Simplified Approach For Fracture Integrity Assessment Of Bimetallic Girth Weld Joint

Welded pipes are widely employed in many oil and gas applications. Engineering Critical Assessment (ECA) shall be performed in order to establish acceptance levels for revealed or postulated flaws in new or existing constructions. Although methods for assessing the acceptability of flaws in all types of structures are presented in codes and standards, such as BS7910 [1], API579-1 [2], R6 [3], DNV OS-F101 [4], the approaches are typically derived by simplified geometries as plate solutions, simplified material assumption, and simplified load condition as uniaxial load condition. Dedicate numerical solution are more accurate and would improve the assessed results. But the use of appropriate conditions in the full ECA requires several specific Finite Element Analysis (FEA) which are able to identify the Crack Driving Force (CDF) for each postulated defect geometry, material assumption and load conditions. The purpose of this paper is to propose a simplified method, into a standard procedure (similar to BS7910 [1]), minimizing numerical analyses, to guaranty the safety against fracture of many kind of weld joint under non-conventional condition (such as generic weld joint geometry and/or weld joint subjected to combined axial force, bending moment and internal over pressure which are not contemplate in current code and for which dedicated FEA are recommended). ABREVIATIO