Finite Element Analysis on Strength of Cold-Formed Ferritic Stainless steel Connections with Four Bolts Considering Curling Influence

Background: Recent patents suggests that the use for architectural applications of stainless steel as structural members has increased in recent years due to its desirable characteristics such as high ductility, attractive appearance, fire resistance and corrosion resistance. However, relatively high initial cost of stainless steels compared with carbon steels is an obstacle to use widely in building construction field. The material cost of stainless steel tends to be determined by the alloy content, particularly nickel. Therefore, ferritic stainless steels with little or no nickel can provide many benefits similar to the more conventional grades (austenitic and duplex). Since the current design rules for stainless steel bolted connection follow those of carbon steel with partly limited modification, they can't properly utilize the advantage of stainless steel material properties. Method: This paper describes experimental and numerical investigation on behavior of ferritic stainless steel single shear bolted connections. Numerical models have been developed and validated against test results. Objective: The validated models were subsequently used to perform extensive parametric studies to investigate curling effect on ultimate strength of bolted connection. Results: The analysis results were compared with the strengths calculated by the current design equations. It is shown that the current design rules don't exactly predict ultimate strength of curled specimens. Conclusion: Therefore, design strength equation considering curling effect was proposed through statistical analysis and estimated by comparison with analysis results.