| The roof of the spatial structure system of steel empty web truss girder and hollow sandwich plate is made of hollow sandwich plate,and the steel hollow truss beam is used between columns.The intercolumn plate of the hollow sandwich plate is used as the upper and lower strings of the hollow truss beam.The hollow truss beam can be arranged evenly or interlaced.Compared with the ordinary hollow sandwich plate-column system,this kind of structure system has some advantages in mechanical performance when it is used to span large space.This kind of structural plates and beams are empty-stomach members,but not real-belly members,and their self-weight is much smaller than that of real-belly structures.In this paper,the structural characteristics and static and dynamic performance of the structure are studied.The static behavior of a two-story cross-story steel hollow web truss-hollow sandwich plate structure is analyzed by finite element method(FEM).The results show that all the upper ribs(or upper chords)of the steel empty web truss girder-hollow sandwich plate structure are mainly subjected to axial pressure and the lower ribs(or lower chord)are mainly subjected to axial tension.Under the loading,the deflection of the single span of the floor increases gradually from the supporting point of the column to the middle of the span,which is in the form of an "ellipsoidal bowl".Through parametric analysis,it is found that the ratio of span to height has the greatest influence on the deflection of the floor,which should be used as the main control factor to control the deflection of the floor,followed by the stiffness of the shear bond.In order to analyze the dynamic characteristics of steel empty web truss beam-hollow sandwich plate structure,the finite element subspace iteration method is used to analyze the low-order amplitude and frequency of the structure.The results show that the first 3 order are mainly translational and torsional,the latter 9 are mainly vertical vibration,the first 3 have the force characteristics of the frame structure,and the latter 9 have the stress characteristics of the plate in the low order vibration of the steel hollow web truss beam-hollow sandwich plate.The parameter analysis of the dynamic performance of this kind of structural system is carried out.The fundamental frequency of steel hollow web truss beam-hollow sandwich plate structure decreases with the increase of concrete thickness,with the increase of span-height ratio,and gradually increases with the increase of shear bond and column stiffness.It increases with the increase of the stiffness of the upper and lower ribs of the steel empty web truss beam and decreases with the increase of the ratio of length to width of the structure.The width of column section has the greatest influence on the fundamental frequency of the structure.Because of the poor lateral stiffness of the frame structure,the lateral stiffness of the steel hollow truss beam-hollow sandwich plate structure is analyzed,and the influence of the stiffness of each member on the lateral stiffness of the structure is studied.The analysis results show that the column stiffness of the structure is the most obvious to the lateral stiffness of the whole structure.In summary,the steel empty web truss beam-hollow sandwich slab floor structure has the advantages of light weight,high stiffness and good economy,among which the stiffness of column has the greatest influence on the static and dynamic performance of the whole structure.However,compared with the solid plate,the hollow sandwich plate is lighter,more reasonable in force and less in material.Compared with the frame structure,the lateral stiffness of the frame structure is larger. |
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