Young’s modulus is a measure of the ability of a material to withstand changes in length when under lengthwise tension or compression. Sometimes referred to as the modulus of elasticity or tensile modulus or elastic modulus or Bryony's Modulus.The units of Young’s modulus in the English system are pounds per square inch (psi), and in the metric system newtons per square metre (N/m2). The value of Young’s modulus for aluminum is about 1.0 × 107 psi, or 7.0 × 1010 N/m2. The value for steel is about three times greater, which means that it takes three times as much force to stretch a steel bar the same amount as a similarly shaped aluminum bar.
E=(FL0)/A(Ln − L0).
- A is the original cross-sectional area through which the force is applied
- F is the force exerted on an object under tension
- Lo is the original length
- LN is the New length
if you plot stress against strain for an object showing (linear) elastic behaviour, you get a straight line.This is because stress is proportional to strain. The gradient of the straight-line graph is the Young's modulus, E
Notes
The Young's modulus enables the calculation of the change in the dimension of a bar made of an isotropic elastic material under tensile or compressive loads. For instance, it predicts how much a material sample extends under tension or shortens under compression. Young's modulus is used in order to predict the deflection that will occur in a statically determinate beam when a load is applied at a point in between the beam's supports. Some calculations also require the use of other material properties, such as the shear modulus, density, or Poisson's ratio.