While learning about normal and tangential stress, we had a task, where I had to calculate the cross sectional area of a beam that could withstand the force applied to it, if the beam was sliced in the middle on an angle (Like two 90 deg trapezoids glued together).
I hope this makes sense.. having a language barrier here.
I was given the maximum allowed normal and tangential stresses under which it would not break.
As we know, Maximum tangential stress = 0.5 maximum normal stress.
I was given two values. For example, the max normal stress was 7.6 MPa and the tangential stress was 4.1 MPa and according to the rule, if tangential stress is 4.1 then the max normal stress can be 8.2 MPa. So the calculations are done based on the lowest value, since it can't hold any higher...
But if I'm only basing on one of the values and they're both connected to the equation, why does the task give me both? Is it just for the task, or in real life there are there materials that somehow have specifications for the tangential stress and normal stress boarder values which are different when using the equation?
I hope any of this makes sense.
The question basically is- How can the same material have two different values of stress it can withstand? Is it just for the task or..?