VisualAnalysis Tutorials: Extending Members
This example will display the use of the "Snap-To" and "Extend" features in drawing the truss shown below.
Modeling the Structure
We will first draw the left half of the truss:
7 Begin by drawing a right-triangle that is 20 ft long and 10 ft tall.
7 Under the Grid Tab of the Project Manager, click to make the Default Grid not visible.
With the grid now turned off, you are now able to "Snap-To" to existing members.
Sketch the member starting at the top of the truss, moving downward to the bottom member's first quarter point, at 15'.
Using the beginning image, sketch the remaining members of the truss section. Your model should now look like the picture below. (Sometimes it is easier to split members into the desired number of pieces. Also, you can always move you node after it is created in case it's not exactly where you want it.
Select the top and bottom chords of the truss and select Model | Split Combined Member.
Now the unwanted members and nodes of our truss half can be deleted.
We will now use the Generate copies feature to draw the other half of the truss. [Editor's note: VisualAnalysis has added a mirror-copy feature since this tutorial was written!]
Hold down the Shift key and click on one of the truss chords to select all of the members.
Click Model | Generate Copies and select to use a mirror copy.
Select Global X for the Normal Direction, and specify Thru-Point 1 as X= 20'.
The model should now appear as shown in the image below.
To finish our model, we will now use the member extend feature.
Select the top-left member to be extended and go to Model | Extend Members.
Members are extended according to how they were drawn in Model View. They can be extended forward or backward by either a prescribed amount or until they encounter another member.
Choose the appropriate direction and extend the member by 10 ft. Click OK.
Select the vertical member to be extended and go to Model | Extend Members.
Choose the appropriate direction, leave the "Extended By" input box to 10ft, and make sure the "Stop at First Intersection" option is turned on. Click OK.
The unwanted section of the truss can now be split up into individual member and deleted. Boundary conditions, truss loadings, and material type and shape are now ready to be set.