Question

For a linear, elastic, isotropic material, the number of independent elastic constants is

• A. $1$
• B. $2$
• C. $3$
• D. $4$

Answer 1

The correct option is B $2$

Isotropic materials have same properties in all directions. The number of independent elastic constants for such materials is 2. Out of E, G, K and μ, if any two constant is known for any linear elastic and isotropic material than rest two can be derived. Examples are steel, aluminium, copper, gold, etc. Orthotropic materials refers to layered structure such as wood or plywood. The number of independent elastic constants for such materials
is 9.
Non-isotropic or anisotropic materials have different properties in different directions. They show nonhomogeneous behaviour. The number of independent elastic constants is 21.