The bulk modulus is a constant that describes how compressible a substance is. It is defined as the ratio of an increase in pressure to a reduction in the volume of a substance. The bulk modulus, together with Young’s modulus, shear modulus, and Hooke’s law, characterises a material’s reaction to stress or strain.
In equations and tables, bulk modulus is usually denoted by K or B. While it may be applied to any substance, it is most commonly used to explain the behaviour of fluids. It may be used to forecast compression, compute density, and infer the types of chemical bonding inside a substance indirectly.
Because a compressed material returns to its original volume once the pressure is removed, the bulk modulus is considered a descriptor of elastic characteristics.
Pascals (Pa) or newtons per square metre (N/m2) in the metric system, or pounds per square inch (PSI) in the English system, are the units for the bulk modulus.
Bulk Modulus
The bulk modulus, together with Young's modulus, shear modulus, and Hooke's law, characterises a material's reaction to stress or strain.