Question

The principal material axes that are normal to the _______

(a) Co-ordinates

(b) Number of nodes

(c) Principal axes

(d) Plane of symmetry

I had been asked this question in examination.

This intriguing question originated from Two Dimensional Problems topic in section Two Dimensional Problems using Constant Strain Triangles of Finite Element Method

Answer 1

Correct option is (d) Plane of symmetry

The explanation: Orthotropic materials are a subset of anisotropic; their properties depend upon the direction in which they are measured. Orthotropic materials have three planes of symmetry. That is normal to principal material axes.