Vibrations in systems with a periodic structure is the subject of many ongoing research activities. This work presents the analysis of such systems with the help of the theory of representation groups by finite element methods, dynamic Compliance and dynamic rigidness methods, specially adjusted for the analysis of engineering structures. The approach presented in this book permits a simplification and facilitates the understanding of mechanical vibrations in various structures. The book includes extended studies of even complicated machinery structures with an emphasis on flight vehicle engines.

Zusammenfassung
In this book, regular structures are de ned as periodic structures consisting of repeated elements (translational symmetry) as well as structures with a geom- ric symmetry. Regular structures have for a long time been attracting the attention of scientists by the extraordinary beauty of their forms. They have been studied in many areas of science: chemistry, physics, biology, etc. Systems with geometric symmetry are used widely in many areas of engineering. The various kinds of bases under machines, cyclically repeated forms of stators, reduction gears, rotors with blades mounted on them, etc. represent regular structures. The study of real-life engineering structures faces considerable dif culties because they comprise a great number of working mechanisms that, in turn, consist of many different elastic subsystems and elements. The computational models of such systems represent a hierarchical structure and contain hundreds and thousands of parameters. The main problems in the analysis of such systems are the dim- sion reduction of model and revealing the dominant parameters that determine its dynamics and form its energy nucleus. The two most widely used approaches to the simulation of such systems are as follows: 1. Methods using lumped parameters models, i.e., a discretization of the original system and its representation as a system with lumped parameters [including nite-element method (FEM)]. 2. The use of idealized elements with distributed parameters and known analytical solutions for both the local elements and the subsystems.

Inhalt
Mechanical Vibratory Systems with Hierarchical Structure. Simulation and Calculation Methods.- Systems with Lumped Parameters.- Vibrations of Regular Systems with Periodic Structure.- Vibrations of Systems with Geometric Symmetry. Quasi-symmetrical Systems.- Systems with Distributed Parameters.- Basic Equations and Numerical Methods.- Systems with Periodic Structure.- Systems with Cyclic Symmetry.- Systems with Reflection Symmetry Elements.- Self-Similar Structures.- Vibrations of Rotor Systems with Periodic Structure.- Vibrations of Regular Ribbed Cylindrical Shells.