Add a Truss Area and Truss Volumes

You can use this function to define a general truss area, and add truss volumes to it with even intervals. In order to define the shape of the truss volumes, select the upper and lower structures limiting them, for example the roof slopes and the ceiling.

You can change the order of selecting structures with a keyword in the user/SETUP file. See Input Order of Structures when Adding a Truss Area.

1. Do either of the following:
   • Select Modeling | Panel | Truss Standard Trusses Trusses.
   • Right-click to open the context-sensitive menu, and select Trusses.
2. Select the truss parameters.

   Truss Parameters

3. Select the upper limiting structures. Select several slopes by holding down the Ctrl key, or use an area selection.
4. If necessary, select a function from the auxiliary menu to determine the distance between the top chord of the truss and the limiting structure:
   • Editing Slope Reference Data
5. If necessary, edit the truss area by adding or removing sections of roof slopes. You can select following functions from the auxiliary menu:
   • Add a Slope Extension
   • Set Slope Shape
   • Cut Slope Shape
   • Define a Limiting Plane
   • Delete Slope Shape
   • Edit Slope Shapes
6. Select Confirm.
7. Define the bottom chord of the trusses. Do one of the following:
   • Select the lower limiting structures, for example the ceiling. If the structures are added in drawing-model pairs of their own, select the structures in the 3D model. If necessary, you can hide the geometry of the roof from the model to make it easier to select the ceiling, see Selecting a Roof/Ceiling. If necessary, select a function from the auxiliary menu to determine the distance between the bottom chord of the truss and the limiting structure:

     Editing Slope Reference Data

   • Enter the support height and select the points of the limiting area. Select the following function from the auxiliary menu:

     Define a Limiting Plane

   • Select the definition according to the exterior surface of the bearing walls. You will select the walls as the last step of defining a truss area. Select the following function from the auxiliary menu:

     Bottom of Trusses by Bearing Walls

   • Select directly the Confirm function. The bottom chord of the trusses will be determined by the roof volume in the model.
8. Select Confirm.
9. From the auxiliary menu, select the location method, which will determine the point from which the positioning of the trusses will be started.
   • From left
   • From right
   • From both ends
   • From selected point
   • Center point of the interval in the selected point
   • Fit gable truss
   • Evenly spaced

   Truss Locations in a Truss Area

10. If necessary, select the truss adjustment for the first and/or last truss. When you select the adjustment, the truss edge will be positioned in the selected truss line point.
    • Adjusting the First Truss
    • Adjusting the Last Truss

    Fitting the Truss

11. Click the truss line points, or the first and last truss position. The centers of the trusses are positioned in the selected points, unless you have selected the truss adjustment for the gable trusses. Please note, that the trusses are created perpendicularly to the line between the selected points.
12. Select the bearing structures (walls and beams). You can edit the selection by clicking a selected structure to remove the selection.

    If you selected the function Bottom of Trusses by Bearing Walls when defining the lower limitation of the truss area, the bottom chord of the trusses is determined by the exterior surfaces of the bearing walls you will select.

13. Select Confirm.