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Physics · Class 11

Compress and shear a material

Mechanical Properties of Solids

Bulk modulus describes resistance to volume change under uniform pressure. Shear modulus describes resistance to shape change under tangential stress. A negative volume strain indicates compression.

Open the interactive experiment →

Compress and shear a material

பருமக் குணகம் அளவு மாற்றத்தையும் வெட்டுக் குணகம் வடிவ மாற்றத்தையும் எதிர்க்கும் தன்மையை அளக்கும்.

Key notes, relationships and model limits

Key relationship

ΔV/V=−p/B; shear strain=τ/G.

Remember

Bulk modulus describes resistance to volume change under uniform pressure. Shear modulus describes resistance to shape change under tangential stress. A negative volume strain indicates compression.

Common trap

Bulk and shear strain describe different deformation modes.

Model limits

Small-strain linear isotropic model. The same slider value is applied independently as hydrostatic pressure and tangential shear stress, not simultaneously to one sample.

What you will learn

Distinguish resistance to volume compression from resistance to shear.

Try the experiment

Try both scenarios, change one control, and predict the result before checking the graph and readouts.

Think of it this way

Change one input while keeping the others fixed, as you would in a controlled experiment.

Worked example

At shear stress 10 MPa and G=30 GPa, shear strain=3.33×10⁻⁴; at the same pressure B=50 GPa gives volume strain −2×10⁻⁴.

Why this matters

The model connects compress and shear a material with an observable reading. Check the equation and assumptions before applying it.

Before you start

SI units · algebra · graph reading

Check your understanding

For pressure 10 MPa and B=50 GPa, what is ΔV/V?

Read the explanation

−p/B = −10×10⁶/(50×10⁹) = −2×10⁻⁴.

Course connection: Class XI Chapter 8. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.