Book Reviews
Unlike most authors who have devoted their investigations to self-excited vibrations of fairly simple systems and have confined their treatment first of all to the determination of conditions under which self-excited vibrations are apt to arise, Dr. Tondl solves complex systems and establishes not only the conditions of initiation but also the kind of steady-state self-excited vibrations which are likely to be quite diverse in character in systems with several degrees of freedom. Such systems can vibrate in the first, in the second or simultaneously in both modes of vibration. The author also studies the behaviour of systems passing from one stable cycle to another, this transition being conditioned by a sudden change in some of the system parameters. The results of the theoretical analysis are amply supplemented by calculation of concrete cases and by analogue computer solutions. This combination makes it possible to follow the development of self-excited vibrations from the equilibrium position, and to examine the transition from one limit cycle to another. The analogue computer solution is also used for finding the separatrix surfaces which bound the domains of initial conditions leading to various kinds of motion. Another subject discussed in the monograph is the application of viscous dampers and dry-friction dampers to the task of damping various types of selfexcited vibrations.
The study brings a wealth of information that is of special interest for research scientists, and a number of novel findings undoubtedly very useful for practicing designers.
Note: Those interested in this monograph will likewise be interested in Tondl's earlier books: "On the Analysis of Nonlinear Systems Two-degrees of Freedom" (in Czech, with English summary), 82 pages, 1964, about $2.00 and "Some Problems of Rotor Dynamics" (in English), 434 pages, about $12.00, both published by Academia, Praha.