3.4 Working Planes
Although the cursor appears as a point on the screen, it actually represents a line through space, normal to the screen. In order to be able to pick a point with the cursor, it is necessary to define an imaginary plane that, when intersected by the normal line of the cursor, will yield a unique point in space. This imaginary plane is called a working plane (Fig. 3.6). Another way to consider the interaction between the cursor and the working plane is to picture the cursor as a point that moves around on the working plane. The working plane, then, acts as a ‘tablet’ on which the analyst writes with the cursor.
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Fig. 3.6 Relationships among Display Screen, Cursor, Working Plane, and Picked Point A working plane is an infinite plane with an origin, a 2-D coordinate system, a snap increment, and a display grid. Only one working plane can be defined at a time. Creating a new working plane eliminates the existing working plane. The working plane is separate from the coordinate systems; for example, the working plane can have a different point of origin and rotation than the active coordinate system. 3.4.1 Creating a Working Plane
By default, when the analyst initiates the ANSYS session, there is a working plane located on the global Cartesian X-Y plane, with its x and y axes colinear with the global Cartesian X and Y axes. 3.4.1.1 Defining a New Working Plane
A new working plane (Fig. 3.7) can be defined by using any of the following methods: 3.4.1.2 Controlling the Display and Style of the Working Plane
Use Utility Menu> List> Status> Working Plane to obtain the current status of the working plane. 3.4.1.3 Moving the Working Plane
A working plane can be moved to a new location using any of the following methods: 3.4.1.4 Rotating the Working Plane
The working plane can be rotated to a new orientation in two ways: by rotating the working plane's x-y coordinate system within the plane, or by rotating the entire plane to a new position. Use Utility Menu> WorkPlane> Offset WP by Increments to rotate the working plane. 3.4.2 Working Plane Enhancements
The working plane can be enhanced with a snap increment, a display grid, retrieval tolerance, and coordinate type using GUI path described earlier. Then, the coordinate system can be forced to follow the working plane as the working plane is moved using: All geometry is created with respect to the working plane, which by default is aligned with the global Cartesian coordinate system. The ‘Working Plane’ is actually the XY plane of the working coordinate system. The working coordinate system ID is coordinate system 4 in ANSYS. Global Cartesian is ID 0, Global Cylindrical is ID 1, and Global Spherical is ID 2.
Turn on the working plane using Utility Menu> WorkPlane> Display Working Plane. Change the way the working plane looks or adjust the snap settings under Utility Menu> WorkPlane> WP Settings…. Move the working plane around using Utility Menu> WorkPlane> Offset WP to…. Align the working plane with various parts of the model using Utility Menu> WorkPlane> Align WP with…. If more than one node or keypoint is selected to offset the working plane to, it will go to the average location of the selected entities. The working plane can be used to slice and dice the model. For example to cut an area in pieces use Main Menu> Modeling> Operate> Booleans> Divide> Area by WrkPlane.
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Fig. 3.7 Working Plane