Study of fracture resistance of a weldment with a propagating crack

• Published in: The International journal of pressure vessels and piping Vol. 168; pp. 210 - 218
• Main Authors: Krishnan, S.A., Sarmah, Abhishek, Moitra, A., Sasikala, G., Rao, C. Lakshmana, Albert, Shaju K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2018
• Subjects: Heterogeneous CT specimen and FEM analysis; Modified J-integral; Weldment; Modified J-integral; Heterogeneous CT specimen and FEM analysis; Weldment
• ISSN: 0308-0161; 1879-3541
• DOI: 10.1016/j.ijpvp.2018.10.018

The overall fracture resistance of a weldment with a propagating crack across the weld, HAZ and base material has been evaluated for a AISI type 316LN stainless steel (SS), based on coupled experimental-finite element analysis. Compact type (CT) specimens with initial crack tip in the weld, heat affected zone (HAZ) and base material have been tested to evaluate J-integral resistance curve (J-R curve) across the weldment. Towards evaluating the J-integral for a heterogeneous material, elastic component of J was determined using equivalent Young's modulus (Eeq) in terms of instantaneous compliance and crack depths. Simultaneously, finite element (FE) analyses have been carried out to estimate J-integrals for various contours across the weldment and for nodal singularities along interfaces, leading to a modified J-integral for overall weldment. The reasonable agreement among experimental J values from different regions with the modified J-integral values gives credence to this procedure to predict overall fracture resistance across the weldment over a heterogeneous microstructural gradient. •Proposed equivalent Young's modulus based elastic J-estimation procedure.•Experimental investigation of J-R curve across the 316L(N) SS weldment.•Modified J-integral for crack propagating across the weldment from FEM simulations.•The reasonable agreement between experimental and modified J-integral values.