Effect of Corner Strength Enhancement on Shear Behaviour of Stainless Steel Lipped Channel Sections

During the cold-forming process of manufacturing, stainless steel sheets undergo plastic deformations, in particularly around corner regions of press braked sections. These plastic deformations lead to significant changes in material properties of stainless steel compared to its flat sheet properties. Consequently, yield strength and ultimate strength increments can be envisaged and this process is termed as cold working. Stainless steel exhibits significant level of strain hardening under plastic deformations. This is the main reason for these strength enhancements. In the structural design process of stainless steel sections, these strength increments are required to be considered to harness the benefits arising from it. Therefore, previous research proposed predictive models for these strength enhancements. In this context, the effect of corner strength enhancement on press-braked stainless steel lipped channel sections under shear was examined in this paper. 120 finite element models were developed. Different corner radii and section thicknesses were taken into account. Results highlighted that the effect of cold working on the shear capacity of stainless steel lipped channel sections is more significant in compact sections compared to slender sections where up to 9% increment was observed. Further analysis was conducted using 40 finite element models to highlight the inelastic reserve capacity available in compact stainless steel lipped channel sections in shear. From the results, it was concluded that when web slenderness is less than 0.25 more than 40% shear capacity increment can be achieved due to strain-hardening of stainless steel.