Mohr’s Circle Calculator
Analyze Stress States Effectively
Principal Stress 1 ($σ₁$):
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Principal Stress 2 ($σ₂$):
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Max Shear Stress ($τ_{max}$):
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Principal Plane Angle:
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Move your mouse over the graph to see coordinates.
Mohr’s Circle is a simple way to analyze 2D stress at a point. It helps you:
- Find principal stresses (σ1σ1 and σ2σ2).
- Determine the maximum shear stress (τmaxτmax).
- Calculate the angle of the principal planes.
This tool automates these steps and shows an interactive graph.
Input Fields
- Normal Stress (σxσx):
Enter the normal stress along the xx-axis. Use positive for tensile stress and negative for compressive stress. - Normal Stress (σyσy):
Enter the normal stress along the yy-axis. Like before, positive is for tensile, and negative is for compressive. - Shear Stress (τxyτxy):
Enter the shear stress on the x−yx−y plane. Positive typically means counterclockwise.
Outputs
- Principal Stresses (σ1,σ2σ1,σ2):
These are the highest and lowest normal stresses the material experiences.
On the principal planes, the shear stress is always zero. The calculator displays these automatically. - Maximum Shear Stress (τmaxτmax):
This is the largest shear stress on the material. It occurs at ±45∘±45∘ from the principal planes. - Principal Plane Angle (θpθp):
This angle tells you how the principal planes are oriented relative to the xx-axis.
Graphical Features
Mohr’s Circle Plot
- The horizontal axis represents normal stress (σσ).
- The vertical axis represents shear stress (ττ).
Interactive Mouse Tracker
- Hover over the graph to see exact coordinates (σ,τσ,τ).
- Crosshairs move with your mouse to make the graph easier to read.
Principal Points
- The edges of the circle on the horizontal axis give the principal stresses (σ1,σ2σ1,σ2).
- The circle’s diameter equals 2 τmaxτmax.
Steps to Calculate
- Input Your Stress Values
Enter σxσx, σyσy, and τxyτxy in the fields. - Find the Center and Radius of the Circle
- The centre is the average of the normal stresses:
C=σx+σy2C=2σx+σy - The radius is based on the stresses:
R=(σx−σy2)2+τxy2R=(2σx−σy)2+τxy2
- The centre is the average of the normal stresses:
- Calculate Principal Stresses
- The maximum stress is:
σ1=C+Rσ1=C+R - The minimum stress is:
σ2=C−Rσ2=C−R
- The maximum stress is:
- Find Maximum Shear Stress
- The maximum shear stress is simply the circle’s radius:
τmax=Rτmax=R
- The maximum shear stress is simply the circle’s radius:
- Determine the Principal Plane Angle
- The angle of the principal planes is:
θp=12arctan(2τxyσx−σy)θp=21arctan(σx−σy2τxy)
- The angle of the principal planes is:
- See the Visualization
The graph shows the stress as a circle, displaying output values for quick reference.
Why Use This Calculator?
- Saves Time: No manual calculations.
- Accurate Results: Reduces errors in stress analysis.
- Interactive Graph: Move your mouse to explore stress points.
- Engineer’s Tool: Great for analyzing failure risks and material performance.