3 - Mohrs Circle

Question 1

Equation of Mohr’s Circle

Answer 1

Question 2

Drawing Mohr’s Circle

Answer 2

• Normal stress (σ) is plotted on the x-axis
• Shear stress (tau) is plotted on the y-axis
• Maximum shear stress is equal to the radius, R
• The center of the circle, C, always sits on the x-axis where x = σavg and y = 0
• The principal stresses lie where the circle intersects the x-axis
• The state of plane stress at any inclined section, (inclined at angle θ), is defined by the corresponding point on the circle
• Sign Convention:
  
  • σ is positive to the right.
  • Tau is positive downward.

Question 3

Mohr’s Circle Calculation Steps

Answer 3

1. Find centre point (sigma-avg,0)
2. Find R
3. Find min and max points using above
4. Find angle