Thermal-mechanical evolution of arc additive manufacturing process through digital image correlation

In this study, the digital image correlation (DIC) method was used to obtain the full-field strain in the arc additive manufacturing process successfully, and the evolution process of temperature field, stress field and strain field during the deposition of 304 stainless steel thin-walled parts was analyzed by combining infrared thermal imager and finite element method. The results show that the temperature field and strain field simulated by finite element are in good agreement with the data measured by additive experiment, and the principal strain of the deposited component shows a trend of periodical accumulation and increase with temperature. During the arc additive manufacturing process, the area near the molten pool expands under heat, and the molten pool area is tensile stress. After the deposition, the stress inside the component is mainly compressive stress, presenting a “multi-peak” symmetrical distribution.