SHS / RHS Section Modulus Approximation 2

[Martin.H]

I recently saw in a UK design guide some formulas for simple hand calc approximation of SHS or RHS section properties allowing for the corner radii (Second Moment of Area, or Section Modulus, I forget which).

I can't for the life of me remember where I saw it, but now I need it! Can anyone point me in the right direction?

Martin.

 

[desertfox]

Hi

Not got the formula to hand but I managed to find some tables

https://roymech.org/Useful_Tables/Sections/RHS_cf.html

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Martin.H]

Thanks @desertfox, but I'm looking to create a spreadsheet where SHS or RHS sections can be described by entering by overall dimensions and wall thickness.

Martin.

 

[robyengIT]

it's in french, bur free software, for any section, even designed by yourself

https://www.cticm.com/logiciel/propsection/

 

[Martin.H]

Thanks robyengIT, but the end goal isn't the member properties. I'm making a spreadsheet for checking hollow section welded joints using the formulas in BS EB 1993-1-8.

I could import a table of section properties from online 'Blue Book' (an excellent resource) and vlookup the data in Excel that way to extract what I need, but I'm hoping for a more generic solution using the formula's I know I've seen somewhere!

Martin.

 

[patswfc]

Martin, equations for sections properties can be found in this link https://eurocodeapplied.com/design/en1993/shs-design-properties

 

[Martin.H]

Thanks patswfc.

Martin.

 

[Celt83]

Since your trying to make a spreadsheet look into the "shoe lace" theorem which is an application of Green's Theorem: Link

also reference the "any polygon" section of this wikipedia page: Link
(this is also an application of Green's Theorem)

For an RHS shape you can approximate the corner radii with a few straight segments depending on how accurate you want to be. Model the outerwall with coordinates defined counter-clockwise and model the inner wall with coordinates defined clockwise and then add the resulting centroidal section properties.

User IDS has this spreadsheet: Link
User Handofthelion has created this python program: Link
I have created this spreadsheet: Link

My Personal Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

Open Source Structural GitHub Group:

https://github.com/open-struct-engineer