**Design and Parameter Identification of Wire and Arc Additively Manufactured (WAAM) Steel Bars for Use in Construction**

**Johanna Müller 1,\*, Marcel Grabowski 2, Christoph Müller 3, Jonas Hensel 1,\*, Julian Unglaub 2,\*, Klaus Thiele 2, Harald Kloft 3 and Klaus Dilger 1**


Received: 6 June 2019; Accepted: 25 June 2019; Published: 27 June 2019

**Abstract:** Additive manufacturing (AM) in industrial applications benefits from increasing interest due to its automation potential and its flexibility in manufacturing complex structures. The construction and architecture sector sees the potential of AM especially in the free form design of steel components, such as force flow optimized nodes or bionic-inspired spaceframes. Robot-guided wire and arc additive manufacturing (WAAM) is capable of combining a high degree of automation and geometric freedom with high process e fficiency. The build-up strategy (layer by layer) and the corresponding heat input influence the mechanical properties of the WAAM products. This study investigates the WAAM process by welding a bar regarding the build-up geometry, surface topography, and material properties. For tensile testing, an advanced testing procedure is applied to determine the strain fields and mechanical properties of the bars on the component and material scale.

**Keywords:** additive manufacturing; construction; WAAM; welding; steel; ESPI; design
