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Stress/Displacement Calculation: Introduction
Examine3D enables users to view stress / displacement calculation on user specified planes and points, within volumetric grids, and on surface excavation.
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Stress/Displacement Calculation: User Specified Plane
The visualization of stress tensor data has historically taken the form of displaying one of the scalar components of the stress tensor, principal stresses, or maximum shear stress by contouring discrete data on a user-defined cutting plane. The figure below is an example of this type of technique.
Display of the major principal stress (Mpa) of an underground power cavern via user specified cutting planes
This method provides a great deal of information about the distribution of stress locally to the cutting plane and is very easy to interpret. The ease with which the user can understand the data is the major reason for using this type of graphical display of data.
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Stress/Displacement Calculation: User Specified Point
This method is similar to that of user specified plane (above). The difference is that users are now defining points and not planes.
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Stress/Displacement Calculation: Volumetric Grid
Viewing data through a volumetric grid allows for the visualization of the global stress state (as oppose to a 2-D cutting plane). Two methods are available: the first method, which is an extension of the two-dimensional cutting plane, works by passing a two-dimensional contoured cutting plane, in real-time, through the grid. As the cutting plane proceeds through the grid, the stress contours are updated on the plane (see figure below). The direction in which the plane passes can be changed giving a three-dimension perspective on how the stress state varies. One advantage of this technique is that most engineers have experience interpreting data on two-dimensional planes and, as a consequence, have little trouble in understanding the results using this method.
Display of the major principal stress (Mpa) of an underground power cavern via cutting planes within a volumetric grid
The second method for volume visualization of stress data uses the marching cubes algorithm to generate isosurfaces of stress.
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Stress/Displacement Calculation: Surface Excavation
The surface contours function plots values of stress at every node on the excavation surface. This allows the user to establish the state of stress right at the excavation/rock mass interface for the purpose of estimating instability.
Surface major principal stress (Mpa) contours
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