TrueGrid®Overview
Time Saving Methods with TrueGrid®
TrueGrid® Generates Hexahedral and Quadrilateral Meshes
TrueGrid®'s Powerful Projection Method Made Easy
Quality Mesh with Multiple Block Structure by TrueGrid®
TrueGrid® Integrates Easily into Your System
TrueGrid®'s Friendly and Attractive User Interface
TrueGrid® History
Saves Valuable Time
Expensive three dimensional computer simulations, commonly
used by engineers and scientists, can now be done for a small
fraction of the cost. By most estimates, creating a mesh or grid
for the computer simulation is 80% of the cost. A team of Ph.D.
Mathematicians and Engineers at XYZ Scientific Applications in
Livermore, California have perfected a method which can accomplish
in several days with TrueGrid®
what usually takes a designer several months of work with other
mesh generation programs.
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Part of TrueGrid®'s power comes from giving the designer direct access to the mesh's multi-block structure. This quality mesh of the sphere on the left is formed using 7 block grids in one part. The skeleton of the 7 blocks is shown on the right. There are 7000 hexahedrons in this mesh. It takes less than 1 minute to interactively create this mesh with TrueGrid®, using only 6 commands. Compare this to the time it takes with other tools that require you to start by sub-dividing the geometry. |
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Mesh Generation
TrueGrid® is a computer program used to tessellate a geometric model into hexahedron brick elements and quadrilateral shell elements. The result, called a mesh or a grid, is required by today's FEA and CFD analysis codes which simulate the behavior of structures, fluids, and other complex physical systems. TrueGrid® removes the drudgery of modeling large complex objects, drastically reducing the time involved, while maintaining the highest quality meshes.| The TrueGrid® spring mesh on the right is formed from hexahedron brick elements, but just as easily can be formed from quadrilateral shell elements. In addition, beam elements, used as stiffeners, can be embedded in the mesh. Elements can be linear or quadratic. All of this in one part. |
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Projection Method
TrueGrid®'s projection method (based on projective geometry) eliminates the need for the user to specify the bulk of the details required by other CAD-oriented mesh generators. And this precise projection method can deal with complex geometries -- modeling turbines, pumps, jet engines, wings, transmissions, and even human anatomy. Surfaces and curves can have unrestricted curvature. The user points and clicks on the surfaces and TrueGrid® does the rest. Nodes are automatically distributed on surfaces with boundary nodes automatically placed at the intersections of these surfaces. The distribution of nodes is controlled by sophisticated interpolation and smoothing methods.
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The projection method is performed in three steps. The first step is to define the geometry or import it from a CAD/CAM system. In this example, two cylinders were defined which required two commands in TrueGrid®. |
| In the second step, a crude approximation of the mesh is constructed using rectangular blocks. These blocks must be positioned so that they are close to the geometry. In this example, only 5 commands are used. |
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In the final step, the rectangular faces of the mesh are projected to the appropriate surfaces. Edges required to be on two surfaces are automatically projected to the intersection of the two surfaces. In this example, it takes two commands. All of the commands used in this example were issued by simply using the mouse to point and click. |
Sandia National Laboratory report Solid Model Design Simplification (SAND97-3141 * UC-705) contains further discussion of the issues related to geometry (especially CAD).
Multiple Block Structured Parts
TrueGrid® supports highly structured, multi-block meshes, which produces quality meshes. Simulation codes more quickly produce more accurate simulations using these meshes. Each block is composed of 3D hexahedral, 2D quadrilateral, and 1D linear or quadratic elements arranged in rows, columns, and layers. TrueGrid® has the flexibility to build a multiple block structured mesh conforming to the most complex geometries. Below is an exploded view of a model of a loud speaker with 8 multiple block parts, consisting of both bricks and shells.
(92 Kb)Import The Geometry - Export The Model
Modern designs can be accomplished using a Computer Aided Design system (CAD) or a Solids Modeler. TrueGrid® uses the IGES standard interface to import the geometry and transform the design into a numerical model needed by a simulation code. Because of the superiority of the projection method, no "clean up" is required! (Clean up is only required when using a geometry-based mesh generator.)TrueGrid® also has many types of surfaces and curves using geometric forms, functions, and arbitrary data. In addition, boundary and initial conditions, constraints, and loads are assigned to the model. The TrueGrid® user can then select to format the model data for most of the popular three-dimensional simulation codes.
Graphical User Interface
TrueGrid® features a modern graphical user interface (114 Kb) that allows development of the mesh by "point and click". Graphics takes full advantage of color, producing vibrantly colored pictures of the geometry and the mesh. All of the meshes and grids in this web site were produced by TrueGrid®. Prompts, dialogue boxes, and an on-line help package intuitively guide the user in creating the mesh. Highly optimized and robust algorithms make it possible to build quality meshes interactively. Sophisticated three-dimensional graphics techniques allow the user to view the mesh as it is built.History
For over ten years major research laboratories have used an earlier version of this code, called INGRID, on supercomputers. XYZ Scientific Applications now offers a significantly improved version of this advanced technology to the entire engineering and scientific community.
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