Question

The number of independent elastic constant is ______

(a) 2

(b) 5

(c) 0

(d) 6

The question was posed to me in a national level competition.

My question is based upon Generalised Hooke’s Law in section Elements of Elasticity of Geotechnical Engineering I

Answer 1

The correct option is (a) 2

Easiest explanation: Harr in 1966 showed that by a series of rotations of axes, the number of independent constants for a homogeneous and isotropic body is only two.