Optimize Tray Ceiling Truss Designs

Video Transcript:

In this next video, we are going to review the tray ceiling truss from Training Plan 3 to address design checks that have been exceeded.

We will start by selecting A01A to review the component in Design mode.

We see quite a bit of red in the scene which we'll systematically address. In the bottom left, we see a plating error message. Clicking on the error will open the notification center which will display all errors for the active component. Here it shows plate pair 15 B overlaps, plate pair 15 A.

Additionally, three members are displayed in red, indicating the members are over capacity. Hover over each red member to see additional information, which will help us better understand the problem so we can devise a solution.

Focusing on T1, the 2x4 is over-stressed. Let's change this to a 2x6 to see if that helps.

Right click on T1, select Edit Lumber and change from 2x4 to 2x6.

Next, let's select T1, and we will trim that back to the top edge of B1. And, then we will trim T1 back to the left edge of the bearing.

Then we will select B1. Then go over to the member properties panel and we will review the Left Cuts. Here, we will delete the T1 starboard cut from the list.

Next we will re-analyze this truss to see if that helped.

Looks like we have another error to look over. It appears T1 overlaps B2. So, let's clean that up. Select B 2 and then we will trim that back by shift clicking on T1.

For this example, we'll strengthen this joint by having B2 connect directly with T1.

To do this, let's trim back EV1. Select EV1 and then press Shift and select the bottom edge of B2.

Next, trim B2. Select B2, and from the properties panel, review the Left Cuts. We will select PB2 Parallel, so to edit this cut, and then we will select the left edge of EV1.

That'll do it. Let's re-analyze this once more. We want to see what our adjustments have done for us here so far.

Our chords are still overstressed. Hovering over B2, we see that it is over capacity, so let's change this to a 2x6. Right click, Edit Lumber and change dimension to 2x6.

Let's run a detailed analysis. Click the gear icon to access Analysis Options and select Detailed. Then let's re-Analyze the truss to see how we're doing..

This now looks like our lumber all passes checks, but we can see that there are still failing checks.

From the top, we will click to open the Analysis and History option. Then along the left side towards the bottom of the panel, we see that Plates are over capacity. Expand plates and see that Plate Pair 3 needs some attention to improve grip on B2.

So, let's adjust the plating. We can move the plates around by clicking and dragging the arrow in the desired direction. Alternatively, individual clicks on a specific arrow, will move it in small increments. Use both methods to fine tune the plate placement.

We can also rotate the plate. As we adjust the plate, the red coloration indicates the single plate pair will not work for this joint.

Let's choose a new plate size. Right click, select edit properties, and then change the dimensions of the plate to a 3x8. We chose 3x8 here, because that's the same size plate as the one directly below this joint.

Left click and drag on the arrows to move the plate and rotate as needed to place the plate above the existing 3x8 plate on the EV1 member. The plate will display red which is OK for now because we'll be adding an additional plate pair.

So, to add a plate, let's right click and select plate pair. Here, we will add another 3x8 plate from our selection. Click to place it in the area where T 1 and B 2 come together. Once it is placed, we can adjust as needed using the arrows and the rotate options.

Fine tune the newly added plate pairs until both plates are under 100%.

Remember, when you manually add or modify plate pairs, those pairs will be locked.

Let's click to re-analyze this truss after we've added our plate. It's important to acknowledge that our new plate pair is at 96% capacity. In reality, you may want to upsize plate pairs to be more conservative. This all looks good.

We hope this video has provided you with practical examples and tools for overcoming design checks that have been exceeded.

Thanks for watching!