+

WO1991019173A1 - Procede pour evaluer l'integrite structurale de structures composites - Google Patents

Procede pour evaluer l'integrite structurale de structures composites Download PDF

Info

Publication number
WO1991019173A1
WO1991019173A1 PCT/US1991/003857 US9103857W WO9119173A1 WO 1991019173 A1 WO1991019173 A1 WO 1991019173A1 US 9103857 W US9103857 W US 9103857W WO 9119173 A1 WO9119173 A1 WO 9119173A1
Authority
WO
WIPO (PCT)
Prior art keywords
composite
structural
frequency
stiffness
resonant
Prior art date
Application number
PCT/US1991/003857
Other languages
English (en)
Inventor
Gino A. Pinto
Richard E. Hayden
Charles S. Ventres
Original Assignee
Technology Integration And Development Group Incorporated
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Technology Integration And Development Group Incorporated filed Critical Technology Integration And Development Group Incorporated
Publication of WO1991019173A1 publication Critical patent/WO1991019173A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M7/00—Vibration-testing of structures; Shock-testing of structures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H13/00—Measuring resonant frequency
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M7/00—Vibration-testing of structures; Shock-testing of structures
    • G01M7/02—Vibration-testing by means of a shake table
    • G01M7/025—Measuring arrangements

Definitions

  • the present invention relates to a method and system fo -nondestructively evaluating the structural integrity of a mechanical component constructed from fiber composites, specifically for assessing the stiffness, strength and damping characteristics of a composite structure.
  • Nondestructive evaluation techniques provide a viable means for prediction of damage due to cyclic fatigue and environmental exposure of critical structures. Of particular interest is the degradation of strength which occurs throughout the life of the structure due to normal loading cycles. Unexpected damage such as impacts, delaminations, drastic environmental changes and loading may also occur throughout the life of a composite. It is vital to monitor the structural integrity of these critical structures during in-service operation and/or provide routine inspection while out of service.
  • the realized benefits of a composites monitoring system are: improved safety/reliability of structures, reduced cost in developing and maintaining structures, and a means to make critical decisions on the reliability of aging composites structures.
  • Composite materials are known to fail in a progressive manner through gradual deterioration (damage development) in the material caused by cyclic fatigue loading, impact loading and/or environmental exposure. Unlike metals, composite materials are inhomogeneous and quite often anisotropic. This results in a very complex fatigue process that reduces stiffness and strength while increasing the structural damping of the composite. Also, the stages of the damage development are highly dependent on the construction of the composite and the applied loading. The unique properties of composite structures make the process of predicting safe operating life quite difficult using conventional nondestructive evaluation techniques. These factors present a unique challenge for a versatile composites health monitoring system that effectively determines if any form of structural degradation has occurred, then concludes whether or not the component is suitable for service.
  • NDT nondestructive testing
  • Radiography Acoustic Emission
  • Thermal Methods Thermal Methods
  • Optical Methods Corona Discharge
  • Chemical Spectroscopy Because of the specialized equipment involved, it is not practical to use either radiography or chemical spectroscopy outside of the laboratory environment for continuous in-service monitoring.
  • Acoustic emission is a method where sensors are placed on a composite to "listen” to low level sonic or ultrasonic signals generated by damaged or degraded materials and is a candidate method for in-service monitoring.
  • the main problems with Acoustic emission is that the acoustic levels received at the sensor are dependent on the load applied to the structure. Acoustic interference from the operating environment (i.e., noise) may also be a problem for an in-service monitoring system relying on this technique.
  • Thermal methods rely on thermal imaging of stress generated heat fields within a composite. Cyclic loading induces heat generation in a material due to fatigue cracks or hysteresis within the matrix material. This method cannot be reliably used for continuous monitoring in many cases because of the sensitivity of the thermal sensors to other heat sources.
  • Fiber optic methods are gaining the most attention for in-service monitoring.
  • Light conducting fibers can be integrated into a composite structure during its manufacturing process. Fractures, cracks or delaminations are detected when these fibers are broken or damaged.
  • the main problems with fiber optic sensors are that this method cannot be implemented into existing composite structures and damage where no optical fibers exist cannot be detected.
  • the corona discharge method can be used for detecting voids within a material, where an electric field of high intensity is imposed in a dielectric composite material.
  • the void is detected by a minute pulse of current or by the radiation of electromagnetic wavelengths as a result of electron collision within the void walls.
  • the two main problems with this method are: (1) it is not practical to apply this method on a continuous in-service basis because of the risks and electromagnetic interference, and (2) it cannot be applied to conductive materials such as carbon (graphite) and metal fiber or metal matrix composites.
  • the present invention determines the composite's stiffness by tracking the frequency of a mechanical resonant mode(s) of a composite element and relating frequency changes directly to a change in stiffness.
  • the present invention also provides a supplemental nondestructive test by monitoring structural damping of these modes.
  • the composite integrity monitoring system of the present invention contains a database having predetermined (analytically or empirically) stiffness vs. strength relationships to infer a reduction in strength. Other environmental sensor information can also be used to compensate for any environmental frequency-influencing effects.
  • An observable feature resulting from degradation of composite structures is the reduction in the resonant frequencies of structural modes of vibration, -be they longitudinal, flexural, torsional, or shear modes.
  • This resonant frequency reduction is directly related to the reduction in the composite's stiffness (or increase in compliance).
  • the present invention obtains a quantitative change in stiffness of a structure by measuring a change in resonant frequency of the structural mode(s). Relationships can be empirically established between a composite structure's measurable stiffness reduction and a corresponding reduction in strength or increase in damage. An increase in damping is also an indication of an increase in damage.
  • the structural integrity monitoring system for composites tracks shifts in stiffness and damping, compensates for environmental effects, and assesses the structural integrity of the composite by virtue of empirically or analytically defined relationships and criteria for a particular composite structure.
  • the method in which the present invention tracks the dynamic stiffness (modulus) degradation of a composite element is by monitoring changes in the frequency of a structural resonant mode of vibration.
  • the fractional reduction in frequency, of a mode of vibration (bending or longitudinal). caused by a given modulus reduction is given by the following equation (valid for both beam and plate elements) :
  • f 0 and E 0 represent the initial resonant frequency of the mode being tracked and initial modulus of the element respectively.
  • the present invention gives two options for tracking the resonant modes of a composite element.
  • the first option is a passive sensing method where data is collected from a sensor or sensors and the time domain vibration history is transformed into the frequency domain spectrum via a process such as a Fast Fourier Transform (FFT).
  • FFT Fast Fourier Transform
  • the modal parameters of frequency and damping can then be determined through a spectrum analysis procedure.
  • the second option for the present invention's method is an active sensing/excitation method.
  • the actively excited composite structures are designed to use a sensor and actuator feedback system to cause a self-excited resonant mode of vibration; where a sensor (or sensors) and an actuator (or actuators) are used to simultaneously sense and excite a selected resonant mode.
  • the sensor senses a response (i.e. displacement, acceleration, strain) and provides a signal (proportional to the response) that is amplified and fed back to the actuator to produce an excitation force or bending moment in the same structure, thus causing a self-excited mechanical resonance.
  • a frequency counting device is used to track the frequency of the resonant mode while a voltage sensing device is used to infer structural damping within the composite.
  • the measurements can be made by using integral sensors or actuators attached to or embedded in the composite structure at pre-selected locations during or after the manufacturing stage. This method is therefore used to track the mechanical resonant frequencies of the composite's structural modes and also provide a measurement for inherent damping within the structure.
  • Both passive and active experimental modal techniques can be selected to measure stiffness degradation and inherent structural damping. Once damage relationships have been established, the measured stiffness properties can be related to degradation in structural integrity (i.e. strength loss or reduced life expectancy). These methods will then provide the means for a system to nondestructively predict the degradation of the composite's strength or its life expectancy for in- service monitoring or periodic inspection.
  • the passive modal methods offer the opportunity to use existing broadband excitation, provided by the structure's operating environment, to excite all resonant modes.
  • the actively excited structures offer the benefits of "self-excitation" of selected resonant modes, real-time tracking of resonant modes, simplified signal processing, and simplified system architecture.
  • the premise for the system of the present invention utilizing these modal methods is that the stages of damage development are well characterized for the composite structure under known loading conditions, and suitable damage relationships can be found empirically.
  • This system can then utilize these known statistical strength degradation/stiffness reduction and damage/damping relationships in order to determine structural integrity. Stiffness changes are detected through measurement of changes in resonant behavior of the structure and strength loss is inferred through statistical relationships established after a particular material is developed and tested. These vibration measurements can be easily performed in an on-board in-service system or used as a periodic inspection technique for any type of structure or component.
  • the system is capable of returning a health status report, giving probability of composite failure due to the measured stiffness reduction and increase in damping.
  • Yet another objective of the present invention is to provide a system and method for sensing and excitation of several resonant modes for added assurance and reliability of predictions made on structural integrity.
  • the method and system for assessing structural integrity of composite structures have the additional advantages that a quantitative measurement of the material stiffness and damping properties coupled with redundant sensing and statistical techniques can be used to ensure a high degree of reliability and a low false-alarm rate; it can be used to monitor any stiffness critical component; it can be used to monitor mass changes (or density changes) in structural components; it can be used for in-service condition monitoring of aircraft structural components; it can be implemented into an on-board system for long-term monitoring of manned and unmanned spacecraft and orbiting structures; it can be used to monitor the structural integrity of helicopter rotor blades and advanced turboprop blades; it can be used for engine structure monitoring and mechanical fault isolation; it can be used for on-board monitoring of flutter in aircraft components; and it can be used for any ground based inspection of composite structures.
  • Figure 1 illustrates an example of a generic composite structural integrity monitoring system's functions.
  • Figure 2 gives an example of a system utilizing the passive sensing method for monitoring of structural integrity.
  • Figure 3 gives an example of distributed sensing and actuation applied to the active feedback method for modal excitation of a composite structure.
  • Figure 4 gives an example of single point excitation/sensing applied to the active feedback method for modal excitation of a composite structure.
  • Figure 1 illustrates an example of a generic composites-health monitoring system that can incorporate the passive modal tracking method or the active modal excitation/tracking method.
  • the composite structure 10 is outfitted with sensors 12, for a passive approach, or sensors 12 and actuators 14 for an active approach.
  • the sensors are used to sense strain or motion and may be non-contacting types (e.g., laser vibrometer or optical sensors), surface mounted or embedded types.
  • Environmental sensors 16 can be placed near or on the structure 10 if it is necessary for compensation of environmental effects.
  • Signal conditioning 18 such as pre-amplification, powering, signal summation, signal differencing, amplification, filtering or phase control is performed on sensor and actuator signals if necessary.
  • the sensor signal(s) 12, conditioned or otherwise, are then passed on to the signal analyzer 22.
  • the function of the signal analyzer 22 is to resolve the frequency (or frequencies) of a distinct mode (or modes) of resonance and/or resolve the structural damping of the composite structure 10.
  • the structural integrity model 24 is an algorithm used to infer the structural degradation of a composite.
  • the structural integrity model 24 takes, as an input, either the changes in resonant frequency of a structural mode, the structural damping, or both. It can also compensate for changes in frequency and damping given by the environmental model 20, if necessary. Since the system of Fig. 1 can reliably track the stiffness reduction of the composite structure 10 during its life duration, then the strength reduction may be inferred through relationships that correctly reflect stiffness vs. strength behavior for that particular composite.
  • the composite structures integrity monitoring system of Figure 1 is designed to accept environmental sensor 16 data (e.g., from strain sensors and temperature sensors), provide signal conditioning 18 if necessary, and correct for the frequency- influencing and damping-influencing effects of the environment using the environmental model 20.
  • the environmental model 20 is an algorithm used to infer the effect of these environmental influences on the structural dynamic behavior of the composite structure 10 (i.e., stiffness and damping).
  • a full coverage composites structural life integrity system may need to make various measurements (such as -frequency tracking of modes, amplitude monitoring, damping monitoring, temperature and strain monitoring) that are incorporated into algorithms to track the life consumption of critical parts. Also, redundant sensing must be considered, and statistical system identification techniques developed to ensure a high degree of reliability and a low false-alarm rate. Selective weighing of these different methods and factors will result in the ability to prognosis failure and to thus schedule on-condition maintenance for parts replacement near the end of their useful life.
  • the composite structure 10 is outfitted with a sensor 12 or group of sensors.
  • the distributed sensor elements can be bonded, embedded or noncontact that give an output signal in response to a strain or motion of the composite structure.
  • sensors 12 are strain sensors, accelerometers, velometers, or any type of displacement sensors. Filtering of the sensor signal(s) can be performed, if necessary by the signal conditioner 18.
  • the signal analyzer 22 the time history signal is transformed from the time domain to the frequency domain via a processing method such as a Fourier Transform.
  • the frequency of any selected resonant mode of vibration can be identified by a peak response in the Fourier Transform (i.e., peak amplitude response).
  • Near real ⁇ time performance for in-service composites monitoring may be accomplished by utilizing fast analog-to- digital (A/D) converters to capture the time history output of the sensors, followed by digital spectrum analysis.
  • A/D analog-to- digital
  • the damping ratio may be resolved by using a standard technique called the half-power bandwidth method.
  • the results of frequency shift and/or damping can then be passed to the structural integrity model 24 and environmentally compensated, displayed or stored as illustrated in Figure 1.
  • Figure 3 illustrates an example of a composites monitoring system that utilizes the active frequency tracking technique.
  • the composite structural element 10 is outfitted with a sensor or sensors 12, that can be a strain sensor, accelerometer, velometer, displacement sensor, non-contact optical sensor or any other vibration sensor.
  • the signal from the sensor is passed to the signal conditioning circuit 18.
  • the signal conditioning circuit 18 provides rate feedback (phase lag between the sensor inpu (s) 12 and the actuator output(s) 14) to ensure self sustained oscillation of the structure.
  • the signal conditioning circuit 18 can contain filtering capabilities 28 such as a low-pass, high-pass or band-pass filter and/or phase control of the signal such as an inverting amplifier.
  • the filtered signal is then passed to an amplification circuit 30, that amplifies the signal and may have the additional feature of providing additional phase control.
  • the signal is then passed on to the actuator 14, that can be a piezoelectric pad or shaker, electrodynamic shaker, acoustic speaker or any other strain or vibration inducing device.
  • This simple feedback circuit is sufficient to cause the element to which the actuator and sensor are bonded to 10, to achieve a state of self induced mechanical resonance of a selected mode. Mode control can be accomplished either through spatial distribution of the sensor(s) 12, actuator(s) 14, or both, selective band-pass filtering, or any combination thereof.
  • a frequency counting device 22, is used to track the resonant frequency of the composite element 10. The results of frequency shift and/or damping can then be passed to the structural integrity model 24 and environmentally compensated, displayed or stored as illustrated in Figure 1.
  • Figure 4 illustrates another example of a composites monitoring system that utilizes the active frequency tracking technique.
  • the composite structural element 10 is outfitted with a device that can function as an actuator and sensor 32, such as an impedance-head shaker. This device can produce an output sensor signal 12, that is proportional to acceleration, velocity, displacement, strain, or force.
  • the signal from the sensor is passed to a signal conditioning circuit 18.
  • the signal conditioning circuit 18 provides rate feedback (phase lag between the sensor input 12, and the actuator output 14) to ensure self sustained oscillation of the structure.
  • the signal conditioning circuit 18 can contain filtering capabilities 28 such as a low-pass, high-pass or band-pass filter and/or phase control of the signal such as an inverting amplifier.
  • the filtered signal is then passed to an amplification circuit 30, that amplifies the signal and may have the additional feature of providing additional phase control.
  • the signal is then passed on to the actuator 14, that can be piezoelectric pad or shaker, electrodynamic shaker or any other strain or vibration inducing device.
  • This simple feedback circuit is sufficient to cause the element to which the sensor/ actuator device 32, bonded to 10, to achieve a state of self induced mechanical resonance of a selected mode. Mode control can be accomplished through selective band-pass filtering.
  • a frequency counting device 22 is used to track the resonant frequency of the composite element 10. The results of frequency shift and/or damping can then be passed to the structural integrity model 24 and environmentally compensated, displayed or stored as illustrated in Figure 1.
  • Tracking the resonant frequency of only one mode will suffice to get an assessment of the reduced distributed stiffness. Tracking the frequencies of more than one mode may give added redundancy and the ability to detect localized damage. This can be accomplished by having a sequence of signal conditioning steps that cause the structure to shift from one self-excited mode to another.
  • a frequency counter can be used to track frequency shifting of a single self-excited mode thus eliminating the need to perform an indirect transform of a captured time history signal into the frequency domain (i.e. through FFT processing). This allows for changes in resonant frequencies to be tracked in real-time (a desirable attribute for in-service monitoring).
  • the active excitation methods of Figures 3 and 4 provide the opportunity to measure the change in structural damping by measuring the voltages produced by the sensor pad and applied to the driver pad.
  • the ratio of the measured sensor voltage to the applied driver voltage is inversely proportional to the structural damping within the composite.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)

Abstract

Procédé et système pour une évaluation non destructive de l'intégrité structurale de structures composites (10). Le procédé de la présente invention consiste à faire des mesures quantitatives périodiques ou en continu des variations de rigidité structurale et d'amortissement structural et à établir un lien entre ces variations et la dégradation effective de l'intégrité structurale (24) de la structure composite (10). Le système de surveillance des structures composites met en ÷uvre des méthodes de vibrations (12, 14) pour surveiller les variations des caractéristiques de rigidité et d'amortissement de la structure (10) examinée. La poursuite en fréquence (22) de modes résonants structuraux de vibration ainsi que la compensation d'effets environnementaux (16) permettent de déterminer facilement des variations de rigidité de la structure composite (10). Le système flexible permet l'introduction d'algorithmes décrivant n'importe quelle caractéristique de tenue à la fatigue ou à la détérioration de la structure composite.
PCT/US1991/003857 1990-06-01 1991-05-31 Procede pour evaluer l'integrite structurale de structures composites WO1991019173A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US53226590A 1990-06-01 1990-06-01
US532,265 1990-06-01

Publications (1)

Publication Number Publication Date
WO1991019173A1 true WO1991019173A1 (fr) 1991-12-12

Family

ID=24121050

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1991/003857 WO1991019173A1 (fr) 1990-06-01 1991-05-31 Procede pour evaluer l'integrite structurale de structures composites

Country Status (2)

Country Link
AU (1) AU8508491A (fr)
WO (1) WO1991019173A1 (fr)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997004291A1 (fr) * 1995-07-14 1997-02-06 Brent Felix Jury Procede et appareil permettant d'effectuer des essais de controle et de relaxation des tensions internes
WO2002016926A1 (fr) * 2000-08-23 2002-02-28 Mecon Limited Surveillance de structures
NL1017304C2 (nl) * 2001-02-07 2002-08-08 Ten Cate Nicolon B V Werkwijze en inrichting voor het bepalen van waarden voor de stijfheid en demping van oppervlakken.
EP1659400A1 (fr) * 2004-11-22 2006-05-24 Gamesa Desarrollos Aeronauticos, S.A. Réseaux de transducteur piezoéléctrique pour la surveillance de l'état des structures
ES2276621A1 (es) * 2005-12-09 2007-06-16 Gamesa Desarrollos Aeronauticos S.A. Dispositivos activo-pasivos para control de vibraciones y deteccion de defectos.
US7555951B2 (en) 2006-05-24 2009-07-07 Honeywell International Inc. Determination of remaining useful life of gas turbine blade
EP1764602A3 (fr) * 2005-09-16 2010-08-25 Doosan Babcock Energy Limited Dispositif d'analyse de vibrations
FR2980010A1 (fr) * 2011-09-13 2013-03-15 Thibault Gouache Procede de mesure des proprietes dynamiques d'une structure mecanique
ITUB20151812A1 (it) * 2015-07-02 2017-01-02 Univ Degli Studi Di Trieste Dispositivo di rilevazione dell'integrita strutturale di un oggetto campione
ITUB20153476A1 (it) * 2015-09-08 2017-03-08 Univ Degli Studi Di Trieste Metodo di rilevazione sperimentale del modulo elastico di oggetti, campioni, o semilavorati in materiale vario
WO2017141207A2 (fr) 2016-02-19 2017-08-24 Mahavadi Management And Technology Services Gmbh Systèmes et procédé de détection de modifications dans la santé structurale d'un panneau composite
CN113358308A (zh) * 2021-06-03 2021-09-07 哈尔滨工业大学 基于有限测点和全局模态的组合结构横向位移确定方法
FR3110274A1 (fr) * 2020-05-13 2021-11-19 Promic dispositif mécanique complet d'oscillations forcées et résonance selon les principes technologiques de la réalité augmentée.
US20220090972A1 (en) * 2019-06-03 2022-03-24 Promocion Y Desarrollo De Sistemas Automaticos S.L.U. Method of measurement of the acting forces in a structure and/or the temperature in the structure
CN114894361A (zh) * 2022-05-09 2022-08-12 中北大学 基于跨点频响阻尼特性的金属构件残余应力定量检测方法
FR3136857A1 (fr) * 2022-06-16 2023-12-22 Safran Ceramics Procede de mesure du module de rigidite axial d’une eprouvette en materiau composite a matrice ceramique
CN118777425A (zh) * 2024-09-12 2024-10-15 中国民用航空飞行学院 一种功能梯度材料制备过程中的质量检测方法
CN118777426A (zh) * 2024-09-12 2024-10-15 中国民用航空飞行学院 一种功能梯度材料制备过程中的质量检测系统

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112255121B (zh) * 2020-12-23 2021-05-14 天津航天瑞莱科技有限公司 基于Matlab叶片疲劳极限评估方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1943619A (en) * 1927-01-10 1934-01-16 Mudge William Alvin Method and apparatus for testing materials
US3319460A (en) * 1963-06-05 1967-05-16 Electronique Appliquee Device for determining the modulus of young of visco-elastic materials
US3513690A (en) * 1967-08-18 1970-05-26 Univ Washington Method and apparatus for non-destructive testing of beams
US3620069A (en) * 1969-01-24 1971-11-16 Nasa Method and apparatus for measuring the damping characteristics of a structure
US4596142A (en) * 1983-07-08 1986-06-24 United Kingdom Atomic Energy Authority Ultrasonic resonance for detecting changes in elastic properties
US4901575A (en) * 1988-11-30 1990-02-20 Gp Taurio, Inc. Methods and apparatus for monitoring structural members subject to transient loads
US4944185A (en) * 1989-01-17 1990-07-31 Westinghouse Electric Corp. System and method for qualitatively and nondestructively inspecting adhesive joints and other materials

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1943619A (en) * 1927-01-10 1934-01-16 Mudge William Alvin Method and apparatus for testing materials
US3319460A (en) * 1963-06-05 1967-05-16 Electronique Appliquee Device for determining the modulus of young of visco-elastic materials
US3513690A (en) * 1967-08-18 1970-05-26 Univ Washington Method and apparatus for non-destructive testing of beams
US3620069A (en) * 1969-01-24 1971-11-16 Nasa Method and apparatus for measuring the damping characteristics of a structure
US4596142A (en) * 1983-07-08 1986-06-24 United Kingdom Atomic Energy Authority Ultrasonic resonance for detecting changes in elastic properties
US4901575A (en) * 1988-11-30 1990-02-20 Gp Taurio, Inc. Methods and apparatus for monitoring structural members subject to transient loads
US4944185A (en) * 1989-01-17 1990-07-31 Westinghouse Electric Corp. System and method for qualitatively and nondestructively inspecting adhesive joints and other materials

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997004291A1 (fr) * 1995-07-14 1997-02-06 Brent Felix Jury Procede et appareil permettant d'effectuer des essais de controle et de relaxation des tensions internes
US6026687A (en) * 1995-07-14 2000-02-22 Jury; Brent Felix Stress testing and relieving method and apparatus
WO2002016926A1 (fr) * 2000-08-23 2002-02-28 Mecon Limited Surveillance de structures
CN100406869C (zh) * 2001-02-07 2008-07-30 腾凯特塞奥隆公司 确定表面刚度和阻尼值的设备
WO2002063267A1 (fr) * 2001-02-07 2002-08-15 Ten Cate Nicolon B.V. Procede et dispositif pour determiner les valeurs de rigidite et d'amortissement de surfaces
US6962073B2 (en) 2001-02-07 2005-11-08 Ten Cate Thiolon B.V. Method and device for determining the values of stiffness and dampening of surfaces
NL1017304C2 (nl) * 2001-02-07 2002-08-08 Ten Cate Nicolon B V Werkwijze en inrichting voor het bepalen van waarden voor de stijfheid en demping van oppervlakken.
EP1659400A1 (fr) * 2004-11-22 2006-05-24 Gamesa Desarrollos Aeronauticos, S.A. Réseaux de transducteur piezoéléctrique pour la surveillance de l'état des structures
EP1764602A3 (fr) * 2005-09-16 2010-08-25 Doosan Babcock Energy Limited Dispositif d'analyse de vibrations
ES2276621A1 (es) * 2005-12-09 2007-06-16 Gamesa Desarrollos Aeronauticos S.A. Dispositivos activo-pasivos para control de vibraciones y deteccion de defectos.
ES2276621B1 (es) * 2005-12-09 2008-06-01 Gamesa Desarrollos Aeronauticos S.A. Dispositivos activo-pasivos para control de vibraciones y deteccion de defectos.
US7555951B2 (en) 2006-05-24 2009-07-07 Honeywell International Inc. Determination of remaining useful life of gas turbine blade
FR2980010A1 (fr) * 2011-09-13 2013-03-15 Thibault Gouache Procede de mesure des proprietes dynamiques d'une structure mecanique
WO2013037880A1 (fr) * 2011-09-13 2013-03-21 Gouache Thibault Procédé de mesure des propriétés dynamiques d'une structure mécanique
ITUB20151812A1 (it) * 2015-07-02 2017-01-02 Univ Degli Studi Di Trieste Dispositivo di rilevazione dell'integrita strutturale di un oggetto campione
EP3112836A2 (fr) 2015-07-02 2017-01-04 Universita Degli Studi di Trieste Dispositif et procédé pour détecter l'intégrité structurelle d'un échantillon d'objet
ITUB20153476A1 (it) * 2015-09-08 2017-03-08 Univ Degli Studi Di Trieste Metodo di rilevazione sperimentale del modulo elastico di oggetti, campioni, o semilavorati in materiale vario
EP3141305A1 (fr) 2015-09-08 2017-03-15 Universita Degli Studi di Trieste Méthode expérimentale de détermination du module d'élasticité d'objects, échantillons ou produits semi-finis de matériaux différents
WO2017141207A2 (fr) 2016-02-19 2017-08-24 Mahavadi Management And Technology Services Gmbh Systèmes et procédé de détection de modifications dans la santé structurale d'un panneau composite
US20220090972A1 (en) * 2019-06-03 2022-03-24 Promocion Y Desarrollo De Sistemas Automaticos S.L.U. Method of measurement of the acting forces in a structure and/or the temperature in the structure
US12025515B2 (en) * 2019-06-03 2024-07-02 Promocion Y Desarrollo De Sistemas Automaticos S.L.U. Method of measurement of the acting forces in a structure and/or the temperature in the structure
FR3110274A1 (fr) * 2020-05-13 2021-11-19 Promic dispositif mécanique complet d'oscillations forcées et résonance selon les principes technologiques de la réalité augmentée.
CN113358308A (zh) * 2021-06-03 2021-09-07 哈尔滨工业大学 基于有限测点和全局模态的组合结构横向位移确定方法
CN113358308B (zh) * 2021-06-03 2022-10-25 哈尔滨工业大学 基于有限测点和全局模态的组合结构横向位移确定方法
CN114894361A (zh) * 2022-05-09 2022-08-12 中北大学 基于跨点频响阻尼特性的金属构件残余应力定量检测方法
FR3136857A1 (fr) * 2022-06-16 2023-12-22 Safran Ceramics Procede de mesure du module de rigidite axial d’une eprouvette en materiau composite a matrice ceramique
CN118777425A (zh) * 2024-09-12 2024-10-15 中国民用航空飞行学院 一种功能梯度材料制备过程中的质量检测方法
CN118777426A (zh) * 2024-09-12 2024-10-15 中国民用航空飞行学院 一种功能梯度材料制备过程中的质量检测系统
CN118777426B (zh) * 2024-09-12 2024-11-22 中国民用航空飞行学院 一种功能梯度材料制备过程中的质量检测系统
CN118777425B (zh) * 2024-09-12 2024-11-29 中国民用航空飞行学院 一种功能梯度材料制备过程中的质量检测方法

Also Published As

Publication number Publication date
AU8508491A (en) 1991-12-31

Similar Documents

Publication Publication Date Title
Kawiecki Modal damping measurement for damage detection
WO1991019173A1 (fr) Procede pour evaluer l'integrite structurale de structures composites
Park et al. Impedance‐Based Structural Health Monitoring
Park et al. Impedance-based health monitoring of civil structural components
Chaudhry et al. Local-area health monitoring of aircraft via piezoelectric actuator/sensor patches
Park et al. Impedance-based structural health monitoring for temperature varying applications
US6192758B1 (en) Structure safety inspection
Huynh et al. Impedance‐based cable force monitoring in tendon‐anchorage using portable PZT‐interface technique
US7487059B2 (en) Transducer health diagnostics for structural health monitoring (SHM) systems
US7623974B2 (en) System and method for detecting onset of structural failure
US20070006652A1 (en) Load measuring sensor and method
EP2333537B1 (fr) Décomposition de mode des ondes sonores utilisant une correspondance d'amplitude
Kessler et al. Design of a piezoelectric-based structural health monitoring system for damage detection in composite materials
Lewis et al. Smart sensors and system health management tools for avionics and mechanical systems
Mandache et al. Considerations on structural health monitoring reliability
Ghoshal et al. Damage detection testing on a helicopter flexbeam
EP4006517A1 (fr) Procédé permettant de détecter et de localiser des fissures dans une structure physique au moyen d'une technique d'impédance électromécanique
Inman et al. Simultaneous active damping and health monitoring of aircraft panels
US20180217014A1 (en) Multifunctional piezoelectric load sensor assembly
Park et al. Removing effects of temperature changes from piezoelectric impedance-based qualitative health monitoring
Mangalgiri et al. Structural health monitoring
Kessler et al. In-situ sensor-based damage detection of composite materials for structural health monitoring
Kim A smart health monitoring system with application to welded structures using piezoceramic and fiber optic transducers
Schultz et al. Full-spectrum interrogation of fiber Bragg grating sensors for dynamic measurements incomposite laminates
Dunne et al. Recent advances in active damage interrogation

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU CA JP KR NO

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU NL SE

NENP Non-entry into the national phase

Ref country code: CA

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载