Effect of Porosity Shape, Size and Distribution on Stress Intensity Factors in Spot Welded Joints: A Finite Element Study

In this study, the influence of porosity on crack initiation behavior in welded structures subjected to spot welding was investigated. Three-dimensional (3D) finite element analyses were conducted using the ABAQUS finite element software under mechanical stress. The stress intensity factors (SIF) in opening and moving modes were computed employing the finite element technique. A comprehensive analysis of various parameters, including mechanical load, crack size, porosity form, porosity size, porosity-crack interaction, and crack orientation, was carried out. This investigation was approached as a mixed-mode, plane stress, and linear elastic fracture mechanics problem with a focus on the passive voice. The results demonstrated that the stress intensity factor is not only dependent on the magnitude of the applied mechanical loading but also on factors such as crack size, porosity form, defect-defect interaction, and crack orientation. Additionally, it was observed that both the size and form of porosity play a significant role in influencing the stress intensity factors. This research contributes to the understanding of fracture mechanics in welded structures and provides valuable insights for enhancing the structural integrity and reliability of such systems.