Print Email Facebook Twitter An improved stress recovery technique for the unfitted finite element analysis of discontinuous gradient fields Title An improved stress recovery technique for the unfitted finite element analysis of discontinuous gradient fields Author Zhang, J. (TU Delft Computational Design and Mechanics) Aragon, A.M. (TU Delft Computational Design and Mechanics) Date 2022 Abstract Stress analysis is an all-pervasive practice in engineering design. With displacement-based finite element analysis, directly-calculated stress fields are obtained in a post-processing step by computing the gradient of the displacement field—therefore less accurate. In enriched finite element analysis (EFEA), which provides unprecedented versatility by decoupling the finite element mesh from material interfaces, cracks, and structural boundaries, stress recovery is further aggravated when such discontinuities get arbitrarily close to nodes of the mesh; the presence of small area integration elements often yields overestimated stresses, which could have a detrimental impact on nonlinear analyses (e.g., damage or plasticity) since stress concentrations are just a nonphysical numerical artifact. In this article, we propose a stress recovery procedure for enhancing the stress field in problems where the field gradient is discontinuous. The formulation is based on a stress improvement procedure (SIP) initially proposed for low-order standard finite elements. Although generally applicable to all EFEA, we investigate the technique with the Interface-enriched Generalized Finite Element Method and compare the procedure to other post-processing smoothing techniques. We demonstrate that SIP for EFEA provides an enhanced stress field that is more accurate than directly-calculated stresses—even when compared with standard FEM with fitted meshes. Subject enriched finite element analysisinterface-enriched generalized FEMstress improvement procedurestress recovery To reference this document use: http://resolver.tudelft.nl/uuid:d143227b-7d20-4fd3-9176-353874eb3e53 DOI https://doi.org/10.1002/nme.6825 ISSN 0029-5981 Source International Journal for Numerical Methods in Engineering, 123 (3), 639-663 Part of collection Institutional Repository Document type journal article Rights © 2022 J. Zhang, A.M. Aragon Files PDF Numerical_Meth_Engineerin ... alysis.pdf 5.56 MB Close viewer /islandora/object/uuid:d143227b-7d20-4fd3-9176-353874eb3e53/datastream/OBJ/view