Observations and Comments Pertaining to CAN/CSA-S136-M89

Contained in this paper are the results of two separate studies, namely, 1) partially stiffened compressive elements of both edge and single intermediate stiffened flanges and 2) deflection determination of multi-web deck profiles. Both of these studies were based on the Canadian cold formed steel design standard (CAN/CSA-S 136-M89), with the results also applicable to the AISI specification. In the case of partially stiffened compressive elements, discontinuities in effective width estimates for sections with similar flanges and stiffeners were observed, resulting from a sudden change in the behavioural states. Recommendations are presented to rectify this discontinuity and at the same time simplifying the analysis procedure. Regarding the second study, the some-what lengthy alternative approach in S136 for determining the effective width of multi-web profiles for deflection determination has been investigated. Recommendations are presented for a new approach which is consistent with the general unified effective width concept, i.e. the basic effective width expression is used with a variable plate buckling coefficient