Latest news archive: Automatic mesher
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Strand7’s Automatic Mesher: A Progress Report
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19-June-2000
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For the past 3 years, the development team at G+D Computing has been very busy developing the automatic mesh generators for Strand7 - consisting of a quad-dominant surface mesher together with a tetrahedral solid mesher. Both have been developed and implemented from scratch based on our own research and development. Over the past twelve months our efforts in this area have intensified and the current phase of the project is now nearing completion.
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Much of the development work has centred around automatically generating good quality meshes with a minimum amount of user interaction from arbitrary surface data. Both analytical (e.g. plane, cylinder, cone, torus, sphere) and NURBS surfaces are supported. The meshers also address a number of potential CAD anomalies such as T-junctions (where multiple surface patches meet a single surface patch) and very narrow surface segments. The surface mesher can create both linear (Quad4) and quadratic (Quad8) quadrilaterals. The tet mesher can generate both linear (Tetra4) and quadratic (Tetra10) elements.
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The Strand7 mesher supports the ACIS file format known as "SAT" for the input of geometry data. The SAT format is currently supported by a number of CAD systems such as AutoCAD and SolidWorks. For simplified geometry, Strand7's own basic geometry input can be used.
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We have been using the meshers for the past few months for both our own consulting work and as a service to our supported Strand7 users. The meshes shown below have all been generated automatically in Strand7 Alpha Release 2.0. The geometry has been imported from CAD using the SAT file format.
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Strand7 Release 2.0 will be available before the end of this year. In the next few months, a Beta release will be issued to a number of Strand7 users. In the meantime, if you are a
supported Strand7 user, we are offering to automatically mesh your models for you. This will not only reduce your analysis times, it will also help us test the mesher and improve its robustness and reliability. If you have something that you would like meshed, please send us the CAD file, preferably in SAT format (we can also accept IGES, DWG, SLDPRT).
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The geometry for this 2D model was constructed in Strand7. The mesher generated 2919 2D elements.
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The geometry for this 2D model was also constructed in Strand7. The mesher generated 1516 2D elements.
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This model of a lever was saved as a SAT file in SolidWorks and imported into Strand7. The surface mesher generated 2468 quadrilateral plate elements. This mesh was fed into the tet mesher which used the quadilaterals to generate 16166 tetrahedral elements.
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This is an aluminium seat casting for a train seat. The geometry was created in SolidWorks and meshed as a solid in Strand7. The number of triangular faces is 25038, generating 74890 tetrahedral elements. Model courtesy of Transform Rail Interiors.
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This is a simple CAD model generated as a tutorial in SolidWorks. The surface mesh consists of 1860 triangular elements. The solid mesh consists of 5201 tetrahedral elements.
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The surface mesh for this blade was constructed in a CAD system and imported into Strand7 as a series of 3-node polygons. Strand7 was used to construct the solid mesh consisting of 7043 tetrahedral elements. This mesh illustrates Strand7's ability to create a solid mesh on a surface where there is a very large difference in the area of the surface elements. In this case, the ratio of largest element area to smallest element area is 297000.
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This mesh consists of 109797 tetrahedral elements. A particular feature of this mesh is the thin plate-like sections. Here a single element correctly spans the through-thickness direction.
Model courtesy of K Walsh Consulting.
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This image shows both the quadrilateral surface mesh (7453 plates) and the tetrahedral solid mesh (27858 tets) automatically generated on the housing. Model courtesy of Svedala Australia.
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Three parts were automatically meshed to create this model of the pliers, consisting of 12681 tetrahedral elements.
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This quarter model of a piston consists of 14360 tetrahedral elements.
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This model is one of the standard AutoCAD surface models. The resulting surface mesh consists of 7822 predominantly quad elements.
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