Mechanical Engineering

Maximum In-Plane Shear Stress

Find the radius of Mohr’s circle for a plane-stress state.

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Calculate maximum in-plane shear stress magnitude or choose another supported quantity.

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Use decimals or scientific notation, such as 1.2e3. Calculations update as you type.

Maximum in-plane shear stress magnitude

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Enter the known values to see the result.

Use a plane-stress state with consistent signs. This is the maximum shear within the original plane, not necessarily the absolute maximum shear in three dimensions. For absolute maximum shear, include the zero out-of-plane principal stress.

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Source & review

Difficulty

Intermediate

Read time

5 min

Prerequisites

Basic algebra, mechanics, and consistent SI units

Review statusNeeds review

Source

Donney Fan — MECH 360 — Mechanics of Materials

Reference equation: Stress Transformations — Maximum In-Plane Shear Stress. FormuLab wrote new explanations, assumptions, applications, and numerical examples.

Definition

Understanding the core concept

The radius of Mohr’s circle measures how large the in-plane shear component can become as the axes rotate. Equal biaxial normal stress alone has zero in-plane shear, even though three-dimensional shear extrema can still be nonzero.

Variables & Units

Understanding each component
SymbolMeaningUnits
Maximum in-plane shear stress magnitude
Signed normal stress on the x face
Signed normal stress on the y face
Signed in-plane shear stress

Real-World Applications

Where this formula is used in practice

Mohr’s circle

Find its radius directly from stress components.

Stress interpretation

Distinguish in-plane from absolute maximum shear.

Worked Example

Step-by-step calculation with real numbers

Problem

For σx = 80 MPa, σy = 20 MPa, and τxy = 30 MPa, find the maximum in-plane shear magnitude.

Given

Solution

1
2

Final Answer

FormuLab is a study reference. Verify formulas, units, assumptions, and course-specific conventions before relying on them.

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