The legacy behavior of applied loads in Simulation Mechanical 2015 and earlier versions is that the specified load magnitude is applied to each selected entity (vertices, edges, or surfaces). For example, if you apply a 10 N force to three vertices or three surfaces, a total force of 30 N is applied (10 N per selected entity x 3 vertices or 3 surfaces).
In the Simulation Mechanical 2015 Product Enhancements release, you can now choose to distribute a surface force over a set of selected surfaces. The model must be CAD-based. Apply a distributed surface force as follows:
- Select two or more surfaces. The selected surfaces can belong to more than one part.
- Click Setup
Loads Force. Note: Alternatively, you can select the surfaces after clicking the Force command (swap the order of steps 1 and 2). - Activate the Distribute magnitude across all surfaces checkbox. Note: This option is only available when applicable. The following qualifications must be met:
- Geometry must be CAD-based
- Two or more surfaces must be currently selected
- Specify the desired magnitude and direction of the total force, and click OK.
The specified magnitude is distributed on a pro rata basis depending upon the area of each selected surface. The example in the following table explains how the load is distributed:
Example: Assume that a total force of 2,500 N is distributed over three surfaces (a, b, and c) with areas of 100, 300, and 600 mm2, respectively.
| Surface | Area (mm2) | Force (N) |
|---|---|---|
| a | 100 | 250 (= 100/1,000 * 2,500) |
| b | 300 | 750 (= 300/1,000 * 2,500) |
| c | 600 | 1,500 (= 600/1,000 * 2,500) |
| Total Area = 1,000 | Total Force = 2,500 |
- by moving vertices and therefore stretching surface lines, or
- by changing the surface number of the lines, thereby increasing or decreasing the size of the surface
then, the calculated surface forces may not be accurate.