Structural performance of wire arc additively manufactured duplex stainless steel single-lap shear bolted connections

This paper investigates the structural performance of wire arc additively manufactured ER2209 duplex stainless steel (DSS) single-lap shear bolted connections. A comprehensive test campaign was conducted, involving a total of 43 WAAM ER2209 DSS single shear bolted connections with variations in bolt hole positions, surface conditions (i.e. machined or unmachined) and loading orientations relative to the printing direction. The geometric dimensions of the test specimens were meticulously measured using a non-contact 3D laser scanner prior to tensile tests. Detailed analyses on the observed failure patterns, load-displacement curves and resistances considering both deformation and strength criteria are presented. The effects of bolt hole position, surface condition and loading orientation of the WAAM DSS plate on the structural behavior of the single shear bolted connections are analyzed. Given the absence of specific design rules for WAAM DSS bolted connections, the applicability of existing design rules originally developed for conventionally manufactured carbon/stainless steel bolted connections is examined. The experimentally obtained resistances are compared with predictive resistances derived from the Eurocode 3 (prEN 1993–1-8 and prEN 1993–1-4), the American Specification (ANSI/AISC 370–21), and recent design recommendations proposed in the existing literature. The findings underscore that existing design rules tend to provide rather conservative resistance predictions for WAAM ER2209 DSS single shear bolted connections, particularly when employing the deformation criterion, while the design equations proposed in existing literature yield general conservative and the most accurate resistance predictions in strength criterion.