

The way I recall it being taught was that “elastic deformation” was deformation that didn’t compromise the integrity of the original shape of the object (typically a rigid body in most of my textbook’s examples, which could be where our understandings are deviating).
One example my professor used to illustrate the concept in-person was with a paper clip. Bending one end the paper clip ever so slightly (such that it springs back into its original shape when you let go) was “elastic deformation” of the material. Bending the end of the paper clip enough such that it can’t return to its original shape afterward was “plastic deformation”.











“I like to close the bathroom door when I’m taking a shower. Doesn’t mean I’m doing anything immoral in there. I’m just entitled to privacy.”
They can extrapolate from there if they’ve got two brain cells to rub together.