The presentment should be as simple as possible, but not a bit simpler.
Albert Einstein Introduction The power of the variational approach in
mechanics of solids and structures follows from its versatility: the
approach is used both as a universal tool for describing physical
relationships and as a basis for qualitative methods of analysis [1].
And there is yet another important advantage inherent in the variational
approach - the latter is a crystal clear, pure and unsophisticated
source of ideas that help build and establish numerical techniques for
mechanics. This circumstance was realized thoroughly and became
especially important after the advanced numerical techniques of
structural mechanics, first of all the finite element method, had become
a helpful tool of the modern engineer. Certainly, it took some time
after pioneering works by Turner, Clough and Melos until the finite
element method was understood as a numerical technique for solving
mathematical physics problems; nowadays no one would attempt to question
an eminent role played by the variational approach in the process of
this understanding. It is a combination of intuitive engineer thinking
and a thoroughly developed mathematical theory of variational calculus
which gave the finite element method an impulse so strong that its
influence can still be felt. It would be too rash to say that there are
few publications or books on the subject matter discussed in this book.