Research On Stability Of Single Layer Combination Of Aluminum Alloy Honeycomb Panel And Rod Latticed Shell

Because of its light weight, corrosion resistance and ease of processing, etc., aluminum alloy structure receives much concern in structural engineering and its use is increasing. Honeycomb panel that has advantages of higher specific stiffness, strength and good vibration isolation, insulation, impact resistance is a composite sandwich structure. This is the first study for the stability of a new aluminum alloy single-layer composite reticulated shell in combination with the high-strength lightweight aluminum alloy honeycomb panel. By analyzing a large number of examples, the results show that the stress behavior, buckling mode, failure mechanism and ultimate bearing capacity are very different from the monolayer aluminum alloy shell without plate. The main research contents and conclusions are as follows:(1) Through the finite element analysis of the solid model of connection between the aluminum alloy honeycomb panel and the rod, it is found that screw yield in the area of contact with the solid plate resulting in generating larger skew under extreme load, which declaring damage of the connection. There is no big difference between the results of the two models, and the difference of the ultimate load is with 7.4%. The equivalent plate instead of the honeycomb panel can be used to simplified analysis. The load-displacement curves of the connector model of different thickness of honeycomb panel has basically the same shape and failure mode.(2) Through static analysis of a new aluminum alloy composite reticulated shells, it is found that compared with monolayer aluminum alloy shells without plate with the same span, the maximum stress of rod is reduced by 45.3% and the maximum vertical displacement of nodes is decreased 81.3%. Economic analysis shows reticulated shells save material by 70.7% only for aluminum alloy rod, and by 16% on total cost. Therefore, economic performance of composite reticulated shells is excellent. In order to consider the connection between the honeycomb panels and aluminum alloy rods are not fully coordinated, the equivalent thickness of honeycomb panel can be reduced by 14%.(3) Eigenvalue buckling analysis on new aluminum alloy composite reticulated shells, it is found that buckling coefficient of composite reticulated shells is no less than monolayer shells without plate when the mesh size is larger. But with the reduced size of the mesh, buckling coefficient of composite reticulated shells is significantly greater than monolayer shells without plate, and even is almost several times than the latter. Parametric analysis on composite reticulated shells, the results show that the ultimate bearing capacity factor of composite reticulated shells under the initial geometrical defects of L/150 is only reduced by 19.6% compared defect-free perfect structure. Therefore, it is recommended to relaxing the controlling indicators of the initial geometry defect from the current standard L/300 to L/200. The ultimate bearing capacity is increasing with the increase of span ratio, which is different from monolayer shells without plate.(4) Adjusting sectional dimension of rod near the holder and thickness of honeycomb panel and eigenvalue buckling analysis on composite reticulated shells, it is found that when the cross-section of rod is constant, increasing the thickness can significantly improve characteristic values with an increase of 3 to 6 times. It is shown the stiffness of honeycomb panel near the bearing has a great influence on the stability of composite reticulated shells.(5) With the change of the mesh density and loading way, the buckling failure mode of the new aluminum alloy composite reticulated shell is transformed from local buckling of honeycomb panels to the overall instability of the structure. Geometric nonlinear analysis of defects stability on composite reticulated shells and monolayer shells without plate, the ultimate carrying capacity of composite reticulated shells that is 73.8% of results of the eigenvalue buckling analysis is 3.52 times than monolayer shells without plate, and the ultimate displacement is only 38.5% of monolayer shells without plate. It can be seen that geometric nonlinearity has a great impact on the overall stability of the new aluminum alloy composite reticulated shells. Analysis of double nonlinear defects stability, it is found that the ultimate bearing capacity factor is only declined by 11.2% compared with the results of geometric nonlinear analysis. The results show the impact of material nonlinearity of aluminum alloy on the overall stability of the new aluminum alloy composite reticulated shells is small, and it can be ignored.