Strain measurements are made in a displacement-controlled experiment on specific samples so they undergo uniform deformation. Tensile testing is a very common method used for making strain measurements
The mechanical response of different material types is measured this way to estimate their material properties
But is the strain measured during the experiments a true estimate of strain or is it different from the strain developed in the material? If different, then is there a way to estimate the "true" measure of strain in the body?
In this lesson, we will learn the differences and the relations between true and engineering strains.
Here are the accompanying handout slides for this lesson.