Combining stresses to compare with yield stress
Combining stresses to compare with yield stress
(OP)
Hello,
I am checking a steel beam element. How can I combine the maximum stresses due to bending and shear so that I can compare a single value with the yield strength of the material?
Is it wrong to combine them as the maximum bending stress is at the cross-section extremes and the maximum shear at the center of cross-section?
Thanks in advance :)
I am checking a steel beam element. How can I combine the maximum stresses due to bending and shear so that I can compare a single value with the yield strength of the material?
Is it wrong to combine them as the maximum bending stress is at the cross-section extremes and the maximum shear at the center of cross-section?
Thanks in advance :)






RE: Combining stresses to compare with yield stress
RE: Combining stresses to compare with yield stress
I do use combined stress by using square root of sum of squares for guard rail weld capacity check.
RE: Combining stresses to compare with yield stress
If you are checking some sort of localized stress situation, I think you should use the von Mises formula to combine stresses.
DaveAtkins
RE: Combining stresses to compare with yield stress
The design code that you use should have a check for shear and then a separate check for bending (including lateral torsional buckling, if applicable to the form of construction).
When you have high shear, this can effect the beams moment capacity and your code should probably have 2 different equations when checking out bending capacity, one for low shear and one for high shear (the later will give a lower bending capacity). The use of the correct equation depends on the magnitude of the shear load. This is the only interaction that i would think that you would need to account for.
RE: Combining stresses to compare with yield stress
Furthermore, for steel beams, the yield strength of the material may not fully define the capacity of the member.
If you can provide some additional detail for your application (beam section, span, supporting and bracing elements, etc), we can attempt to point you in the right direction. Otherwise, you need to consult an experienced structural engineer.
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The name is a long story -- just call me Lo.
RE: Combining stresses to compare with yield stress
Not sure which country you are from but this is actually a very basic question for an structural engineer
best regards
Klaus
RE: Combining stresses to compare with yield stress
I am a simulation engineer by education but want to make a career in structural design. Could you please recommend a book or some other source of education so that I can develop some basic skills in structural engineering?
Best regards,
Su
RE: Combining stresses to compare with yield stress
A typical time that you use "combined" stresses is for a check called a "unity" check. This is where stresses from two different sources, compared to their respective maximums in a ratio are added together or combined to see if those two ratios are less than a unit value of 1. In some codes and some applications, this is a mandated check.
RE: Combining stresses to compare with yield stress
I'd read a structural analysis book cover to cover, a mechanics of materials book cover to cover, and a steel design book cover to cover. Do you have a structural PE that can mentor you? A solid mentor is priceless.
RE: Combining stresses to compare with yield stress
I'll start with a structural analysis book for now - Structural and stress analysis by T.H.G. Megson.
I don't have a mentor. There are some colleagues who may help but this depends on their availability.
RE: Combining stresses to compare with yield stress
RE: Combining stresses to compare with yield stress
Does anyone know if there is a book which is similar to "Schneider - Bautabellen für Ingenieure" in English language?
RE: Combining stresses to compare with yield stress
best regards
Klaus
RE: Combining stresses to compare with yield stress