Initial stress-based residual stress and distortion computation for part scale laser powder bed fusion

Abstract

Prior estimation of residual stress and distortion for part scale laser powder bed fusion (LPBF) is a tedious task but is required to avoid build failures and improve manufacturing yield. A novel approach is presented here to enable numerical modeling of part scale stress with peak longitudinal and transverse residual stress for a deposited layer as initial stress, which are obtained from back-of-the-envelope functional relations. The numerically computed results of residual stress and distortion are tested rigorously with the corresponding experimentally measured results from literature for part scale LPBF of common powder alloys. The proposed approach depicts a substantive tool for full field residual stress and distortion estimation in part scale quickly and reliably with practical computational resource.