# Elasticity problem

by physicist10
Tags: elasticity
 P: 17 Hello, I am struggling with this problem. It is probably the easiest problem ever... What I did: The plane has 2 stress components. σn and σs. σn is a multiple of (l, m, k) vector. For σs, I made up a vector (a, b, c) which is orthogonal to (l, m, k). And I equated all vectors. I'm probably doing something wrong. Any help is appreciated!
 P: 17 1. The problem statement, all variables and given/known data 2. Relevant equations General plane formulas. 3. The attempt at a solution I thought that the plane has 2 stress components. σn and σs. σn is a multiple of (l, m, k) vector. For σs, I made up a vector (a, b, c) which is orthogonal to (l, m, k). And I equated all vectors. I'm probably doing something wrong. Any help is appreciated!
 P: 10 Hello, I am not an expert on elasticity but this really looks quite straightforward. Let's first find the stress vector T (I'm using T instead of σ to avoid confusion with the stress tensor). You will get it by multiplying the (diagonal) stress tensor by your normal vector as T=(σ1l, σ2m, σ3n). It has two components as you wrote, Tn and Ts. The magnitude of Tn is simply the dot product of T and n and its direction is along n as you wrote. Vector Ts has to be the complement to the total stress vector. And for the second part - the shear stress will be maximum if vector T lies in your plane, e.g. the dot product of T and n is zero.
P: 5,462

## Elasticity problem

 zirkus Let's first find the stress vector T
Whilst this thread properly belongs in the homework section, this needs comment.

What is a stress vector?
P: 17
 Quote by Studiot Whilst this thread properly belongs in the homework section, this needs comment. What is a stress vector?
Aha, he's probably talking about the traction vector.

However, this was very helpful. Thanks
P: 10
 What is a stress vector?
We defined it similarly like the article on wiki does, so I won't rewrite it...Stress on Wikipedia
Most likely there are other methods or other terminology, I'm not a native speaker so i can't tell the subtle differences that well, sorry about that.
P: 17
 Quote by Zirkus We defined it similarly like the article on wiki does, so I won't rewrite it...Stress on Wikipedia Most likely there are other methods or other terminology, I'm not a native speaker so i can't tell the subtle differences that well, sorry about that.
Thanks Zirkus!

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