Relationship between strain distribution and molding geometry during metal additive manufacturing process

Abstract

In this study, a strain generated in a molded part during metal additive manufacturing process was investigated by in- situ measurement using a digital image correlation method that utilizes the unevenness pattern on surface of a molded object. During the molding process, large strain was measured at the top of a molding part. This is thought to be related to the distance between a base plate and the top of a molding object. A base plate was fixed at the four corners with screws and had high stiffness. However, by progressing of the molding process, the lower part of a molding object supported distortion of the upper part instead of a base plate and resulted in increasing strain due to lower stiffness in the lower part. Strain generated in the molding object tended to decrease by increase in height of the molding object, which might be due to increase in cross-sectional secondary moment of the molding object.