Mechanical Engineering Streeses

[chrisking2021]

Mechanical Engineering Stresses

I am really struggling with the following problem:

A rectangular tube with no given length has the dimensions shown in the diagram (within the attachment). Find the maximum tensile and compressive stresses that such a section will experience due to a bending moment of 20KNm.

The attachment should be included if I've done it right.

I think i should be using "Second moments of area", but I'm not sure some clarification and possibly the formula would be gratefully received.

Thank you

Chris

 

[FredGarvin]

What's the definition (mathematical) of normal stress due to a bending moment?

 

[Jonny_trigonometry]

how is the bending moment applied? is the bar in torsion?

 

[sunday]

That tube works as a beam. From here, Google is your friend.

 

[Aero Stud]

http://en.wikipedia.org/wiki/Bending
http://en.wikipedia.org/wiki/Area_moment_of_inertia

 

[CPP]

think about the neutral axis and which side is in tension/compression then use the stress equation for a beam in symmetric (assuming) bending. simple. but I've done it a few times.