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Unistrut code evaluation report

Unistrut code evaluation report

Unistrut code evaluation report

(OP)
Hi all. This question is a result of days of looking through Unistrut's extremely poor engineering literature. I am scavenging for a code evaluation report for either Unistrut or a similar product (such as Powerstrut) to help me navigate this stuff. Anything remotely close to a code evaluation report for these products? I searched on ICC but found absolutely nothing.

RE: Unistrut code evaluation report

Why does it matter? We use those things all the time without any questioning by building officials, etc.

That said, I am guessing you are looking for some more load capacities for a connection that isn't tabulated in their book? That has happened to me before, and I emailed Unistrut and asked them to provide me the capacity for the configuration I wanted. Thus far, I have had no problems getting the info I needed.

"It is imperative Cunth doesn't get his hands on those codes."

RE: Unistrut code evaluation report

(OP)
The reason is to get a better idea of where the numbers in these product catalogs come from and to produce more versatile designs.

RE: Unistrut code evaluation report

Unistrut does not have any ICC reports

They do provide section properties so you can run calcs as needed

RE: Unistrut code evaluation report

(OP)
Run calcs based on what?

RE: Unistrut code evaluation report

Based on the section and material properties? I am confused at what really is the end goal.



"It is imperative Cunth doesn't get his hands on those codes."

RE: Unistrut code evaluation report

(OP)
The end goal is to calculate the shear, flexural and axial capacities for various unistrut components and attachments. With section/material properties I can determine axial, shear and flexural demands (and deflections) ... not the capacities...

RE: Unistrut code evaluation report

If you have section and material properties you should be able to calculate the capacities. Demand is driven by the applied loading, capacity is given by the section and material properties.

RE: Unistrut code evaluation report

Quote (awa5114)

With section/material properties I can determine axial, shear and flexural demands (and deflections) ... not the capacities...
Get yourself a copy of "CFS 9.0" (RSG Software) and run it as a special section. Otherwise, calc it by hand using the ridiculously complex AISI LGS Design Manual.
I think Hilti also has load tables for their components.

RE: Unistrut code evaluation report

It sounds like you are trying to reinvent the wheel a bit, and in a risky direction, unless I am reading this incorrectly. Maybe you are just trying to get a feel that their tabulated capacities make sense to you so that you are more confident when specifying their components?

Unistrut engineers their lightgage products to generally conform with the AISI steel code, but their wacky proprietary perforated shapes fall outside of using the AISI to directly calculate their capacities. Hence, they load test their unique products, and provide their section capacities in the general engineering catalog. I am certain you could use the AISI code to calculate the capacities of common shapes, but why? I don't see how that is going to produce more efficient designs. Besides, if your computation resulted in an allowable bending moment 20% higher than the tabulated capacity, why would you want to stick your neck out and use the higher capacity?

Am I still missing something?

"It is imperative Cunth doesn't get his hands on those codes."

RE: Unistrut code evaluation report

XR250, you have to be careful with accidentally bypassing Unistrut's empirical testing.

"It is imperative Cunth doesn't get his hands on those codes."

RE: Unistrut code evaluation report

Unistrut actually gives capacities for beams and columns. I do not see any combined loading however in which case I assume you would have to use some software and give some cushion.
I also imagine the holes are not a huge issue as the open side likely controls much of the design.

RE: Unistrut code evaluation report

Quote (XR)

I do not see any combined loading however in which case I assume you would have to use some software and give some cushion

I wouldn't go there unless I *had* to, and even then I wouldn't want to. I haven't had a crazy beam-column Unisrut yet. To me, it is much quicker and conservative to use an elliptical interaction equation with the power coefficients set to 1.0.

Awa, can you give us a sketch and loading of the frame you are designing?

"It is imperative Cunth doesn't get his hands on those codes."

RE: Unistrut code evaluation report

Quote (MACGRUBER22)

I wouldn't go there unless I *had* to, and even then I wouldn't want to. I haven't had a crazy beam-column Unisrut yet. To me, it is much quicker and conservative to use an elliptical interaction equation with the power coefficients set to 1.0.

I totally agree. Serviceability would probably control some of it anyway.

RE: Unistrut code evaluation report

I am very curious as to the loads and framing awa is dealing. Patience...Patience.....

"It is imperative Cunth doesn't get his hands on those codes."

RE: Unistrut code evaluation report

(OP)
Hey MacGruber22...

My situation is that I am trying to make sense of the Unistrut general engineering catalog so that I can spec bracing systems for mechanical equipment. Not a specific framing/loading situation. As a recent grad, I have no idea how to use these catalogs. There is no guidance for new users, and the only resource I found is the following (http://www.unistrut.us/E-document/Unistrut-Seismic...) with a couple of (really) crappy low quality examples. I just need something that can help me use the general engineering catalog... a sort of comprehensive "user manual" geared towards new users with structural engineering background. I know it sounds like I am trying to reinvent the wheel, and maybe I am a little bit, but I believe SOME background is helpful, if not necessary, to pull values from these tables! Anyone can pull values out of the air but an engineer is supposed to know what theyre doing at least a little bit...

RE: Unistrut code evaluation report

Quote (awa)

Anyone can pull values out of the air but an engineer is supposed to know what theyre doing

Absolutely. Proper interpretation of those tables requires comprehensive engineering expertise. Also, the nature of tables is that their use implies that there are restrictions for how/where they are appropriate.

Quote (awa)

As a recent grad, I have no idea how to use these catalogs

I completely understand. What about guidance from your supervising PE? It can be tough to guide very broad questions via an internet forum, but as XR250 mentioned, you should start getting comfortable with lightgage design per the AISI code. Most of Unistrut's components fall under light gage steel. Though, some of the plate material technically falls under structural steel.

Quote (awa)

so that I can spec bracing systems for mechanical equipment. Not a specific framing/loading situation.

You are writing a spec? I am surprised that as a recent grad that you are doing that, assuming that your position is that of an entry-level structural design engineer. Maybe your position is actually as a spec writer? That would make sense. Or - do you mean that you are just trying to prepare yourself for when you do have to design some bracing? I am curious what spawned that.

I ask those questions to try to maybe narrow down enough to provide some more specific guidance.

"It is imperative Cunth doesn't get his hands on those codes."

RE: Unistrut code evaluation report

(OP)
Hey MacGruber,

Many thanks for the advice and interest. I will follow your recommendations very closely. No, not a spec writer, I'm just preparing myself for when I'm asked to design this type of bracing....

RE: Unistrut code evaluation report

Good luck

"It is imperative Cunth doesn't get his hands on those codes."

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