In situ monitoring of wire and arc additive manufacturing by digital image correlation: a case study

This paper presents a case study of in situ monitoring during wire and arc additive manufacturing (WAAM) process by using digital image correlation (DIC). A feasibility study is carried out aiming at proposing a suitable experimental set-up for in situ measurements during a WAAM process. In this work a stainless steel AISI316L was used to manufacture parallelepiped with nominal dimensions of 130 × 25 mm. The issues related to high-intensity electromagnetic radiation and melted metal projections with regard to image acquisition were addressed. The in situ evolution of the strain field generated in the part during the manufacturing process are shown and discussed. The results show that the horizontal strain component (εxx) presents higher values than the vertical strain component (εyy). The spatial and temporal strain evolution were then analysed at given locations. Strain gradient patterns were clearly observed near the layers underlying material deposition during the process. These results shown the feasibility of using in situ DIC monitoring during the WAAM process.