ABSTRACT
Much like the methods described in Section 1.4, the finite element method (FEM) provides an approximate solution to the boundary value problem, which determines the relationship between stresses and strains and the acting forces in a loaded body. There are a number of ways to derive the main equations of the FEM that depend on its usage: in application to conservative systems, one may use either the principle of minimum of potential energy, or the principle of virtual work, in nonconservative systems, e.g., involving inelastic materials or friction, one must use the principle of virtual work or its equivalent-the Galerkin method.
