Research On The Second-Order Analysis Of Multi-Story Residential Frame Building In Light Steel Structure Under Wind Effect

The multi-story residential buildings in light steel have many advantages, such as, high-strength, environmental protection and quick construction speed. The most suitable define about this new structure system is that the building is built up by frame beam-column using light hot-rolled H,light welded H,square steel tube or circle steel tube, and retained and protected by light material. In the low intensity region, it usually use pure frame system whose span spacing is between 6m and 8m, and the spend of steel is between 40 kg/m2 and 50 kg/m2.In this thesis, the second-order effect of a multi-story residential building in light steel is analyzed and calculated with considering wind effect, and the accuracy level of second-order formula in Code for design of steel structures has been analyzed. In the chapter three, the second-order effect of the moment, share and axial force in frames of a single-span one-story rigid frame and a single-span three stories rigid frame have been analyzed. Then, the calculation results have been compared with ANSYS results. In the chapter four, the accuracy level of second-order formula in Code also have been analyzed. At the meanwhile, the second-order effect of building height change and wind pressure change have analyzed. At the end, the 3D model result considered the second-order effect have been compared with the result of 2D model.By comparing with FEA method results by ANSYS, it's confirmed that the second-order formula in Code for design of steel structures is accuracy in moment calculation and the error is between 0.6% and 2.3%. Totally, it also can be used in second-order effect calculation in share and axial force. By the calculation example in the chapter three and four, the numeric results of Code formula is large than ANSYS result. So the use of Code formula is safer. The further research indicates that the second-order effect in building height change is lager than in wind pressure change. The former moment increases is from 15% to 27.8% by floors change from four to eight. The moment increases around 15% by the wind pressure change from 0.3 kN/m2 to 0.5 kN/m2. So it must put more attention to second-order effect in the multi-story residential buildings in light steel. Finally for calculating the second-order moment, it's more accurate and faster to use 2D model in regular frame.