This paper describes the additional features of discrete models of various DOF systems to solve nonlinear
dynamical problems of complex-compound buildings and structures including elements of significant flexibility
(bridges, pylons and supports of power transmission lines, pipe line crossings, guyed masts etc.). Qualitative
and quantitative differences between linear solutions (which are popular among FEM designers) and nonlinear
solutions (depending on geometrical, physical and constructive nonlinearities) are discussed. It is analyzed the
time-history models of different combinations of mention structures with the adjacent subsystems, damping
devices (well-known and the most-recently-used), static and dynamic loads and effects (including moving
loads).
There is also presented experimental and theoretical approach of damages determination for rod elements in
the spatial structure by the dynamic diagnosis method (e.g. for bridges crane with the big span).
