Flexural Buckling Behavior of Wire‐Arc Additively Manufactured Stainless Steel Bars

Abstract Wire‐Arc Additive Manufacturing (WAAM) is a metal 3D printing technology suitable to realize large‐scale elements of complex form. The deposition strategy of metal can be either layer‐by‐layer, used for shells and solid parts, or dot‐by‐dot, resulting in bars and lattice structures. This latter has in particular the potential to realize new resource‐efficient lightweight structural elements with reduced material use. This paper investigates the structural performance of stainless steel bars produced via Wire‐and‐Arc Additive Manufacturing (WAAM) using a dot‐by‐dot deposition strategy. The study addresses the challenges posed by the non‐uniform geometry and mechanical properties of WAAM bars, focusing on their tensile, flexural, and buckling behavior. Experimental tests, including tensile, three‐point bending, and compression, were conducted on bars with varying build angles and slenderness. Results show that WAAM bars achieve yield and ultimate strengths comparable to conventional 304L stainless steel, but with a notably lower and more variable Young's modulus (100–130 GPa), influenced by build orientation and crystalline texture. Three modeling approaches were assessed: nominal, effective, and real geometry (via 3D scanning), with finite element analysis highlighting the impact of geometric irregularities on flexural stiffness and buckling resistance. The findings support the development of design rules for WAAM structural elements, advancing their application in resource‐efficient, optimized metal structures.