Open Tools · Mechanical, structural, civil
Stressturn: free online Mohr circle calculator
Stressturn turns a stress or strain state into everything an engineer reads from it: principal values and directions, Mohr circles, maximum shear, octahedral stress and safety factors under six failure criteria. Drag around the circle to rotate the element and watch the faces change.
It also reduces strain-gauge rosettes to principal strains and stresses, solves thick-walled cylinders and interference fits, and finds the stresses in spinning discs. Stress concentration uses a factor you enter. Every result can be checked in the Verify view.
What Stressturn can do
- 2-D and 3-D Mohr circles with principal stresses and directions by eigen-decomposition
- Maximum shear, octahedral stresses and invariants that stay fixed under rotation
- Tresca, von Mises, maximum normal, Mohr-Coulomb and brittle Coulomb-Mohr and modified Mohr safety factors
- Rectangular, delta and arbitrary strain-gauge rosettes in plane stress or plane strain
- Thick-walled cylinders, interference fits and rotating discs with stress profiles
- Study files, CSV, SVG and PNG exports and a printable report
How we verify Stressturn
Stressturn is checked against 143 independent reference cases. Where a reference answer exists you can run every check yourself on the Verify page, and the Stressturn user guide documents every feature and limitation.
The Verify view runs 143 reference cases in your browser and shows, for each, what is checked, the independent reference, the computed value, the difference, the tolerance and PASS or FAIL. The same cases are run by the project’s automated tests.
Stressturn is part of Open Tools, the free engineering tools that run in your browser.
Professional use. Results are for education and preliminary design. They must be checked by a qualified professional, and they are not a substitute for code-compliant design or licensed engineering judgement.