Influence of internal volumetric imperfections on the tearing resistance curve of welded Single Edge notched Tension (SENT) specimens. (January 2022)

• Record Type: Journal Article
• Authors: Adriano, Vitor; De Waele, Wim; Cardon, Eleine; Boone, Matthieu N.; Hertelé, Stijn
• Is Part Of: Engineering fracture mechanics. Volume 259(2022)
• Publication Date: 2022-01
• Subjects: Weld imperfections -- Fracture toughness -- Tearing resistance curve -- Unloading compliance -- Direct current potential drop; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2021.108162
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: Fracture toughness tests were performed on welded SENT specimens with imperfections. Imperfections were characterized by high-resolution computed tomography scans. Resistance curves were significantly impacted by the presence of imperfections. Direct current potential drop showed to be a robust crack sizing technique. Abstract: The acceptance of volumetric weld imperfections is subjected to workmanship guidelines, which are subjective quality criteria loosely related to fitness for purpose assessments. However, the relative impact of such imperfections may be accentuated in fracture toughness tests, given the relatively small dimensions of the test specimens. This study analyses the impact of weld volumetric imperfections on the outcome of fracture toughness tests. Single Edge Notched Tensile (SENT) specimens were machined from steel plates joined by robotic Metal Inert Gas (MIG) welding. The specimens contained different levels of volumetric imperfections which were characterized by high-resolution X-ray Computed Tomography (µCT) scans. Single specimen fracture toughness tests were conducted and crack growth was monitored by applying both the Unloading Compliance (UC) technique and the Direct Current Potential Drop (DCPD) technique. Tearing resistance curves (R-curves) were constructed based on UC and DCPD data. Results showed that specimens containing volumetric imperfections acceptable by workmanship guidelines may yield significantly inferior fracture initiation toughness values compared to imperfection-free specimens.