Finite element mesh generation for fracture mechanics in 3D coupled with ansys®: elliptical cracks and lack of fusion in nozzle welds

Abstract

Experience indicates that there are many operating pressure vessels with a lack of fusion defects in their nozzle welds. A fitness for service assessment of such flaws is often required. Due to geometrical complexity, finite element analysis is needed, but inserting a 3D crack mesh in such analysis can be complex and time consuming. To overcome this issue, a C/C++ program capable of generating 3D finite element (FE) meshes for certain common crack configurations found in industry, specifically in the nozzle welds of pressure vessels, was created. This mesh can be perfectly coupled to a FE model in ANSYS® and be adapted to many geometric situations. Tests were performed and the numeric values of the K and J-integral results were compared with known solutions, demonstrating good agreement.