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You can model solids of revolution using the SimMechanics™ Revolution shape. Examples of solids of revolution include cone and circular dome shapes. In this example, you model a simple solid with cone shape using the Revolution shape. For an example that shows you how to model a circular dome solid, see Model Dome.
To represent the cone geometry, first identify its cross-section shape. This is the 2-D area that SimMechanics revolves to obtain the 3-D cone. Then, specify the cross-section coordinates in the Solid block dialog box. These coordinates, must satisfy certain restrictions. See Cross-Section Coordinates.
The cone in this example has a trapezoidal cross-section. The figure shows this cross-section.
The [0 0] cross-section coordinate identifies the reference frame origin for this solid. To place the solid reference frame at the cone tip, you by specify the coordinates so that the [0 0] coordinate coincides with the tip. By parameterizing the cross-section coordinates in terms of the relevant cone dimensions, you can quickly change the cone dimensions without having to reenter the cross-section coordinates. The figure shows the parameterized cross-section coordinates points.
Add and connect the blocks to represent the cone. Include a Solver Configuration block so that you can visualize the solid in Mechanics Explorer during the modeling process.
Drag these blocks into a new model.
|Simscape™ Utilities||Solver Configuration||1|
Connect the blocks as shown.
In the Solid block dialog box, specify these parameters.
|Geometry > Shape||Select Revolution.|
|Geometry > Cross-Section||Enter CS. Select units of cm.|
|Graphic > Visual Properties > Color||Enter RGB|
Select the Solid block and generate a new subsystem, e.g., by pressing Ctrl+G.
In the subsystem mask, initialize the solid parameters. Then, in the subsystem dialog box, specify their values.
Select the Subsystem block and create a subsystem mask, e.g., by pressing Ctrl+M.
In the Parameters & Dialog tab of the Mask Editor, drag four edit boxes into the Parameters group and specify these parameters.
In the Initialization tab of the Mask Editor, enter the initialization code for the CS variable.
Alpha = atan(R/H); CS = [0 0; R H; R-T/cos(Alpha) H; 0 T/sin(Alpha)];
In the Subsystem block dialog box, specify these parameters
|Color||[0.85 0.45 0]|
You can now visualize the cone that you modeled. To do this, on the Simulink® menu bar, select Simulation > Update Diagram. Mechanics Explorer opens with a 3-D display of your model. Rotate, pan, and zoom to explore.
Try modifying the cone geometry. To do this, in the subsystem dialog box, change the dimension parameter values. Then, update the model. The figure shows some examples.