13th junio 2018 | 3 Min read time

Thomas Young: Introducing Young’s Modulus

Today we celebrate the contribution that Thomas Young made to the field of engineering, born exactly 245 years ago in 1773 (13 June 1773 – 10 May 1829).

Young was a British polymath and physician and has been described as "The Last Man Who Knew Everything" having made notable scientific contributions to solid mechanics, energy, fields of vision, light, physiology, language, musical harmony, and Egyptology. For understanding materials, Young defined a type of elastic moduli, defined as Young’s Modulus.

Young’s Research

Young's Modulus (also known as Tensile Modulus, Elastic Modulus or Traction Modulus)

Young described the characterization of elasticity that came to be known as Young's Modulus, denoted as E, in 1807. This is a ratio of the stress divided by the strain on a material. It is a measure of the stiffness of a material (a stiffer material has a higher value of Young’s Modulus).

Straining a material beyond the elastic limit causes it to ‘yield’. Above the yield point the material is in its plastic range. Some materials have very clear yield points that can be illustrated graphically using experiments using apparatus listed below, others (such as light alloys) do not have such clear yield points, so engineers use a ‘proof stress’ or ‘percentage stress’ value.

Students can learn more about Young’s Modulus using the following TecQuipment apparatus:

Elastic Modulus

The modulus of elasticity is a number that measures a material’s resistance to being deformed elastically (ie non-permanently) when a force is applied to it. Forms of elastic modulus include:

  • Young’s Modulus
  • Shear Modulus
  • Bulk Modulus
  • Axial Modulus
  • Lame’s First Parameter
  • P-wave Modulus