Print Email Facebook Twitter QR-patterns Title QR-patterns: artefacts in multiresolution topology optimization Author Gupta, D.K. (TU Delft Computational Design and Mechanics) Langelaar, Matthijs (TU Delft Computational Design and Mechanics) van Keulen, A. (TU Delft Computational Design and Mechanics) Date 2018 Abstract Recent multiresolution topology optimization (MTO) approaches involve dividing finite elements into several density cells (voxels), thereby allowing a finer design description compared to a traditional FE-mesh-based design field. However, such formulations can generate discontinuous intra-element material distributions resembling QR-patterns. The stiffness of these disconnected features is highly overestimated, depending on the polynomial order of the employed FE shape functions. Although this phenomenon has been observed before, to be able to use MTO at its full potential, it is important that the occurrence of QR-patterns is understood. This paper investigates the formation and properties of these QR-patterns, and provides the groundwork for the definition of effective countermeasures. We study in detail the fact that the continuous shape functions used in MTO are incapable of modeling the discontinuous displacement fields needed to describe the separation of disconnected material patches within elements. Stiffness overestimation reduces with p-refinement, but this also increases the computational cost. We also study the influence of filtering on the formation of QR-patterns and present a low-cost method to determine a minimum filter radius to avoid these artefacts. Subject ArtefactsArtificial stiffnessMultiresolution topology optimizationp-refinementQR-patterns To reference this document use: http://resolver.tudelft.nl/uuid:a36fed17-1aba-4c75-8f27-877de94ccad2 DOI https://doi.org/10.1007/s00158-018-2048-6 ISSN 1615-147X Source Structural and Multidisciplinary Optimization, 58 (4), 1335-1350 Part of collection Institutional Repository Document type journal article Rights © 2018 D.K. Gupta, Matthijs Langelaar, A. van Keulen Files PDF Gupta2018_Article_QR_patt ... ltires.pdf 2.41 MB Close viewer /islandora/object/uuid:a36fed17-1aba-4c75-8f27-877de94ccad2/datastream/OBJ/view