Analyses of distortional buckling of cold-formed sigma purlins using EN1993-1-3

Abstract This technical note presents a study on the calculation of the critical stress of distortional buckling of cold-formed sigma purlins using EN1993-1-3. The discussion is focussed on the determination of the spring stiffness of the stiffened element, a problem which has not yet been addressed in most design codes. Different support conditions at both the tension and compression ends of the web are employed and their influences on the critical stress of distortional buckling of sigma purlins are investigated. Comparison with finite strip analysis indicates that the model having a fixed support for the tension end and a roller support for the compression end of the web provides the best fit to the finite strip analysis.

[1]  Nicholas S. Trahair,et al.  Lateral buckling strengths of cold-formed Z-section beams , 1999 .

[2]  J. Loughlan.  Thin-walled cold-formed sections subjected to compressive loading , 1993 .

[3]  Gregory J. Hancock,et al.  Buckling of thin flat-walled structures by a spline finite strip method , 1986 .

[4]  Dinar Camotim,et al.  Distortional buckling formulae for cold-formed steel C and Z-section members: Part I—derivation , 2004 .

[5]  Gregory J. Hancock,et al.  Distortional Buckling Formulas for Channel Columns , 1987 .

[6]  J. M. Davies,et al.  First-order generalised beam theory , 1994 .

[7]  Long-yuan Li,et al.  An analytical model for analysing distortional buckling of cold-formed steel sections , 2008 .

[8]  J M Davies,et al.  Design of thin-walled purlins for distortional buckling , 1997 .

[9]  Gregory J. Hancock.  Design for distortional buckling of flexural members , 1997 .

[10]  Benjamin W. Schafer,et al.  REVIEW: THE DIRECT STRENGTH METHOD OF COLD-FORMED STEEL MEMBER DESIGN , 2008 .

[11]  R. Kettle,et al.  Local and distortional buckling of cold-formed zed-section beams under uniformly distributed transverse loads , 2006 .

[12]  J. M. Davies,et al.  Second-order generalised beam theory , 1994 .

[13]  Dinar Camotim,et al.  Distortional buckling formulae for cold-formed steel C- and Z-section members: Part II—Validation and application , 2004 .

[14]  Dinar Camotim,et al.  FEM-based analysis of the local-plate/distortional mode interaction in cold-formed steel lipped channel columns , 2007 .

[15]  Long-yuan Li,et al.  Buckling behaviour of cold-formed channel sections under uniformly distributed loads , 2005 .

[16]  Richard Schardt.  Lateral torsional and distortional buckling of channel- and hat-sections , 1994 .

[17]  Benjamin W. Schafer,et al.  Simulation of cold-formed steel beams in local and distortional buckling with applications to the direct strength method , 2007 .

[18]  Gregory J. Hancock.  LOCAL DISTORTIONAL AND LATERAL BUCKLING OF I-BEAMS , 1978 .