Bulk modulus

  • illustration of uniform compression

    the bulk modulus ( or ) of a substance is a measure of how resistant to compression that substance is. it is defined as the ratio of the infinitesimal pressure increase to the resulting relative decrease of the volume.[1] other moduli describe the material's response (strain) to other kinds of stress: the shear modulus describes the response to shear, and young's modulus describes the response to linear stress. for a fluid, only the bulk modulus is meaningful. for a complex anisotropic solid such as wood or paper, these three moduli do not contain enough information to describe its behaviour, and one must use the full generalized hooke's law.

  • definition
  • thermodynamic relation
  • measurement
  • selected values
  • microscopic origin
  • references
  • further reading

Illustration of uniform compression

The bulk modulus ( or ) of a substance is a measure of how resistant to compression that substance is. It is defined as the ratio of the infinitesimal pressure increase to the resulting relative decrease of the volume.[1] Other moduli describe the material's response (strain) to other kinds of stress: the shear modulus describes the response to shear, and Young's modulus describes the response to linear stress. For a fluid, only the bulk modulus is meaningful. For a complex anisotropic solid such as wood or paper, these three moduli do not contain enough information to describe its behaviour, and one must use the full generalized Hooke's law.