Create Girder and Jack Roof Truss Connections

Video Transcript:

Welcome! In this video we will go over the tools available when working with Girders and Jacks.

As you can see we’ve have a pretty standard girder truss, but we need to design a jack and correctly connect it to the girder. Let’s start by designing an open jack.

Open the component creation subpanel and use the profile line tools to input our dimensions. The length of this jack is 6 feet with a 4/12 pitch.

We can close the profile and move on to the shape details.

The plans we are working from note that it has a 1 foot overhang, so we will update this and change the right overhang to 0. If you keep the overhang at 1 foot, the truss will extend beyond the needed dimension of 6 feet. So, make sure you set the right side overhang to 0.

Navigate to the bottom of this panel and make sure Jack, and Open are selected and the carried side is set to Right.

Click next to move on to the structural details.

We need to update the right side bearings. Delete Bearing 2. And click Add Bearing. We can add a bearing on the top chord. Then add one to the bottom chord. Since this is an open jack, Paragon defaults these to Toe Nail. This is what we need so we will click insert.

Great, now that we have this jack inserted we need to analyze it and connect it to the girder. Once the jack is analyzed and all checks pass, we can go back to the girder and navigate to Carried Components in the Collections Subpanel. Use the menu button to open the create carried components subpanel. Here we can select our jack and specify which bearing on the jack we want to use. Let’s start with the bottom right bearing. Since we picked the bottom bearing, we need to make sure Bottom Chord is selected for Carrying Member Type. Next, we will use the X location input to specify exactly where we want to place this connection on the bottom chord. We are going to place this jack connection at 6 feet. You can use the Number of Carried Components and Distance Between Repeated Carried Components inputs to insert multiple connections, but for this example we will focus on one for now. Click insert to finalize this connection.

We need to add another connection for this jack at the top chord so open the Carried Components subpanel again and repeat the previous steps. This time, we will make sure to select the top right bearing and specify the Top Chord as the Carrying Member Type. And set the X location to 6 feet once again. Click insert to finalize the connections for the jack and analyze the girder. Once the analysis finished you can see the connection points on the truss in the scene.

Next we will create a closed jack. We could create another truss from scratch, but for this video we’re going to convert the jack we just made.

Select our jack and click Convert to Settings in the Edit Truss menu. A screen message will appear asking, Are you sure you want to go back to the original design settings? Click OK to accept.

Navigate to the Jack Settings section. Here we will click and deselect Open.

Click next to move on to the structural details.

We are going to delete both of the two right bearings. So, click a bearing then delete it from within the bearings box.

Repeat this process for the other bearing for the same end.

Next we need to add a new bearing under the right end of B1.

Click insert. And then we will change this bearing from a double plate to a hanger. Click on the bearing, then in the bearing type pull down, select Hanger from the selection.

Now that we’ve converted this open jack to closed, we need to analyze it and connect it to the girder.

This process is similar to the open jack but we will only need to specify one connection at the bottom chord for the hanger to be attached to the girder. Click on the girder truss to activate it.

Next, click to create a carried component.

We will set the carrying member type to bottom chord.

Select the bottom end of the truss as the Bearing on Carried Component.

Connect this jack at 14 feet.

Then insert the connection.

Note that the top and bottom chord connections from the Open Jack are still present.

To remove a manually defined connection, select the specific Carried Component connection and press Delete on your keyboard.

Repeat for the other connection.

Next Analyze the girder, and you’re done!

Thanks for watching this video on Jacks and Girders and we’ll see you in the next one.