Mechanical vibrations [[electronic resource] ] : active and passive control / / Tomasz Krysinski, François Malburet

• Record Nr.: UNISA996216941603316
• Autore: Krysinski Tomasz
• Pubbl/distr/stampa: London ; ; Newport Beach, CA, : ISTE, c2007
• ISBN: 1-280-84767-0; 9786610847679; 0-470-61247-9; 0-470-39460-9; 1-84704-579-0
• Descrizione fisica: 1 online resource (391 p.)
• Collana: ISTE ; ; v.103
• Altri autori (Persone): MalburetFrançois
• Disciplina: 620.3; 621.8/11; 621.811
• Soggetti: Rotors - Vibration; Damping (Mechanics); Structural control (Engineering)
• Lingua di pubblicazione: Inglese
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Note generali: Description based upon print version of record.
• Nota di bibliografia: Includes bibliographical references and index.
• Nota di contenuto: Mechanical Vibrations; Table of Contents; Foreword; Preface; Part I. Sources of Vibrations; Chapter 1. Unbalance and Gyroscopic Effects; 1.1. Introduction; 1.1.1. Physico-mathematical model of a rotating system; 1.1.2. Formation of equations and analysis; 1.2. Theory of balancing; 1.2.1. Balancing machine or "balancer"; 1.2.1.1. The soft-bearing machine; 1.2.1.2. The hard-bearing machine; 1.2.2. Balancing in situ; 1.2.2.1. The method of separate planes; 1.2.2.2. The method of simultaneous planes - influence coefficients; 1.2.3. Example of application: the main rotor of a helicopter; 1.2.3.1. Bench test phase on the ground1.2.3.2. Test phase on a helicopter in flight; 1.3. Influence of shaft bending; 1.3.1. The notion of critical speed; 1.3.2. Forward precession of the flexible shaft; 1.3.2.1. Subcritical speed (: Ω<ωcr); 1.3.2.2. Resonance (: Ω<ωcr); 1.3.2.3. Supercritical speed (: Ω<ωcr); 1.3.3. Balancing flexible shafts; 1.3.4. Example of application: transmission shaft of the tail rotor of a ; helicopter; 1.4. Gyroscopic effects; 1.4.1. Forward or backward motion; 1.4.2. Equations of motion; 1.4.2.1. Natural angular frequencies (shaft off motion); 1.4.2.2. Critical speeds during forward precession1.4.2.3. Critical speeds during retrograde precession; Chapter 2. Piston Engines; 2.1. Introduction; 2.2. Excitations generated by a piston engine; 2.2.1. Analytic determination of an engine torque; 2.2.2. Engine excitations on the chassis frame; 2.2.2.1. Knocking load; 2.2.2.2. Pitch torque; 2.2.2.3. Review of actions for a four phase cylinder engine; 2.2.3. The notion of engine balancing; 2.2.3.1. Balancing the knocking loads; 2.2.3.2. Balancing the galloping torque; 2.3. Line shafting tuning; 2.3.1. The notion of tuning; 2.3.2. Creation of the equations2.3.3. Line shafting optimization; 2.3.3.1. Results for a non-optimized line shafting; 2.3.3.2. Results for an optimized line shafting; Chapter 3. Dynamics of a Rotor; 3.1. Introduction; 3.2. Description of the blade/hub relationship; 3.2.1. Some historical data; 3.2.2. Hinge link of the blade and the hub; 3.2.2.1. Formation of the equations for blade motion; 3.2.2.2. Homokinetic rotor; 3.3. Rotor technologies; 3.3.1. Articulated rotors; 3.3.1.1. Conventional articulated rotors; 3.3.1.2. Starflex® and Spheriflex® rotors; 3.3.2. Hingeless rotors; 3.3.3. Hingeless rotor3.4. Influence of alternate aerodynamic loads; 3.4.1. Load characterization; 3.4.1.1. Loads on a blade; 3.4.1.2. Dynamic response of a blade; 3.4.1.3. Loads transmitted by a mode i; 3.4.2. Analysis of loads transmitted to the rotor hub; 3.4.2.1. Loads transmitted to the rotor; 3.4.2.2. Synthesis of rotor loads on the rotor mast; 3.4.3. Dynamic optimization of a blade; 3.4.3.1. Introduction; 3.4.3.2. Study of the example of an optimized blade; 3.4.3.3. Contribution of the second flapping mode; Chapter 4. Rotor Control; 4.1. Introduction; 4.2. Blade motions; 4.2.1. Flapping equation - general case
• Sommario/riassunto: For all rotational machines, the analysis of dynamic stresses and the resulting vibrations is an important subject. When it comes to helicopters and piston engines, this analysis becomes crucial. From the design of parts working under stress to the reduction of the vibration levels, the success of a project lies mainly in the hands of the dynamicists. The authors have combined their talents and experience to provide a complete presentation on the issues involved. Part one describes, in concrete terms, the main dynamic phenomena and how they can be observed in reality. Part two presents infor

The last days of Kim Jong-il : the North Korean threat in a changing era / / Bruce E. Bechtol, Jr

• Record Nr.: UNINA9910812388403321
• Autore: Bechtol Bruce E. <1959->
• Pubbl/distr/stampa: Washington, District of Columbia : , : Potomac Books, , 2013
• ISBN: 1-61234-612-X
• Edizione: [First edition.]
• Descrizione fisica: 1 online resource (xv, 223 pages ) : illustrations, maps
• Disciplina: 951.93051092
• Soggetti: Security, International; Korea (North) Politics and government 1994-2011; United States Foreign relations Korea (North); Korea (North) Foreign relations United States; Korea (North) Military policy
• Lingua di pubblicazione: Inglese
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Note generali: Bibliographic Level Mode of Issuance: Monograph
• Nota di bibliografia: Includes bibliographical references (pages 197-214) and index.
• Nota di contenuto: Introduction -- Maintaining a rogue military: North Korea's military capabilities and strategy at the end of the Kim Jong-il era and South Korea's ability to counter the DPRK threat -- The sinking of the Cheonan and the shelling of Yeonpyeong Island: a case study of North Korea's asymmetric northern limit line strategy -- Planning for the unthinkable: countering a North Korean nuclear attack and management of postattack scenarios -- North Korea and support for terrorism: an evolving history -- Conclusion: the impact of the last years of the Kim Jong-il regime on the future of North Korea.
• Sommario/riassunto: Bruce Bechtol, Jr. contends that Kim Jong-il's regime (1994 - 2011) exacerbated the threats that North Korea posed, and still poses, to the world. Bechtol explains how North Korea presents important challenges on five key fronts.