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Stress transformation screen

Plane-stress Mohr’s Circle

Inputs

Signed plane-stress component; tension positive under the stated convention.
Signed plane-stress component at the same point.
Signed shear stress at the same point and under one stated convention.

Results

Mohr circle center stress

60

Mohr circle radius / max in-plane shear

50

Maximum principal stressσ₁

110

Minimum principal stressσ₂

10

One principal-plane orientation

26.565

Mohr-circle double angle to principal plane

53.13

Mohr-circle double angle to max-shear plane

143.13

σavg = (σx + σy)/2; R = √[((σx−σy)/2)² + τxy²]; σ1,2 = σavg ± R; 2θp = atan2(2τxy, σx−σy); 2θs = 2θp + 90°

A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.

Nearby: Axial response · Beam deflection & reactions · Elastic stability · Solid-shaft torsion

Method

Formula, when it applies, and when it does not

Resolve a plane stress state into circle center/radius, principal stresses, maximum in-plane shear, and one principal-plane orientation.

σavg = (σx + σy)/2; R = √[((σx−σy)/2)² + τxy²]; σ1,2 = σavg ± R; 2θp = atan2(2τxy, σx−σy); 2θs = 2θp + 90°

When

  • Plane stress
  • One point
  • Signed stress components
  • Elastic transformation only

Don’t

  • This transforms one entered plane-stress state at one point. The reported angle follows the entered sign convention and is one of two orthogonal principal-plane orientations; the two Mohr-circle double-angle outputs are shown explicitly. It excludes 3D stress, stress gradients, principal strain, material failure criteria, buckling, fatigue, fracture, local concentration, and any design or compliance decision.
Boston University stress-transformation lesson