The article presents a numerical and analytical method for
studying the bending-longitudinal vibrations of the load-bearing frame of
the locomotive frame of a complex configuration in the form of an elastic
rod of variable cross-section with variable mass, bending and longitudinal
stiffness, based on methods: piecemeal linear approximation, iterations and
the Boundary Element Technology. Numerical studies are performed in C #
and in MATHCAD 15.
