Elasticity (Young's) Modulus

Discovery

The concept of the modulus of elasticity was first introduced by Thomas Young in 1807.

Definition

Also referred to in some sources as Young's modulus, the modulus of elasticity (E) is a value that represents a material's resistance to deformation under load.

This value (E) serves as a measure of how stiff or flexible a material is. A higher value indicates that the material will deform less compared to one with a lower value.

Determination and Base Unit

This value is calculated from the stress-strain graph obtained after a stress-strain test. According to this, the slope of the linear region of the stress-strain curve is equal to the modulus of elasticity of the material. This relationship is known as Hooke's Law.

Hooke's Law is valid only within the linear region. In regions where the linear relationship breaks down, this law loses its validity. In nonlinear regions (where plastic displacements occur under region), the modulus of elasticity varies depending on the applied load. The SI unit of the modulus of elasticity is the pascal (Pa).

Hooke's Law Equation

Example Materials

E_Steel = 2×10¹¹ N/m²

E_Aluminum = 7×10¹⁰ N/m²