### What Is An Elastic Modulus? Types Of Elastic Modulus

**What Is An Elastic Modulus?**

**The Elastic modulus is a measure of a material’s stiffness or rigidity. It is defined as the ratio of stress to strain below the proportional limit. The modulus of elasticity is the slope of the stress-strain curve in the range of linear proportionality of stress to strain. ** The greater the modulus, the stiffer the material, and the smaller the elastic strain that results from the application of a given stress. This parameter is an important design parameter used for computing elastic deflections. The Elastic modulus is also known as modulus of elasticity and is sometimes referred to as Young’s modulus. It can be used in measuring resistance in materials to elasticity or deformation, for example, a material with low moduli is floppy and will stretch a lot when pressure forces to. High modulus materials are the opposite as they stretch very little when pulled. Elastic Modulus, or simply Modulus, is used for quantifying a material’s ability to resist a non-permanent (elastic) deformation or strain. When tested under stress, such materials first exhibit elastic properties. The materials will stretch and return to their previous state once the stress is removed. However, if the material is stressed too far, it will stretch beyond the elastic region and the elastic limit to then enter the plastic region where they will exhibit permanent deformation.

**Types Of Elastic Modulus**

The measurement of stress and strain, including the directions in which they are applied, allows for various elastic moduli to be defined. **The main ones are Young’s modulus (E),** which measures the ability of an object to deform along an axis when opposing forces are applied; **the shear modulus or modulus of rigidity**, which measures an object’s ability to shear when acted upon by opposing forces; and **the bulk modulus (K),** which measures an object’s ability to deform in all directions when uniformly loaded in all directions. Additionally, there are two other elastic moduli, **Lamé’s first parameter, λ, and P-wave modulus,** M. Homogeneous and isotropic materials have their linear elastic properties described by two elastic moduli, and any pair can be chosen. Inviscid fluids cannot support shear stress, so their shear modulus is always zero and their Young’s modulus is also zero. In some texts, the modulus of elasticity is referred to as the elastic constant, while the inverse quantity is referred to as elastic modulus.

**Applications Of Elastic Modulus**

The Elastic Modulus has various uses including in engineering and medical science to calculate the stretch of a material and potential energy stored, determine a material’s response to stress, and characterization of biological materials such as cartilage and bone.