Residual stress characterization of a fabrication weld from the VICTORIA-Class submarine pressure hull : Revealing the unseen

Explicit understanding of the residual-stress character of primary submarine pressure hull weldments will improve the fidelity of numerical analysis and experimentation supporting operational envelope and design life. A length of circumferential-seam closure weld was contained within a section of hull plate removed from the HMCS VICTORIA during the extended docking work period (EDWP) refit operations. This has provided a rare opportunity for detailed characterization of the as-received condition of this common weld-type from original vessel assembly. In collaboration with the Canadian Neutron Beam Centre of the National Research Council (NRC), a program was conducted to study this weld using neutron diffraction. Neutron diffraction is able to survey nondestructively through the section thickness, providing a three-dimensional characterization, while leaving the specimen intact for complementary study by other methods. Results indicate tensile stress peaks of up to 80% of the base-material yield stress. Understanding the three-dimensional behaviour of residual stress in this type of weld provides a valuable resource to the numerical modelling community. The results can also support fatigue and fracture experimental work and serve to confirm and improve the interpretation of the existing body of \u2018\u2018surface-only\u2019\u2019 work conducted on similar welds.Une compr\ue9hension explicite de la nature de la charge r\ue9siduelle de la coque pressuris\ue9e primaire d\u2019un sous-marin assembl\ue9e par soudure va am\ue9liorer la qualit\ue9 de l\u2019analyse num\ue9rique et exp\ue9rimentale visant \ue0 am\ue9liorer sa vie op\ue9rationnelle. Une longueur de soudure d\u2019un joint en circonf\ue9rence faisait partie d\u2019une section de la coque pr\ue9lev\ue9e sur le HMCS Victoria pendant les op\ue9rations de r\ue9paration extensives de longue dur\ue9e (EDWP). Ceci nous a fourni une rare opportunit\ue9 pour caract\ue9riser en d\ue9tail la condition telle que re\ue7ue de ce type de soudure commune dans la construction originale du vaisseau. En collaboration avec le Centre Canadien de faisceaux de neutrons du Conseil National de Recherche, nous avons \ue9tudi\ue9 cette soudure par diffusion de neutrons. La diffusion de neutron a pu sonder de fa\ue7on non destructive toute l\u2019\ue9paisseur de la section, fournissant une image tridimensionnelle, tout en laissant le sp\ue9cimen intact pour des analyses compl\ue9mentaires utilisant d\u2019autres m\ue9thodes. Les r\ue9sultats indiquent des efforts sous traction jusqu\u2019\ue0 80% de la limite d\u2019\ue9lasticit\ue9 du mat\ue9riau de base. La compr\ue9hension du comportement tridimensionnel de la charge r\ue9siduelle dans ce type de soudure fournit de l\u2019information importante \ue0 ceux qui mod\ue9lisent num\ue9riquement ces structures. Les r\ue9sultats peuvent justifier de pousser des travaux exp\ue9rimentaux sur la fatigue et la rupture et servent \ue0 confirmer et \ue0 am\ue9liorer les m\ue9thodes d\u2019examen en surface seulement que l\u2019on fait sur des soudures du m\ueame type.Peer reviewed: YesNRC publication: Ye