DSM For The Moment Capacity Of Profiled Steel Sheets

Profiled steel sheeting is a special form of cold-formed thin wall steel. The plateswhich compose of the cross-section of profiled steel sheeting with a larger ratio of widthto thickness. And under the action of external load, the compression flange can easilyresult in local buckling. Due to the factors of membrane effect and so on, there ispost-buckling strength can be made use of when local buckling emerges. At present, wemainly use the effective width design method to consider the impact of local bucklingstrength on the carrying capacity of the member. The effective width method mustcalculate the corresponded effective width according to the stress distribution oncross-section firstly. And then calculate the effective section properties, however, thecalculation process is usually complicated.The main content of this paper is to solve this problem. Firstly, based on the directstrength method (be called DSM for short), the formula to calculate carrying capacity ofprofiled steel sheeting in pure bending was proposed. Then, made analysis of five kindof profiled steel sheetings by ANSYS finite element software. And caculated theflexural capacity of members in pure bending. A comparison of the flexural capacity hasbeen made by calculation results of ANSYS finite element analysis, current Chinese andforeign specifications, and the formula based on the DSM for profiled steel sheeting. Itis demonstrated that the formula based on DSM can be more accurately in calculatingthe flexural capacity of components. Meanwhlie, it avoids the trouble to calculate thecomplicated effective cross-sction properties. It’s very convenient to use.When using DSM for design, the key point is to calculate local buckling criticalstressf olof the cross-section. Based on large amount of calculations, this paper analyzedthe impact of the ratio of the web width to the compression flange width named h b andthe ratio of the width of tensed flange to the width of compressed flange named d b onthe coefficient k of local buckling. A simplified formula to calculate the local buckling coefficient k is proposed, and then the local buckling critical stressf olcan be calculatedconveniently.