Torsional checking for Steel angle member

[wkh023002]

Homework Statement

I meet a problem below:

To check if the angle :200x150x12 S275 Grade can take a twist of 30kNm (on plan ) with Span 3m fixed end connected.

Homework Equations

θ = T L / J G

The Attempt at a Solution

My question is that even I got the angle of twist for this member??
how can i check against design twist (30kNm) to see if it is adequate ?

 

[PhanthomJay]

Well this case should generally be avoided because angle sections are not very good in torsion. What you are looking for is the max shear stress in the member, Tc/J, where T is the twisting moment, c is the angle thickness, and J is the polar moment of inertia often calculated by summing the values of 'bt^3/3' for each leg, where b is the appropriate leg width. Then compare that stress to the allowable shear stress of the material. Note that the steel angle section will both twist and warp. I haven't done such a calculation since school days.