Integral Stability Analysis Of Honeycomb Beam Under Torsion

Castellated beam is a steel structure with holes in the web of I-section steel beam after a certain process. Castellated beam has the characteristics of steel saving, high bearing capacity and attracitve appearance, which has been widely used in practical engineering. However, due to the existence of eccentricity in practical engineering, castellated beam always supports the joint action of bending moment and tortion at the same time which makes the occurence of unstable failure before the strength failue.Domestic and foreign scholars on the research of the beam condition of bending and tor-sion are mostly based on plain girder. Though Specification For Design of Steel Structure (GB50017-2003)of China has given the overall stability calculation method of the simple beam of compound bending, there is no rule on the overall stability calculation of castellated beam under the joint action of bending moment and torsion. Meanwhile, though Cold-formed Thin-walled Steel Structure Technical Specifications (GB50018-2002) of China has given the overall stability calculation method of cold-formed steel beam under the joint action of bend-ing moment and torsion, it is not suitable for castellated beam. Thus, we are lack of a unified analysis and calculation method for the research on the overall stability of castellated beam under the joint action of bending moment and torsion, In conclusion, this paper has a certain scientific significance and application value for the study about the bearing capacity of the overall stability of I-section steel beam under the joint action of bending moment and tortion.By using of the method of energy, this paper has the theoretical analysis on the I-section steel beam under the joint action of bending moment and tortion. Then it reduces calculation formula of plain girder under the eccentric across the eccentric concentrated force and uni-formly distributed load with the combination of Cold-formed thin-walled steel specification (GB50018-2002) and Specification for design of steel structure (GB50017-2003). According to the principles about the simplification of moment of inertia and equal volume, this paper has given the calculation formula of beam under the eccentric across the eccentric concen-trated force and uniformly distributed load. In addition, on the basis of it, this paper has com-bined the finite element software ABAQUS to verify the accuracy of the formula. This paper has also calculated the critical moment of castellated beams and plain girder under the situa-tion of different eccentricity, different hole shapes, pore ratio and hole spacing. And according to the results of the calculation, this paper has given a bend torsion correction coefficientψ which concludes the formula solutionMcrand the finite element solutionM’cr under the ec-centric across the eccentric concentrated force and uniformly distributed load of castellated beam. Finally, with the use of the statistical analysis software Origin on the regression analy-sis, this paper has carried out the empirical formula of bend torsion correction coefficient ψ and it can be provided as the reference for the overall stability calculation of castellated beam under the joint action of bending moment and tortion according to the revised formula.