Stress, Strain and Elastic Moduli

How solid materials deform under force, and how to measure their stiffness.

Stress and Strain

  • Stress — internal restoring force per unit area (F/A)
  • Strain — fractional change in dimension (length, volume, or shape)

Hooke's Law

Within the elastic limit, stress is directly proportional to strain.

Elastic Moduli

ModulusApplies To
Young's ModulusChange in length
Bulk ModulusChange in volume
Shear ModulusChange in shape
Lesson 18 of 31
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