Torsion section properties - Channels

• Oct 24, 2020

• #2

Mohanlal0488

Structural

Jun 26, 2020

103

I think I have seen such information in documentation from the BCSA, it was in collaboration with TATA steel.

I have the document at work, will send the details on Monday, if it has the information you are looking for.

 

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• Oct 24, 2020

• #3

r13

Civil/Environmental

Oct 26, 2019

5,988

"Wno" denotes normalized warping function, used in AISC Design Guide 9, as well as the warping statical moment Sw1, Sw2, Sw3.

 

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• Oct 24, 2020

• Thread starter
• #4

LR11

Structural

Sep 13, 2001

166

OK thanks you're right there were some formulas in there for channels.
I was checking for a 430x100PFC and have come close to matching the values in a Table from an SCI publication.
Except for Sw3 where I am way off.
I come up with 258cm3 for a section with no root fillets, compared to the tabulated 491cm3. About 50% off.

 

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• Oct 27, 2020

• Thread starter
• #5

LR11

Structural

Sep 13, 2001

166

Could there be an error in the formula?

 

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• Oct 27, 2020

• #6

r13

Civil/Environmental

Oct 26, 2019

5,988

Could be. I can't get the S_w3 number list in the table either, assuming S_w2 and W_n2 are correct.

 

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• Oct 27, 2020

• Thread starter
• #7

LR11

Structural

Sep 13, 2001

166

OK thanks for checking.
With the channel shapes in the AISC reference, it appears that Sw3 is about half of Sw2, whereas in the SCI reference Sw3 and Sw2 are about the same.
Perhaps the SCI reference is incorrect.

 

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• Oct 28, 2020

• #8

jimstructures

Structural

May 6, 2009

389

Have you looked on the AISC web site for an errata for the Design Guide 9?

Be very careful of judging the value of Sw3 from the sketch of the cross section of the channel, relative to the value of Sw1, as the sketches may only an artist's representation of the relative values and may not be geometrically correct in absolute value.

Jim

 

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• Oct 28, 2020

• Thread starter
• #9

LR11

Structural

Sep 13, 2001

166

Yes I have seen the Errata List.
There is nothing in terms of the tabulated section properties.
The formula seems to agree with the tabulated properties in AISC (for a C15x50). But not for the 430x100 channel in SCI. This was for the property "Sw3".

 

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