Research On The Calculation Method Of Rectangular Hole Castellated Beam Structure

Castellated beam is a new steel component. Because of being made openings in the web, castellated beam can save material and reduce the weight of structure. In addition, it provides convenience for the layout of pipes and other equipment, and it makes full use of the architectural space. So, castellated beams have been widely used in large.span structures, high-rise buildings and so on. However, due to the influence of holes, the mechanical properties of castellated beam are changed. Therefore, the study of castellated beam is necessary. In this paper, rectangular hole castellated beam is studied in detail by three methods, which include theoretical analysis, numerical calculation and experimental analysis.First of all, the stress distribution of rectangular hole castellated beam is studied by using the finite element software, including the stress distribution of pier and beam bridge. In addition, the stress on the center of pier cross section is analyzed in detail, which is influenced by span-depth ratio, width-depth ratio, length-depth ratio and space-depth ratio. Meanwhile, the calculation expression of stress distribution is proposed.Secondly, based on the knowledge of mechanics of materials and structural mechanics, castellated beam deflection formulas by using Altfillisch’s vierendeel truss method is revised, including bending deflection, shear deflection and shear bending moment deflection. Moreover, compared with the results by finite element method, correction formula has a higher accuracy.Then, the stress distribution and deflection of rectangular hole castellated beam are analyzed by the experimental method. This paper designs 10 kinds of experimental models and compares results with each other, including the stress of pier cross section and longitudinal section, the stress of beam bridge and deflections at different locations. At last, finite element method and correction formula are proved correct by comparison.Finally, rectangular hole castellated beam is applied to portal frame construction. The calculation methods of internal force and displacements in castellated beam portal frame construction are proposed. Internal force and displacements under horizontal loads and vertical loads are calculated. Compared with the results by finite element method, this method is proved applicable, and it can provide a reference for engineering design.