"In engineering, the deformation of a body is specified using the concept of normal and shear strain. In this chapter we will define these quantities and show how they can be determined for various types of problems."

DEFORMATION
A CHANGE IN SHAPE

DISPLACEMENT
A DISTANCE AND A DIRECTION OF MOTIONDESCRIBING A CHANGE IN POSITION FROM A STARTING POINT TO A FINAL LOCATION.

NORMAL
IN MECHANICS, NORMAL OFTEN MEANS PERPENDICULAR OR AT RIGHT ANGLES TO A SURFACE OR A DIRECTION. NORMAL CAN ALSO MEAN NOMINAL OR AVERAGE.

NORMAL STRAIN
A COMPONENT OF THE STRAIN THAT IS PERPENDICULAR (NORMAL) TO A PLANE OF REFERENCE

SHEAR

SHEAR STRAIN

STRAIN