Research On Mechanical Properities Of H-beam With Web Opening

Steel beams with web openings have great significance in both structural design and comprehensive economic benefits because they can effectively reduce the building height due to allowing a large number of equipment pipes to pass through.The stress of steel beams with circle web opening is more reasonable and the shape is more beautiful.Therefore,it has a good application prospect in industrial and civil buildings.At present,there are some achievements on this kind of component in our country,but the research results are far behind the engineering practice.Although the current Code for Design of Steel Structures GB50017-2017 adds the content of beam with web openings to the "Flexural Members(Chapter 6)",but the content is only about constructive measure or conceptual design and does not give an explicit design calculation formula,which significantly hinders the wide application of beams with web openings in China.Therefore,further study is required.The following work has been carried out for the mechanical properties of steel beams with web openings:Firstly,this paper systematically expounds the engineering application and research results of steel beams with web opening in the past 30 years at home and abroad,summarizes the shortcomings in the current research and points out the direction of this study.Secondly,By domestic H-beam type and the common opening ratio,the calculation model of a supported cantilever beam with web opening is established by finite element analysis software ABAQUS.By adjusting the length of the cantilever steel beam and the displacement of beam end,the analysis data of the perforated section under different Bending-shearing combinations are obtained.On this basis,a simplified formula for calculating the pure shear resistance of the opening section is proposed.After fitting,the design equation of the correlation between bending and shear capacity of the perforated section can be obtained.The applicability of the bending-shear correlation equation is verified by the non-linear analysis of steel beam with web opening under concentrated load.Thirdly,According to the vierendeel truss method,this paper presents a theoretical formula for calculating the deflection of steel beams with web openings;and verifies the correctness of the formula.By studying the influence of opening ratio,span-height ratio and load type on a deflection,a simpler and more efficient method for calculating deflection of beams with openings is proposed.For steel beams with regular openings,this paper also studies the overall stability of the beams under pure bending loads,analyses and calculates the influence of the openings ratio,distance-height ratio and span-height ratio on the critical bending moment.Based on the theoretical deduction and finite element analysis data,the formula for calculating the overall stability and the reduction coefficient of critical bending moment of the castellated beams suitable for practical engineering are proposed.