Ultimate strength estimation of short thin-walled cold-formed steel lipped channel section members under eccentric compression loads using yield line analysis

Abstract

The paper presents findings from an analytical-numerical investigation on the use of yield line analysis (YLA) for the upper bound estimation of the ultimate strength of short thin-walled cold-formed steel (TWCFS) lipped channel section members under eccentric compression loads around both the minor and major axes. The post-buckling paths are analysed using the finite difference method (FDM). The post-ultimate failure curves are developed through theoretical models of plastic mechanisms, based on experimental tests and finite element (FE) simulations. The methodology presents the results in terms of load-shortening, alongside comparative diagrams of ultimate strength relative to eccentricity. The ultimate strength is assessed through the estimation of the upper bound using YLA, finite element analysis, experimental testing, and predictions based on the EN 1993-1-3 standard. Conclusions regarding the potential application of upper bound ultimate strength estimation using the YLA approach are drawn, along with discussions on the challenges of implementation and suggestions for future research in this area.