General Concepts of
Stress and Strain
In extending the direct method of stress analysis presented in
previous modules to geometrically more complex structures, it will be
convenient to have available somewhat more general mathematical
statements of the kinematic, equilibrium, and constitutive equations;
this is the objective of the present chapter. These equations also
form the basis for more theoretical methods in stress analysis, as
well as for numerical approaches such as the finite element method.
We will also seek to introduce some of the notational schemes used
widely in the technical literature for such entities as stress and
strain. Depending on the specific application, both index and matrix
notations can be very convenient; these are described in a separate module.