Considering the well known advantages of the Direct Strength Method if compared with the Effective Width Method for the design of thin-walled cold-formed steel members, but also the difficulties arising from the necessity to perform computational analysis to rind the actual critical buckling loading which support the DSM design formulation, an alternative design procedure was validated in order to make it simpler and direct the application of the DS principles for the case of local-global buckling interaction. In addition, the proposed formulation make it easier integrating the direct strength principles side-by-side with the EWM, avoiding manipulation of computational programs, at least for the most usual cold-formed shapes. The Effective Section Method was included in the 2009 edition of the revision of the Brazilian code NBR 14762 after extensive calibration against experimental results of columns and beams. The ESM formulation for resistance design keeps the original idealization of "reduced" or "effective" cross-section geometry (A_(ef) for columns and W-(ef) for beams) but, on the contrary of the EWM, these reduced geometrical properties are based on the actual local plate buckling behavior of the member. The option to adopt direct access to local buckling loading by equations and tables is also available in the Brazilian code. This solution improved the attractiveness of the ESM and allowed easy way to apply direct strength principles, as well as assured more accurate design rules if compared with the classical EWM prescriptions.
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