Understanding the Stress Transformation Equations!

Question 2-48*: The stresses shown in the figure below acts at a point in a stressed body. Determine the normal and shear stresses at this point on the inclined plane a-b.
Please note: when we are rotating the axes of the coordinate system, we are simply visualizing the theta created, we are not actually manipulating the coordinate system or the stress element when this rotation occurs! Manipulating this would produce different stresses acting on the element!
If you have any recommendations for future problems, or have suggestion for tutorials in the future, feel free to leave a comment!

[@simple_civil]

If you wish to skip the theory, the problem begins at 6:10. Once again, thanks for watching and hope it helped

[@chichha420]

thanks

[@simple_civil]

No problem, thanks for watching !

[@williamskanthalo6242]

But I found shear stress to be -3MPa not 53 MPa. Can you please clarify on that

[@simple_civil]

I believe the first part of the equation, you end up with the wrong sign. -(-65-(-125))/2 sin (2 x 145) should give approximately a positive 28.2 and the 75cos (2 x 145) should give approximately 25.6. Hope that helps!

[@louis9137]

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