Weld seams of cruciform specimens were digitized in 3D using a high-precision fringe projection scanner. Based on these digital twins, finite element analyses (FEA) were performed to determine stress distributions in highly loaded regions at the weld toe, known as hot spots critical for fatigue life. Initially, maximum element stresses based on finite element analyses at four weld transitions were compared with experimental data, showing poor correlation. By increasing the number of evaluated elements and averaging the 5,000 most highly stressed elements at the critical transition, good agreement with the experimental S–N curve was achieved. The slope and scatter of the simulated S–N curve also matched well with test results. Due to the linear-elastic material model, stresses were overestimated, as microplastic effects at the weld toe were not considered. A post-processing algorithm SESAM was developed to further analyse and quantify results. It allows flexible parameter selection and enables, for the first time, the 3D quantification of hot spots or micro-notches and their stress distributions, providing a basis for fracture mechanics approaches such as crack growth analysis or the application of the mathematical equation-concept.      «

Weld seams of cruciform specimens were digitized in 3D using a high-precision fringe projection scanner. Based on these digital twins, finite element analyses (FEA) were performed to determine stress distributions in highly loaded regions at the weld toe, known as hot spots critical for fatigue life. Initially, maximum element stresses based on finite element analyses at four weld transitions were compared with experimental data, showing poor correlation. By increasing the number of evaluated el...     »