Damage Detection in Composite Materials Using Piezoelectric Elements PDF Download

Author: Xianghua Jian
Publisher:
ISBN:
Category :
Languages : en
Pages : 144

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Author: John E. Masters
Publisher: ASTM International
ISBN: 0803114745
Category : Ceramic-matrix composites
Languages : en
Pages : 280

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Book Description
A collection of 16 papers from an international symposium in San Antonio, November 1990, focusing on the necessary coordination between materials scientists, stress analysts, and non-destructive evaluation specialists, for successfully designing, building, certifying, and maintaining composite struc

Author: Abu Saeed Islam
Publisher:
ISBN:
Category :
Languages : en
Pages : 104

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Author: M H Ferri Aliabadi
Publisher: World Scientific
ISBN: 1786343940
Category : Technology & Engineering
Languages : en
Pages : 286

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Book Description
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.

Author: J. Bennett
Publisher:
ISBN:
Category :
Languages : en
Pages : 29

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Book Description
Damage detection in metallic and composite structural components is of particular importance in the damage tolerant assessment and the maintenance of aircraft structures. This report describes the use of piezoelectric film for sensing damage in a number of structural components. Three specimens were evaluated, viz.: (1) A rivetted lap joint; (2) A surface crack in an aluminium alloy; (3) An impact damaged composite laminate. The lap joint was chosen to be representative of a fuselage lap joint in modern, wide bodied aircraft. The joint contained multi-site damage repaired with a bonded doubler. Piezoelectric film was applied to the doubler and the underlying damage was detected. The second specimen was a conventional aluminum alloy with surface flaws emanating from a fastener hole. The last specimen was a graphite epoxy composite laminate with impact damage at two locations, i.e. multiple damages sites.

Author: Michelle DuBose Spiegel
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 39

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Book Description
Structural Health Monitoring (SHM) of bridges, buildings, aircrafts, and spacecraft using a network of sensors has gained popularity over recent years. In this thesis, the use of piezoelectric actuators and sensors is described for detecting damage in a composite panel. The composite panels are fabricated using the Vacuum Assisted Resin Transfer Molding (VARTM) process. The panels are cut into small coupons (254 mm x 25.4 mm) to test various properties of the composite. A piezoelectric actuator is surface mounted on the composite coupon to generate Lamb waves while a surface mounted piezoelectric sensor measures the response. Data is collected from an undamaged composite coupon, and then the process is repeated for a damaged coupon. The existing damage is quantified by comparing the response of the damaged and undamaged composite coupons.

Author: Seth Stovack Kessler
Publisher:
ISBN:
Category :
Languages : en
Pages : 200

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Book Description
(Cont.) These techniques have proven suitable for structural health monitoring applications since they can be applied with low power conformable sensors and can provide useful information about the state of a structure during operation. Piezoelectric patches could also be used as multipurpose sensors to test using a variety of methods such as modal analysis, Lamb wave, acoustic emission and strain based methods simultaneously by altering driving frequencies and sampling rates. Guidelines and recommendations drawn from this research are presented to assist in the design of a structural health monitoring system for a vehicle, and provides a detailed example of a SHM system architecture. These systems will be an important component in future designs of air and spacecraft to increase the feasibility of their missions.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The goal of the Phase 1 SBIR project described in this report was to develop a free vibration method for nondestructive evaluation of thick-walled composites. The governing principle of the free vibration method is that the frequency spectrum generated by a given object has the specificity of a fingerprint. Accordingly, if the boundary conditions, material properties, or geometry of the object are changed, some or all of the natural frequencies will change. Dramatic shifts have been observed in the natural vibrational frequencies of thin composite plates with the introduction of delaminations or other interply modifications; these observations provided the motivation for the present project in which the method was extended to thick plates. In our version of the free vibration method, the composite is excited into vibration by a single mechanical pulse and the vibrational behavior is monitored by removable surface- bonded piezoelectric polymer film elements. When bonded to the surface of the composite, the piezoelectric film acts like a strain gage, except that it requires no external power source and generates signals far greater than those of a traditional amplified strain gage. The great sensitivity of the piezoelectric polymer film sensors and the simplicity of the overall test configuration makes this version of the method attractive for in-plant or in-field nondestructive evaluation.

Author: Sazid Irfan Ahmed
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages :

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Book Description
Structural health monitoring of aerospace structures is becoming vital as lightweight composite materials are increasingly used in aero-structures. Composites have various types of failure modes, which make it even more important to identify fault or damage compared to isotropic materials. Therefore, on-site health monitoring is one of the most preferred methodologies for detecting internal crack or damage at its initial stage to enhance operating safety and reduce repair cost. Recently, piezoelectric transducers are on high demand for on-site health monitoring because of its high bandwidth sensitivity. They simultaneously perform as actuators and sensors and embedded in the structure for real time response indicative of the condition of the structure. Their characteristics show direct coupling between the electrical impedance and structural impedance. The electrical impedance or admittance changes according to modification in mass, stiffness or damping properties of the host body to which the transducer is attached. In this study, plain-weave textile composites are utilized to demonstrate the capability of piezoelectric transducer. The elastic properties of the composite are determined using the fiber tow properties that are derived via the Concentric Cylinder Assemblage micromechanics model. Finite element modeling is done in commercial software ANSYS APDL to observe electrical admittance variation around natural frequency of the entire structure to investigate structure condition. Delamination was studied at first but results show very small shift in frequency of the same mode number for healthy and defective structures along with same magnitude of admittance. This makes delamination detection via impedance approach not feasible. So, investigation was shifted to detection of intra-ply damage. Damage can be thought of as reduction of stiffness in the whole structure. Fair amount of shift in the modal frequency was observed with respect to damage level. Modal frequency of the structure decreased as well as admittance value lowered with damage increment within the body. Pre-preg manufacturing method is carried out to fabricate composite panel from which samples are cut for testing according to ASTM standards. Panel is fabricated in such a way that enabled 45-degree fiber orientation with respect to the longitudinal axis of specimen. This strategy is taken to easily incorporate damage into the specimen via tensile test. 45-degree fiber orientation will make it easier to create damage compared to the longitudinally aligned fiber sample. Piezo patch is attached to the body and sine sweep voltage is applied to actuate the transducer. It provided voltage drop across the resistor that denoted the coupling effect of the patch with the host structure. Electrical admittance plot expressed response to body deformation actuated by the piezoelectric transducer. Results from finite element modeling and experimentation both indicate shift of frequency value of specific mode for damaged beam from healthy status. Therefore, piezoelectric admittance technique is efficient in detecting damage or degradation within composite structure.

Author: Ahmad Hamdan Ariffin
Publisher: Springer Nature
ISBN: 9811962820
Category : Technology & Engineering
Languages : en
Pages : 262

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Book Description
The book focuses on the recent technology and advancement in structural integrity and monitoring systems in composite materials. Composites have been widely used in automotive, aerospace and wind turbine industries, therefore it is important to develop state of the art technology to monitor and manage the damage tolerance and durability. This book explores the challenge of a monitoring system in a composite and presents a real-time system which has advantages for damage detection, localization, assessment and life prediction compared to the Non-Destructive Testing (NDT). It will also present the modelling and prediction of failure in a composite material based on computational analysis of the characteristics and properties of the composite material based on fiber and matrix properties. This book will benefit lecturers, students, researchers, engineers and industrialist who are working in the civil, mechanical engineering, automotive, aerospace and wind turbine industries.