LESSON 30.

Example: Draw the mohr’s stress circle for direct stresses of 70 MN/m2 (tensile) and 40 MN/m2 (compressive) and estimate the magnitude and direction of the resultant stresses and planes making angles of 300 and 700 with the plane of the first principal stress. Find also the normal and tangential stresses on these planes.

Solution:

Module 8 Lesson 30 Fig.1.1

  • Plot OL = 70 MN/m2 (tensile) and OM = 40 MN/m2  (compressive)

  • Draw NP at 600 and NP' at 1400

Case 1 :

  • σn  = OP = 42.5 MN/m2 (tensile)

  •  τ = PQ = 47.63 MN/m2 (shear)

  • σr = 63.83 MN/m2

  • φ = 48.260

       Case 2 :

  • σn  = OP' = 27.13 MN/m2 (compressive)

  •  τ = P'Q' = 35.35 MN/m2 (shear)

  • σr = 44.56 MN/m2

  • φ = 127.50

 

Last modified: Wednesday, 11 September 2013, 8:41 AM