Simultaneous Shear And Tension on threaded rod 1

You need to account for shear/tension interaction. For bolts, see AISC spec section J. For threaded rods, the unity equation you gave is conservative.

Assuming the stresses are below yield, the interaction formula is:

(&[ignore]sigma[/ignore];/&[ignore]sigma[/ignore];[sub]y[/sub]) + (&[ignore]tau[/ignore];/&[ignore]tau[/ignore];[sub]y[/sub]) &[ignore]le[/ignore]; 1

where

&[ignore]sigma[/ignore]; = applied tensile stress
&[ignore]sigma[/ignore];[sub]y[/sub] = tensile yield stress
&[ignore]tau[/ignore]; = applied shear stress
&[ignore]tau[/ignore];[sub]y[/sub] = shear yield stress




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I erred in my previous post - each ratio should be squared:

(&[ignore]sigma[/ignore];/&[ignore]sigma[/ignore];[sub]y[/sub])[sup]2[/sup] + (&[ignore]tau[/ignore];/&[ignore]tau[/ignore];[sub]y[/sub])[sup]2[/sup] &[ignore]le[/ignore]; 1

where

&[ignore]sigma[/ignore]; = applied tensile stress
&[ignore]sigma[/ignore];[sub]y[/sub] = tensile yield stress
&[ignore]tau[/ignore]; = applied shear stress
&[ignore]tau[/ignore];[sub]y[/sub] = shear yield stress

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

Thanks CoryPad,
Can you give a reference on that formula?

Handbook of Bolts and Bolted Joints, edited by Bickford and Nassar, page 408. More generically, it can be derived using the von Mises/distortion energy yield criterion.





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Thanks. I appreciate your help.