Elevation Load
Elevation distributed loads, which vary linearly between two points of different elevation along a boundary (i.e., the z-coordinate of each point differs) can be applied to edges or faces with the Add Load or Add Load to Selected options. The load distribution is treated as triangular (zero at one end) or trapezoidal (different non-zero values at each end) based on the user-specified Top Magnitude/Delta and the elevation of the boundaries.
Elevation loads can be applied by specifying Elevation Load as the Load Type in either of two ways:
- Define the projection shape by selecting Loading > Add Load
- Select faces, edges, or vertices of geometry, then select Loading > Add Load to Selected
Top Magnitude / Delta of Load
The Top Magnitude is the magnitude of the load that will be applied at the top or the highest point of the selected boundary (edge or face). The Delta Magnitude is the change in the load magnitude per unit decrease in elevation.
- Delta = 0 means that the magnitude of the load does not change with a decrease in elevation (z-coordinate). This type of Elevation Load is equivalent to a Uniform Load.
- Delta > 0 means that the magnitude of the load increases as the elevation of the boundary decreases (i.e. the load magnitude at the bottom of the boundary is greater than the Top Magnitude).
- Delta < 0 means that the magnitude of the load decreases as the elevation of the boundary decreases (i.e. the load magnitude at the bottom of the boundary is less than the Top Magnitude).
Load Magnitude
A distributed load magnitude is generally entered as a positive value. The direction of the load application is specified by selecting an appropriate Orientation method (see below) in the Add Load dialog. If a negative load magnitude is entered, the direction of the applied load will be reversed.
If Delta < 0 and the absolute value of Delta multiplied by the change in elevation is greater than the Top Magnitude (i.e., |Delta * change in elevation| > Top Magnitude), then the load at the bottom of the boundary will be in the reverse direction to the load at the top of the boundary.
Load Orientation
For details about defining the load Orientation, see the Uniform Load topic, as the same information applies to both Uniform and Elevation loads.