Experimental and numerical study of the flexural behavior of steel–concrete-steel sandwich beams with corrugated-strip shear connectors.

• This study was performed to investigate of using the plug weld of an inaccessible end of CSCs on the failure modes and flexural behavior in SCSbeams contrast to one-end welded ones. • The specimens were numerically modeled and verified to investigate parameters including the thickness of the concrete, the number of rows of CSCs, the type of connection of the CSCs, faceplates thickness, concrete thickness, CSCs width and thickness on structural behavior of SCS beams. • Based on the relationships of reinforced concrete beams, a modification factor was proposed to predict the final strength of SCS beams. An important weakness of the steel–concrete-steel (SCS) sandwich structure with corrugated-strip shear connectors (CSCs) is the lack of access to make two-end welding of CSCs to the steel faceplates. In the present study, the use of plug weld was proposed to weld an inaccessible end of the CSCs. To evaluate the partial two-end welded CSCs, the SCS flexural beams including one specimen with one-end welded and four specimens with two-end welded were fabricated and tested under concentrated quasi-static loading. Then, failure modes and force–displacement diagrams were analyzed by examining parameters including the thickness of the concrete core, the number of the rows of CSCs and the type of connection of the CSCs (one-end or two-end welded). To further investigate, numerical model of the experimental specimens were created and validated. Using numerical models, the effect of parameters of steel faceplates thickness, concrete core thickness, CSCs breadth and thickness was investigated. The results showed that the use of partial two-end welded CSCs with plug welding, in addition to increasing the ultimate strength by about 30%, also provided more energy absorption than samples with one-end welded CSCs. Also, in most samples with two-end welded CSCs, the flexural failure mode was dominant over the shear failure. Finally, based on the relationships of reinforced concrete beams, a correction factor was proposed to predict the ultimate strength of the samples, which was in acceptable agreement with the experimental and numerical results. [ABSTRACT FROM AUTHOR]