# Towards an Automated Design Evaluation Method for Wire Arc Additive Manufacturing
## 1 Introduction  
In recent years, wire arc and additive manufacturing (WAAM) has gained interest for industrial use. WAAM is a group of metal additive manufacturing techniques that utilize arc welding (gas arc, gas tungsten arc, or plasma arc) as the deposition principle [1]. Their key features are reduced production time in comparison to alternative methods, due to higher deposition rates and high material efficiency, thus being a cost-effective additive manufacturing (AM) technique suitable for medium complex parts [2, 3]. Considerable efforts are being made to bring the benefits of WAAM to practical use. Areas of research include the effects of process variants and utilized materials on the process outcome, and surveillance and control of the welding process as well as path planning strategies, which are covered extensively in the literature [4, 5, 6, 7, 8, 9].  
With the availability of new manufacturing techniques equally emerges the need for the adaption of design tools [10]. WAAM differs from other additive manufacturing technologies in its high deposition rate, among other things, which enables the production of large metal parts [11, 12]. Therefore, new design guidelines for WAAM are needed.  
The first propositions of design guidelines have been made [3, 13, 14]; however, to make practical use of these guidelines, designers (1) would have to be familiar with allthese design guidelines, and (2) would have to steadily update their knowledge of new developments in WAAM. Consequently, the use of tools that support design for WAAM is expedient for the design process. Of particular interest in the design stage are software tools that give immediate feedback concerning a draft's manufacturability. Therefore, approaches based on geometric reasoning rather than time-consuming finite element analysis should be favored [15]. Approaches using finite element analysis often focus on simulating the whole manufacturing process [16; 17]. This requires specific knowledge of the whole manufacturing process and the welding tool paths, which is out of the scope of knowledge in the early design stages.  
A traditional geometric method for manufacturability evaluation is the method of Heuvers' circles for casting, of which a first software implementation using a medial axis transformation has been proposed by [PERSON] et al. [15]. Further works expanded on this method to develop manufacturability evaluation algorithms for injection molding [18] or laser-beam-melting AM [19] on which we build to derive a manufacturability evaluation approach suitable for WAAM. Other tools focus on automated path planning from CAD models, but do not check the design for its manufacturability [11].  
An automated manufacturability evaluation for WAAM parts is still a research gap. In this paper, we focus on the analysis of the design of parts, not on simulating the manufacturing process. This gives the designer the possibility of checking the manufacturability in early design stages. Existing tools for automated manufacturability evaluation focus on different manufacturing methods with different design constraints [20] or depend on specific CAD systems and limited recognizable features [21]. Other design tools, as introduced by [PERSON] et al. [22], are focused on supporting design in specific applications and are not directly applicable to other use cases. Our approach is independent of the CAD system used and is not limited to a specific use case. With further research, more detectable geometric features can be implemented in the algorithm to check parts for their WAAM manufacturability.