Nonlinear Effects in Technical Diagnostics

Hardcover, 303 pages, 177 colour figures in text, NOT ex-library. Signed & inscribed by one of the Authors. Minor handling wear, book is clean and bright with unmarked text, free of stamps, firmly bound. Issued without a dust jacket. -- The book explores the complexities of diagnosing technical systems through nonlinear dynamics. It begins with fundamental concepts and definitions, including nonlinearity notions, models and signal prediction. It progresses to the identification of dynamic nonlinear models, presenting both theoretical frameworks and practical simulation tests. Through detailed examples, the authors elucidate simple nonlinear models in the diagnostics of rotating systems, discussing factors such as damping, torque disturbances, and critical speeds. The text also delves into advanced topics such as the application of the Kalman filter for monitoring vibrations in hydrodynamic bearings and using coherence functions to measure nonlinear disturbances in composite structures. Moreover, the book examines the role of technical stability theory in constructing monitoring systems, showcasing simulation experiments and their outcomes. In the later chapters, the authors focus on the nonlinear diagnostic modeling of turbine sets, including FEM models, numerical realization, and determination of model adequacy intervals, backed by both theoretical and experimental analyses. This comprehensive text is essential for engineers and researchers, offering practical insights and advanced methodologies for improving fault detection and system performance in technical diagnostics. -- Contents: 1. Introduction 2. Basic definitions and formulas 3. Identification of a dynamic nonlinear model [Identification of a linear model; Solution of a system of weakly-nonlinear ordinary differential equations; General formulation of the task of the nonlinear model identification; Simulation tests of nonlinear responses under disturbance conditions; Identification of the signal model relationship by the Kalman filtration technique] 4. Examples of simple nonlinear models in diagnostics of rotating systems [Nonlinear model of motion of the rotor on stiff supports; Influence of damping on the critical state in the diagnostic model; Modern methods of welding as a factor causing nonlinear damping of a rotating shaft; Model of a rotor on elastic supports; Influence of an axial force on a critical state; Modelling of the torque disturbances, critical speeds of the second kind; Simple dynamic model of the power transmission system; Modeling of non-coaxiality errors] 5. Kalman filtration in diagnostics of shaft necks vibrations in the hydrodynamic bearing [Characteristics of the tested object; Application of the Kalman filter for monitoring the slide bearing state; Experimental tests; Analysis of results; Conclusions] 6. Coherence function as a nonlinear disturbances measure in diagnostics of a composite structure damage [Tested object; On advisability and possibility of applying the vibroacoustic technique; Looking for a vibrational measure; Active diagnostic experiment; Conclusions] 7. Application of the technical stability theory in constructing monitoring systems [Methodological grounds for constructing monitoring system based on the stability theory; Methods of testing the technical stability tools in constructing monitoring systems; Simulation experiments; Assessment of the simulation results; Conclusions] 8. Nonlinear diagnostic model of a turbine set [Formulation of the problem; Model of the supporting structure; Transformation of characteristics; Methodology of nonlinear calculations; Concluding remarks] 9. Numerical realisation of nonlinear model of a turbineset [Preliminary remarks; FEM model of the line of rotors; FEM model of journal bearings; Algorithm of calculations; Discussion of the final model; Computer codes] 10. Determination of adequacy intervals of the model [Preliminary remarks; The laboratory rotor; Large power machine] 11. Summary. …