Given This Diagram, I am to:
Determine Principal Stresses
(My Ans: 92000 and -8500kPa confirmed with Answer Key)
Determine Max Shear
(My Ans: 50500 kPa confirmed with Answer Key)
Find the Angle between the plane of the maximum (positive) shear stress and the original plane of stress.
(My Ans 28deg Answer Key -61.8deg)
My Mohr's Circle has C=42,000 and R=50,477 It is my understanding that my original point would be at (84,000 , 28,000) and the max shear stress is at the highest Y value of the circle (42,000,50,477)
As such I calculate:
- cos^-1(42/50.5) = 33 deg
56.2deg/2 = 28.1 deg
Where am I going wrong?