Question

In solid mechanics, which option is not a characteristic of a plane stress problem in the XYZ Cartesian system?

(a) One dimension is very small compared to the other two dimensions

(b) All external loads are coplanar

(c) Strain along any one direction is zero

(d) Stress along any one direction is zero

I had been asked this question in unit test.

My doubt is from Plane Elasticity in chapter Plane Elasticity of Finite Element Method

Answer 1

Correct choice is (c) Strain along any one direction is zero

The explanation: An example of a plane stress problem is provided by a plate in the XYZ Cartesian system that is thin along the Z-axis. It is acted upon by external loads lying in the xy plane (or parallel to it) that are independent of the Z coordinate. Thus, stresses and strains are observed in all directions except that the stress is zero along the Z-axis.