Smart Helicopter Rotors
Smart Helicopter Rotors

Author: Ranjan Ganguli

Publisher: Springer

Published: 2015-12-16

Total Pages: 264

ISBN-13: 3319247689

DOWNLOAD EBOOK

Exploiting the properties of piezoelectric materials to minimize vibration in rotor-blade actuators, this book demonstrates the potential of smart helicopter rotors to achieve the smoothness of ride associated with jet-engined, fixed-wing aircraft. Vibration control is effected using the concepts of trailing-edge flaps and active-twist. The authors’ optimization-based approach shows the advantage of multiple trailing-edge flaps and algorithms for full-authority control of dual trailing-edge-flap actuators are presented. Hysteresis nonlinearity in piezoelectric stack actuators is highlighted and compensated by use of another algorithm. The idea of response surfaces provides for optimal placement of trailing-edge flaps. The concept of active twist involves the employment of piezoelectrically induced shear actuation in rotating beams. Shear is then demonstrated for a thin-walled aerofoil-section rotor blade under feedback-control vibration minimization. Active twist is shown to be significant in reducing vibration caused by dynamic stall. The exposition of ideas, materials and algorithms in this monograph is supported by extensive reporting of results from numerical simulations of smart helicopter rotors. This monograph will be a valuable source of reference for researchers and engineers with backgrounds in aerospace, mechanical and electrical engineering interested in smart materials and vibration control. Advances in Industrial Control aims to report and encourage the transfer of technology in control engineering. The rapid development of control technology has an impact on all areas of the control discipline. The series offers an opportunity for researchers to present an extended exposition of new work in all aspects of industrial control.

Smart Structures Theory
Smart Structures Theory

Author: Inderjit Chopra

Publisher: Cambridge University Press

Published: 2014

Total Pages: 925

ISBN-13: 052186657X

DOWNLOAD EBOOK

This book focuses on smart materials and structures, which are also referred to as intelligent, adaptive, active, sensory, and metamorphic. The ultimate goal is to develop biologically inspired multifunctional materials with the capability to adapt their structural characteristics, monitor their health condition, perform self-diagnosis and self-repair, morph their shape, and undergo significant controlled motion.

A Study of the Thermal Effects in a Smart Structure Helicopter Rotor
A Study of the Thermal Effects in a Smart Structure Helicopter Rotor

Author:

Publisher:

Published: 1999

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

One concept being considered for active noise and vibration control of helicopter rotors is a trailing edge flap design driven by a high-displacement piezoelectric actuator device. The proposed device requires an 800-V power supply and draws a current on the order of .3 A. Thus, depending on the duty cycle and efficiency of the mechanism, some portion of the 240 W of electrical input energy will be converted to heat. This study provides an initial estimate of the temperatures that may be encountered if no provisions are made for cooling the actuator. Also included are a discussion of the heat transfer calculation, assuming conduction and radiation as the dominant modes, and a description of HEAT 8, the computer code used.

Helicopter-type Rotor Decelerators
Helicopter-type Rotor Decelerators

Author: R. R. Tyndall

Publisher:

Published: 1963

Total Pages: 24

ISBN-13:

DOWNLOAD EBOOK

Helicoptr-type rotors appear attractive for the deceleration, trajectory control, gliding descent and final recovery of almost all types of aero space payloads. The potential of rotors is based upon (1) their inherent virtues of L/D gliding capability, controllability, and soft, flared landing; (2) past experience with uncontrolled rotor-decelerated air-dropped stores; and (3) helicopters having the capabilities of control, autorotation, and flare-out to land. Aero nautical Systems Division, as well as other Government agencies, believes that rotor decelerators have potential, particularly in light of the desired expansion of limited war capability, and is conducting applied research to explore the basic feasibility of using rotors for aerospace payload recovery. This effort involves both wind tunnel testing in the transonic-super sonic range, and free-flight testing at deployment speeds up to Mach 0.9 and analyses. To date, wind tunnel tests have demonstrated the deployment, operating, and drag characteristics of an eight-foot diameter rotor decelerator through a Mach number range from 0.5 to 1.5. Analyses have indicated that rotors, as well as providing subsonic performance capability, may have potential as hypersonic glide and drag devices. Thus, rotor decelerator potential embraces the spectrum ranging from relatively low-speed aerial delivery of payloads to suborbital and orbital space vehicle recovery. (Author).

Adaptronics and Smart Structures
Adaptronics and Smart Structures

Author: Hartmut Janocha

Publisher: Springer Science & Business Media

Published: 2013-11-11

Total Pages: 448

ISBN-13: 3662038196

DOWNLOAD EBOOK

Adaptronics is the term encompassing technical fields that have become known internationally under the names "smart materials", "intelligent structures", and "smart structures". Adaptronics contributes to the optimisation of systems and products. It bridges the gap between material and system or product, and incorporates the search for multi-functional materials and elements and their integration in systems or structures. The authors of this book have taken on the task of displaying the current state of the art in this fascinating field. The system components, actuators, sensors and controllers, technical fundamentals, materials, design rules and practical solutions are all described. Selected sample applications are also presented and current development trends are demonstrated.

Smart Materials and Structures
Smart Materials and Structures

Author: M.V. Gandhi

Publisher: Springer Science & Business Media

Published: 1992-05-31

Total Pages: 330

ISBN-13: 9780412370106

DOWNLOAD EBOOK

This book provides a comprehensive introduction to the embryonic field of smart materials and structures, and also presents a state-of-the-art review of the sub-disciplines of the field. It informs readers of the technical challenges to the commercialisation of products incorporating these material technologies.