ABSTRACT
As a result of positioning of masses, even a relatively simple frame is represented by a design scheme with a number of degree of freedoms (DOFs) in the order of tens, and the problem of dynamic calculation appears to be cumbersome. For calculating the stress-strain state of a vibrating elastic system, besides the force method, the dynamic displacement method may be used. The assumption about the at-rest condition of a system at the initial point in time was entered for simplicity of substantiation of the method. The dynamics of structures with multiple DOFs was studied with disregard for energy dissipation. Lord Rayleigh, in the book The Theory of Sound, pointed out that the form of damping matrix is convenient for analysis of the multi-DOF system’s response, because it enables us to obtain the set of uncoupled differential equations governing modal coordinates.
