Cross-Bracing Stiffness 1

[dik]

I'm modifying my spreadsheet for lateral load distributions and rather than use walls, I'm using cross-bracing. I'm looking for the stiffness of bracing for a movement in either the x or y direction.

I seem to recall it is of the form delta=P*x/(A*E*cos^2(alpha)

or

K=A*E*Cos^2/x

where A&E area and Young's modulus, x is the horizontal x-dimension, and alpha is the angle of the bracing to the horizontal. The squared value converts the P force to the diagonal force and the x dimension to the diagonal length. K is the stiffness. [post modified]

Can anyone confirm or provide a 'correct' formula?

Dik

 

[KootK]

This goody might get you where you need to go: Link

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[dik]

I'll take a gander... thanks

Dik

 

[dik]

Great Post with the relative components of the diagonal, the column and the girder.

My rough recollection is for the diagonal component of it. I'll take a look to see how it varies for all components; I suspect the girder and the columns will be minor.

Again, thanks very much.

Dik

 

[dik]

It's a good start... I'll use the components for column and diagonal since I don't have a girder. Thanks, gentlemen

https://files.engineering.com/getfile.aspx?folder=379e6a70-bb39-4be1-a5a3-b86489cce3be&file=XB.pdf

https://files.engineering.com/getfile.aspx?folder=86f3a658-31a1-44ec-9b28-e639fac250f8&file=XB.sm

Dik