How to Correct Circular Loading on a Hip Condition in MiTek

From time to time truss designers run into unique conditions in the MiTek software. Of course, software is only as effective as its user. One of the things we encounter at times is what is known as a “Circular Loading” condition.

Circular Loading is a situation where the loading applied keeps growing and growing. This is because the carried members touch each other. I still remember the first time it happened to me. I was a junior designer working in Alpine at Gator Lumber in Sebastian, FL. I could not understand why my load kept growing each time I went to specify a hanger! How naive I was then!

A common place to run into this issue is on a “California” Hip.

california-hip

This system is used to create more rigidity in a seismic region. But remember what I said above about a software and its user?

When you put this condition in MiTek Sapphire using the tool for this hip condition, it works beautifully. It is when we have a partial hip or a stubbed condition that we end up with problems. Here is the way to find and identify the problematic truss was:

Create trusses and review the error message:

mitek-error-message

Next, look at the trusses the error message pointed to. MiTek does an outstanding job recognizing these types of things and helping the designer identify them proactively. When you hit profile for the #1 hip setback girder, you will find something like this:

setback-hip

Once you identify the issue, look in visibility for the “Bearing” button:

visibility

Finally, select the little black diamond and change the properties window from active to inactive:

activity

You can now go to profile and see the truss again to verify that the issue has been resolved:

top-chord-extensions

You are now ready to re-send the truss to VersaTruss engineering…with no errors!

What other types of errors are you encountering when creating trusses? Comment below and give us an idea for another solution-focused article!

Christopher Gould – President

Gould Design, Inc.