Investigation on ultimate strength of thin-walled steel single shear bolted connections with two bolts using finite element analysis

Finite element analysis (FEA) procedures for predicting the structural behaviors of single shear bolted connections in cold-formed stainless steel have been recommended through previous numerical studies conducted by T.S Kim for Kuwamura's test results and are also introduced briefly in this paper. It was shown that ultimate behaviors such as ultimate strength, failure mode and curling occurrence by FEA were in a good agreement with those of test results. Based on the reasonable prediction accuracy of numerical approach, parametric studies on single shear two-row bolted connections with extended variables; plate thickness, end distance in the direction of load and edge distance perpendicular to the direction of load is conducted in order to consider the strength reduction effect due to curling. It can be found that Kuwamura's equations, which has been specified by Stainless Steel Building Association of Japan (SSBA) design manual are more valid for estimating the ultimate strength of bolted connections with no curling when compared to other design standards, whereas for connections curled in test and FEA results, since SSBA design standard does not consider the curling effect, the ultimate strength of connection was overestimated. Consequently, revised design formulae considering the effect of curling on bolted connection are proposed in this paper using correlations between strength reduction ratio and plate thickness. Furthermore, the validation of the design equations is verified through comparisons with existing test and additional FEA results.