CHS Web Bearing

[EddleM]

I am trying to design CHS columns that are taking lateral compression loads from struts. The struts are connected to the CHS columns via a cleat welded to the side of the column.

I'm trying to find any design guides that give guidance on calculating localised yield failures of the CHS web due to bearing stresses but with limited success. I am designing to AS4100 and am currently looking at using some of the assumptions used for bearing stress transmittal from flange to web, but i'd rather see a proper method if there is one.

Thanks,

 

[msquared48]

I am unfamiliar with the term "CHS".

As you are down under, is this perchance a High Strength Channel section?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[hokie66]

No, it is a circular hollow section. Otherwise known as a pipe column.

 

[msquared48]

O

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[hokie66]

Eddie,
The Cidect Design Guides are very helpful, albeit European. I don't know about guides specific to AS4100. Smorgon Steel's manual for hollow sections has a Part 9 for connections, but my old copy has that section essentially blank. It does refer to a 1996 publication by Syam and Chapman "Design of Structural Steel Hollow Section Connections-Volume 1: Design Models". Suggest you call the ASI direct.

 

[EddleM]

Thanks i'll investigate.

I've looked through BS and Eurocodes but theres no real guidance.

The closest i've got yet is the distribution of stress from the flange of an SHS to its web, i think its fair to approximate a stress distribution from the cleat to the neutral axis of the wall of 1 to 2.5, but i'm not sure what limiting values to take for local yielding stress in the CHS, especially taking into account the existing stresses due to axial load and moments...

Thanks,

 

[msquared48]

OK... I'll bite... What's SHS?

Where I am it's an abbreviation for Snohomish High School.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[weab]

M48,

Often, I deal in Australian sections. From this I assume:

CHS-Circular hollow section (pipe)
SHS-Square hollow section (square tube)
RHS-Rectangular hollow section

 

[BAretired]

Do not use abbreviations unless you are quite certain that the people reading your thread understand what you are talking about. If you want guidance from this or any other forum, state your case clearly without abbreviations. Then, and only then, we may be able to offer some guidance.



BA

 

[Stillerz]

EddleM-
Just some thoughts here ....
I don't know your exact situation but there were a few occasion's I had to deal with a similar thing.

On the connection tab at the pipe (or in my case, huge fabricated box columns) I actually knifed the cleat or tab all the way through the pipe...actually slotted the box column and ran the tab all the way thru the column and out the other side.
The transfer forces thru the column were thereby minimized.

Of course, if there are beams connecting only to one side of your "CHS" this wont be as much help.

 

[apsix]

The OP could be quite certain that engineers from OZ/UK/NZ would know what the question is about.

EddleM, try the attached.

 

[hokie66]

Eddie,

You might have avoided a bit of grief by posting in the specific AS/NZ forum. Most of us in Oz monitor that one.

Just a word of caution. The reference apsix gave does not consider recent advice about design of unstiffened eccentric cleat plate connections in compression. The eccentricity of the plates cannot be ignored.

 

[matejic50]

Thanks

 

[EddleM]

Hokie66 - Thats exactly what i'm looking for thanks.

And yeah slotting through solves the problem, but its not possible for me to do everywhere.

Thanks for the help.