Behavior and Design of Seam-Welded Stainless Steel Circular Hollow Section Flexural Members

In an experimental study, a series of tests was performed on seam-welded structural stainless steel circular hollow sections (CHS) subjected to bending. The test program included various cross section geometries of CHS that covered a range of structural responses. Three-dimensional nonlinear finite-element (FE) models (ABAQUS) were established and verified with the experimental results accounting for material nonlinearity and manufacturing distortions. Close agreement was achieved between the test and finite-element analysis results in terms of load-deformation response and ultimate strength. The test and finite-element strength results with additional FE results generated for CHS models not considered in the test are compared with the strengths predicted using the American, Australian, and European specifications for cold-formed stainless steel structures. In light of the experimental/numerical results and code recommendations, strength and cross section classification criteria for stainless steel circular hollow section members in bending were examined. The results showed that significant improvements are possible for cross section slenderness limits provided by the current specifications.