Young's Modulus, also known as the elastic modulus or modulus of elasticity, is a measure of a material's stiffness or ability to resist deformation when subjected to an external force. It is defined as the ratio of stress (force per unit area) to strain (change in length per unit length) in the linear region of a material's stress-strain curve.
The formula for calculating Young's Modulus is:
E = σ / ε
where E is Young's Modulus, σ (sigma) is the stress, and ε (epsilon) is the strain. This formula is based on Hooke's Law, which states that within the elastic limit, the stress is directly proportional to the strain.
The unit of measurement for Young's Modulus is the same as that for stress, which is typically expressed in pascals (Pa) or newtons per square meter (N/m2). In some industries, it may also be expressed in pounds per square inch (psi) or gigapascals (GPa).
Young's Modulus is an important property of materials because it helps engineers and scientists predict how a material will behave under different types of stress, such as tension, compression, or bending. It also allows for the comparison of different materials and helps in the selection of the most suitable material for a specific application.
Generally, as temperature increases, the Young's Modulus of a material decreases. This is due to the increased thermal motion of the atoms within the material, which makes it easier for the material to deform under stress. However, this relationship may vary depending on the type of material and its composition. In some cases, temperature changes may also cause a material to undergo phase changes, which can significantly affect its Young's Modulus.