Hi Abhishek and Colin, Depending on what the notch looks like, we might be able to use extrusion with variable number of cells to represent it; e.g., the following might work if the notch is simple enough: mesh = ExtrudedMesh(annulus, layers=[[0, N], [0, N], ... [1, N], # <- notch ... [0, N]]) https://www.firedrakeproject.org/extruded-meshes.html#variable-numbers-of-me... Extruded Meshes in Firedrake — Firedrake 0.13.0+4443.g8749e443 documentation<https://www.firedrakeproject.org/extruded-meshes.html#variable-numbers-of-mesh-cell-layers> Introduction ¶. Firedrake provides several utility functions for the creation of semi-structured meshes from an unstructured base mesh. Firedrake also provides a wide range of finite element spaces, both simple and sophisticated, for use with such meshes. www.firedrakeproject.org Best, Koki ________________________________ From: firedrake-bounces@imperial.ac.uk <firedrake-bounces@imperial.ac.uk> on behalf of Cotter, Colin J <colin.cotter@imperial.ac.uk> Sent: Friday, May 7, 2021 6:39 AM To: Venketeswaran, Abhishek (FN) <Abhishek.Venketeswaran@netl.doe.gov> Cc: firedrake <firedrake@imperial.ac.uk> Subject: Re: [firedrake] Delete element to model notch/crack in an Extruded Mesh Hi Abhishek, You can’t delete individual elements from an extruded mesh, since they are just 2D meshes as far as DMPlex is concerned. The idea of extruded meshes is to increase performance by having the mesh structured in the extruded direction. all the best cjc On 6 May 2021, at 22:37, Venketeswaran, Abhishek (FN) <Abhishek.Venketeswaran@netl.doe.gov> wrote: Hi, I have created a hexahedral mesh of a pipe by extruding an annulus meshed with quadrilateral elements. I need to model a notch or crack by deleting elements from the mesh. I looked into mesh.py but I am not confident of what functions I need to look into. Can anyone help me with a simple code to delete an element for a given extruded mesh or list the functions that I should look into? Thanks -- Abhishek Venketeswaran NETL Research Associate - ORISE National Energy Technology Laboratory Department of Energy abhishek.venketeswaran@netl.doe.gov Work: 412-386-4833 Mobile: 716-507-7890 www.netl.doe.gov<http://www.netl.doe.gov> <Outlook-qlsfbeig.png> _______________________________________________ firedrake mailing list firedrake@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/firedrake