SUMMARYProcedures for plotting computer generated interferograms from the results of ÿnite-element analysis based on the principles of optical holography can provide a realistic view of dynamic processes taking place in the analysed structures. Such visualization is based on a solid physical background, does not require animation for representing dynamic processes, and is also important from the point of view of interpretation of experimental holograms.The numerical method for obtaining time-averaged digital interferograms for structural dynamics applications is presented. Intensity mapping as well as the methods of digital stroboscopic analysis are used for plotting clearer images due to the fact that the intensity of higher interference bands decreases rapidly with the growth of vibration amplitudes.The digital time averaging of intermediate states of the moving surface together with varying direction of incident laser beam and estimation of di use and specular re ection phenomena enables the generation of realistic interferograms. Such a procedure is scalable in parallel computations and applicable to a wide variety of problems.

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It is known that in the vibroimpact system at the chosen values of parameters linear relationship between impact velocities and eigenfrequencies may exist. The purpose of this paper is to reveal the qualities of the systems of this type. Investigations are performed by analytical and numerical methods. It is determined that in the systems of this type nonlinear solutions with infinite series of harmonics exist. Multivalued stable and unstable regimes do not exist in the systems. The obtained analytical relationships enabled to reveal new qualities of the systems and to make useful conclusions. Keywords: characteristics of impact velocity and eigenfrequencies, free and decaying vibrations, phase trajectories of motions, harmonics of motions up to infinity.

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