated shell without bottom plate has the smallest structural weight, while the three-dimensional grid type single layer reticulated shell has the largest building space. With the increase of the shell plane size, the average weight of the structure decreases, and the difference in the building space is also increasing. On the premise of satisfying the mechanical performance of the structure, considering the building space and structural weight, the box-type hollow structure can obtain relatively good economy. In terms of the dynamic performance of reticulated shell structure, the frequency of plate structure is generally higher than that of bar structure under the same conditions. The plate structure has the characteristics of light weight and high strength, and its mass and stiffness distribution are more reasonable than that of bar structure. The mechanical properties and economic indexes of box-type hollow roof are excellent, but they have their own applicable span range. The box-type hollow structure without bottom plate is suitable for reticulated shells with span less than 20 m, and the box-type hollow structure with bottom plate is suitable for reticulated shells with span of 20-30 m because of its greater stiffness.