This highly comprehensive, introductory book explains the basics of structural health monitoring aspects of composite structures. This book serve as an all-in-one reference book in which the reader can receive a basic understanding of composite materials, manufacturing methods, the latest types of optical fiber sensors used for structural health monitoring of composite structures, and demonstrated applications of the use of fiber sensors in a variety of composite material structures. The content draws upon the authors’ and distinguished contributors’ extensive research/teaching and industrial experience to fully cover the structural health monitoring of composite materials using fiber optic sensing methods.

Structural health monitoring (SHM) is a relatively new and alternative way of non-destructive inspection (NDI). It is the process of implementing a damage detection and characterization strategy for composite structures. The basis of SHM is the application of permanent fixed sensors on a structure, combined with minimum manual intervention to monitor its structural integrity. These sensors detect changes to the material and/or geometric properties of a structural system, including changes to the boundary conditions and system connectivity, which adversely affect the system's performance.This book's primary focus is on the diagnostics element of SHM, namely damage detection in composite structures. The techniques covered include the use of Piezoelectric transducers for active and passive Ultrasonics guided waves and electromechanical impedance measurements, and fiber optic sensors for strain sensing. It also includes numerical modeling of wave propagation in composite structures. Contributed chapters written by leading researchers in the field describe each of these techniques, making it a key text for researchers and NDI practitioners as well as postgraduate students in a number of specialties including materials, aerospace, mechanical and computational engineering.

Structural health monitoring is the process of detecting damage to a structure, where damage can be characterized as changes to material/mechanical properties including but not limited to plastically deforming the material or the modification of connections. Fiber optic cables with fiber Bragg gratings have emerged as a reliable method of locally measuring strains within a structure. During the manufacturing of composite structures, the fiber optic cables can be embedded between lamina plies, allowing the ability to measure strain at discrete locations within the structure as opposed to electrical strain gauges, which must typically be applied to the surface only. The fiber optic sensors may be used to see if the local strain at the sensor location is beyond desired limits, or the array response may be mined to determine additional information about the loading applied to the structure. The work presented in this thesis is to present novel and potential applications of FBG sensors being used to assess the health of the structure. The first application is the dual application of the FBG sensor as a method to determine the strain around a bolt connection as well as the preload of the fastener using a single fiber optic sensor. The composite material around the bolted connections experience stress concentrations and are often the location of damage to the structure from operational cyclic loading over the lifetime of the structure. The degradation can occur more quickly if the fastener is insufficiently tight to transfer load properly. The second application is the ability to locate the impact location of a projectile with damaging and non-damaging energy. By locating and quantifying the damage, the sensor array provides the basis for a structural health monitoring system that has the potential to determine if the damage is extensive enough to replace, or if the part can be salvaged and retrofitted.

The use of fibre optic sensors in structural health monitoring has rapidly accelerated in recent years. By embedding fibre optic sensors in structures (e.g. buildings, bridges and pipelines) it is possible to obtain real time data on structural changes such as stress or strain. Engineers use monitoring data to detect deviations from a structure’s original design performance in order to optimise the operation, repair and maintenance of a structure over time. Fibre Optic Methods for Structural Health Monitoring is organised as a step-by-step guide to implementing a monitoring system and includes examples of common structures and their most-frequently monitored parameters. This book: presents a universal method for static structural health monitoring, using a technique with proven effectiveness in hundreds of applications worldwide; discusses a variety of different structures including buildings, bridges, dams, tunnels and pipelines; features case studies which describe common problems and offer solutions to those problems; provides advice on establishing mechanical parameters to monitor (including deformations, rotations and displacements) and on placing sensors to achieve monitoring objectives; identifies methods for interpreting data according to construction material and shows how to apply numerical concepts and formulae to data in order to inform decision making. Fibre Optic Methods for Structural Health Monitoring is an invaluable reference for practising engineers in the fields of civil, structural and geotechnical engineering. It will also be of interest to academics and undergraduate/graduate students studying civil and structural engineering.

Structural Health Monitoring of Aerospace Composite Structures offers a comprehensive review of established and promising technologies under development in the emerging area of structural health monitoring (SHM) of aerospace composite structures. Beginning with a description of the different types of composite damage, which differ fundamentally from the damage states encountered in metallic airframes, the book moves on to describe the SHM methods and sensors currently under consideration before considering application examples related to specific composites, SHM sensors, and detection methods. Expert author Victor Giurgiutiu closes with a valuable discussion of the advantages and limitations of various sensors and methods, helping you to make informed choices in your structure research and development. The first comprehensive review of one of the most ardent research areas in aerospace structures, providing breadth and detail to bring engineers and researchers up to speed on this rapidly developing field Covers the main classes of SHM sensors, including fiber optic sensors, piezoelectric wafer active sensors, electrical properties sensors and conventional resistance strain gauges, and considers their applications and limitation Includes details of active approaches, including acousto-ultrasonics, vibration, frequency transfer function, guided-wave tomography, phased arrays, and electrochemical impedance spectroscopy (ECIS), among other emerging methods

This book is organized around the various sensing techniques used to achieve structural health monitoring. Its main focus is on sensors, signal and data reduction methods and inverse techniques, which enable the identification of the physical parameters, affected by the presence of the damage, on which a diagnostic is established. Structural Health Monitoring is not oriented by the type of applications or linked to special classes of problems, but rather presents broader families of techniques: vibration and modal analysis; optical fibre sensing; acousto-ultrasonics, using piezoelectric transducers; and electric and electromagnetic techniques. Each chapter has been written by specialists in the subject area who possess a broad range of practical experience. The book will be accessible to students and those new to the field, but the exhaustive overview of present research and development, as well as the numerous references provided, also make it required reading for experienced researchers and engineers.

This book is the first to address the field of structurally integrated fiber optic sensors. Fiber optic sensors embedded within materials and systems are able to measure a variety of parameters (i.e. temperature, vibration, deformation, strain, etc.) that allows for real time non-destructive evaluation. Examples include the following: monitoring structural fatigue in aging aircraft or loads in bridge structures. In more advanced applications, fiber optic sensors control actuators that allow materials to adapt to their environment. This gives rise to the names, "smart," "intelligent," and/or "adaptive" materials or structures.Structural Monitoring with Fiber Optic Technology is the firs single author book on the new field of fiber optic structural sensing. As such it provides: coverage of the fundamentals of the technology, a coherent and systematic discussion on the most important aspects of the subject, a broad view of the subject, while retaining a degree of focus on those advances most significant in terms of their future potential, particularly in regard to broad implementation of the technology. The book provides an introduction to the relevant value to structural monitoring. It also highlights the advantages of fiber optic based sensors over conventional electrical measurement technology.The book richly illustrates the subject matter with 615 figures and provides many examples of fiber optic structural sensing, including a detailed overview of a number of major field site applications. Most of these large scale applications are drawn from the civil engineering community as they have been the first to strongly embrace fiber optic structural monitoring. This is especially true for bridges, where innovative new designs and the use of fiber reinforced polymer composite materials to replace steel represents a major advance that is expected to revolutionize the construction industry. Examples include new bridges, which are serving as testbeds for these new materials and are instrumented with arrays of fiber optic structural sensors. In one case, this state-of-the-art monitoring system permits engineers at a distant site to track the response of the bridge to traffic loads and keep an eye on the long term performance of the new materials. Fiber optic structural sensing technology is equally applicable to other industrial sectors, such as the aerospace and marine industries. Indeed, several examples of ships being instrumented with arrays of fiber optic sensors are also included. * The author directed one of the leading laboratories in the development of this technology and its application to civil engineering* Provides a strong, concise foundation in the basics of the technology* Includes many examples of the application of the technology, including many major field site case studies* Richly illustrated with 615 figures, many redrawn to make them easier to understand; also includes over 600 references* Written in a style designed to help the reader unfamiliar with fiber optic technology appreciate what can be accomplished with this new form of structural monitoring