Toward accurate prediction of partial-penetration laser weld performance informed by three-dimensional characterization – Part I: High fidelity interrogation

The mechanical response of laser welds in complex load states can be highly variable, underlying the need for models that can accurately predict mechanical behavior to ensure component performance. In Part I of this work, a series of partial penetration welds of 304L stainless steel have been characterized in three dimensions using micro-computed tomography (μCT). The effect of segmentation approaches for handling raw three-dimensional data has been studied in detail. Such characterization enables for comprehensive analysis of the physical distribution and shape of porosity within the weld as well as details on the geometry of the joint, which are used in conjunction with mechanical testing to understand the impact of these factors on weld performance. Joint geometry, in particular the prescribed gap between the plates, has a large impact on the tensile response of weldments, which can be understood to primarily depend on the local load state that develops around the joint. Using high-fidelity three-dimensional data, the mechanical response of individual weldments, including the peak load and displacement to failure, can be accurately predicted using finite element simulations. The details of the modelling approach, and its sensitivity to various idealizations, are the focus of Part II of this work.