Lateral Buckling of Singly Symmetric Beams

General solutions for the elastic lateral buckling moment of singly symmetric sections are studied. The studies include the effect of the location of the load on the section as well as the effect of moment gradients on the lateral buckling moment. Design provisions are outlined for the case of moment gradients

Local and Distortional Buckling of Thin-walled Beams

Recent research has characterized the behavior of panel beams with laterally unsupported compression flanges as either a complex local buckling mode or an overall buckling mode. Tests have shown that the behavior of the unsupported flange and web is similar to that of lateral buckling, except, rotation is enforced along the axis of the web and the tension flange--a behavior which may be described as distortional buckling. In the work described here, an analytical expression is presented for computing the elastic distortional buckling stress based on a model which treats the web and compression flange as an elastically restrained beam. The formulation is similar to those for lateral and torsional buckling. The effect of web local buckling on the rotational restraint of the outstanding leg is modeled explicitly using the effective width equations described in the AISI Cold-Formed Steel Design Manual. The analytical results from the distortional buckling expression are shown to agree reasonably well with numerical results generated from an elastic fInite strip buckling program (BFINST6). A design approach is suggested for estimating the ultimate moment capacity of a section subjected to the interaction between local and distortional buckling

Flexural Capacity of Continuous Span Standing Seam Panels: Gravity Load

The standing seam panel is one of the most practical and economical roofing systems developed in recent years. Construction of the roof system requires that the panel legs be overlapped and crimped. Under gravity load, the crimped outstanding leg of the connected panels may be subject to distortional buckling. A design method was previously suggested for estimating the distortional buckling strength of the outstanding leg of a single simply supported standing seam panel. In this paper, an approximate method is present for estimating the capacity of a system of interconnected continuous span standing seam panels. Experimental results for three full-scale continuous span tests and one full-scale simple span test sbow that the approximate method provides a relatively accurate estimate the maximum capacity for a system subject to gravity load

Design of Cold-formed Steel Plain Channels

This paper gives an overview of the design procedures formulated for plain channels. These formulations are based on experimental and finite element studies. The scope of the work covers laterally braced beams, columns and beam-columns of cross-sections in the range of practical applications by the industry. The recommendations treat members that are made up of elements that may be in the post-buckling or post yielding range

Experiments on Lipped Channel Flexural Members

A series of tests were conducted on lipped channel flexural members to study the behavior of edge stiffened elements. The details and the results of these tests as well as tests by others are discussed in this paper. All the test results are compared with those predicted by the AISI Specification