Study Of Integral Stability Coefficient For Homemade Rolled H-section Steel Beam

The simplified formula on torsion moment of inertia has some influence tothe homemade hot rolled H-section steel beam integral stability computation. Theresult indicates, this simplification bringing the error is orderly: generally, theformula gives smaller error values for small size sections and just the reverse istrue for large size sections. For HW section integral stability coefficient smallererror value section, belongs to the particular case, which is both of the flange edgeand web plate in equal thickness. This also conforms to hypothesis about theflange edge and web plate in equal thickness. For HN sections whose heighthigher than 600 millimeters (under the large length beam), the most sectioncalculation error is above 10％. The HT type is the newly increased section ofcountry standard GB/Tl1263-2005. Its small sections, especially flange edgeswith width less than 100 millimeters, have bigger error, the smaller the width is,the bigger error occur.The integral stability coefficient formula in criterion, is applicable for themost of homemade rolled H-section steel beam. The difference of thickness is 2-3millimeters between flange edge and web plate (including the same thickness offlange edge and web plate), the integral stability coefficient error is smaller, in theregion of 0.01. Other bigger section that flange edge differs with the web platethickness as well as arc radius, the integral stability coefficient error is bigger.Moreover the most of beam lose stability during the elastic-plastic range, theabove section of error by elastic-plastic correction have already drop greatly,therefore it is acceptable.Simplification formulary of stabilization coefficient in criterion is conservative excessively for homemade rolled H-section steel beam, based on theGB50017. But their error increases with the slenderness ratiOλ_y. For memberswith slenderness ratio larger than 85 ((235)／(f_y))^1／2, these formularies are tooconservative. This paper offers a relative simplified formulary for 120 (235／(f_y))^1／2Which is a little more complex but .much more accurate. It takes advantageousfactors into consideration while curly rectangle action happens, also it provides alist of critical length ratio for engineering design reference.