Analysis On The Stability Of Honeycomb Beam In Pure Bending State

Castellated beams as a structural member (web perforation beams)have the advantages of light weight, bending stiffness, high capacity, aesthetic, economic and so on. Castellated beams are steel beams with a certain line on the web by cutting, and through assembling and dislocation welding, which have holes on the web. In this way, castellated beams increase the stiffness and bearing capacity by increasing the cross-sectional height, in which way we can achieve the purpose of saving the steel, improve the effective utilization of steel, reduce project cost purposes. According web perforation of different shapes, the castellated beam can be divided into a circular hole, oval holes, rectangular holes, hexagonal holes, octagonal hole in the form of castellated beams. Castellated beams in the form of diversification and so many advantages in practical engineering is widely applied.Stability is an important factor in steel capacity, steel stability mainly includes two aspects, In-plane bending buckling and out-plane bending buckling. In case of no lateral support member tends to produce out-plane bending buckling. Since the castellated beam web perforation, will cause some weakening web stiffness, therefore loads more prone to overall instability or local instability.In this paper, using the principle of balance method to derive formula of critical moment of castellated beams under pure bending case. Deduced simply supported beam and cantilever beam theoretical formula of critical moment. And apply the principle of equivalence to derived equivalent stiffness.In this paper, by ABAQUS finite element software modeling and analysis, analysis and calculation of different cross-sectional dimension, a different span, different hole size of the hexagonal hole, round hole castellated beams under pure bending at the critical moment, ABAQUS calculated value with the theoretical values calculated are compared, thus the critical moment of the castellated beam verify the correctness of the theoretical formula; Graphical analysis of the open hole size, hole shape, cross-height ratio and the constraints on the overall stability of castellated beams.ABAQUS calculated value of the castellated beam critical moment with ABAQUS calculated value of the solid web beam critical moment ratio as the critical moment castellated beams reduction factor. Regression analysis method to establish binary linear regression equation for curve fitting, combined with our design of steel structures (GB50017-2003) on the overall stability of solid web beam formula, raise the overall stability of the castellated beam formula, and for practical engineering castellated beam reduction factor of critical moment and overall stability of the formula.