&lt;title&gt;High-frequency impedance analysis for NDE of complex precision parts&lt;/title&gt;

Lalande, F.; Rogers, Craig A.; Childs, Brian W.; Chaudhry, Zaffir

doi:10.1117/12.239026

Cited by 30 publications

(18 citation statements)

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“…The natural frequency ofthe beam in bending mode has well-known solution for the first several modes, which is fr/ (5) 2ic pA where IT 5 the natural frequency of the bending mode, 3,. is the weighted frequency for the each mode and I , A are the area moment of inertia and area of the cross section, respectively, of the beam. This equation can be rewritten to account for the temperature dependency ofthe material properties by incorporating equations (2-4) as follows:…”

Section: Variation In Structural Dynamic Characteristics Caused By Chmentioning

confidence: 99%

<title>Removing effects of temperature changes from piezoelectric impedance-based qualitative health monitoring</title>

Park

Kabeya

Cudney

et al. 1998

Smart Structures and Materials 1998: Sensory Phenomena and Measurement Instrumentation for Smart Structures and Materials

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A high frequency NDE technique has been under investigation at the Center for Intelligent Material Systems and Structures (CJMSS). Physical changes in the structure cause changes in the mechanical impedance. Due to the electromechanical coupling in piezoelectric materials, this change in structural mechanical impedance causes a change in the electrical impedance of the piezoelectric sensor. Hence, by monitoring the electrical impedance and comparing this to a baseline impedance measurement, we can determine when structural damage has either occurred or is imminent. However, there are still basic research issues that need thorough investigation before full-scale development and commercialization can take place. Included in these is the effect of temperature on this impedance based NDE technique. Since piezoelectric materials exhibit strong temperature dependency and change in temperature results in marked changes in the structural dynamic response, any variation that is associated with a change in temperature may be confused as damage. In this paper we analyze temperature effects on the electrical impedance of piezoelectric materials and the structures. We have used an empirical approach due to the complexity of the thermo-electrical-mechanical constitutive models for piezoelectric materials. Through the experimental investigations, it was found that a change in temperature modifies both the magnitude and phase of the electrical impedance of the piezoelectric sensors. A computer algorithm was developed which incorporates temperature compensation into our health monitoring applications. This compensation technique minimizes the effect of temperatures on the electrical impedance of piezoelectric sensors bonded on the structure, in the range from 80 to 1 60 degrees Fahrenheit. In this paper, we show how it is applied successfully to a bolted pipe structure.

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Section: Variation In Structural Dynamic Characteristics Caused By Chmentioning

confidence: 99%

<title>Removing effects of temperature changes from piezoelectric impedance-based qualitative health monitoring</title>

Park

Kabeya

Cudney

et al. 1998

Smart Structures and Materials 1998: Sensory Phenomena and Measurement Instrumentation for Smart Structures and Materials

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“…Experimental implementation of the impedance-based structural health monitoring technique has been successfully conducted on several complex structures: a four bay space truss (Sun et al 1995), an aircraft structure , complex precision parts (Lalande et al 1996), temperature varying applications (Park et al1999), a spotwelded structural joints (Giurgiutiu et al 1999), civil structural components (Park et al, 2000), a reinforced concrete bridge (Soh et al 2000) and civil pipelines (Park et al 2001a). …”

Section: Structurementioning

confidence: 99%

System for Structural Health Monitoring based on piezoelectric sensors/actuators

Neto

Steffen

Rade

et al. 2011

XI Brazilian Power Electronics Conference

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The Structural Health Monitoring -SHM method based on electrical impedance has been developed as a promising tool for structure failure identification in real time and is considered a novel nondestructive evaluation method. The piezoelectric -PZT impedance can be directly associated to the structure's mechanical impedance where de PZT is bonded. Assuming that the mechanical PZT properties do not change over the monitoring time, the electrical PZT impedance can be used for monitoring structural health. The use of each PZT as both sensor and actuator reduces the total number of sensor and wires connecting them to the switching circuit. The technique consists in obtaining Frequency Response Functions -FRF, with the related signal modification, periodically. Modifications in the FRF of each PZT would indicate structural changes and, therefore, a possible failure. The required number of PZTs will be determined by the dimensions of the monitored structure and the precision required for locating a possible failure. To obtain the FRF of the entire monitored structure it is used a switching and signal conditioning system that continuously activate and deactivate each PZT. This paper proposes a solid state, low power, small sized and low signal distortion switching system. The system is quite modular and each module can manage 16 PZTs. It is possible to expand the sensing net by interconnecting a non limited number of modules. Descriptions of the working principles, circuits used and experimental results are presented.

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“…Experimental i mplementation of the piezoimpedance method has been successfully conducted on several complex structures; a quarter model of steel girder bridge [3], a composite reinforced concrete wall [3], a massive cylinder header [4], a high precision gear [5], a space structure [5] and an aircraft [6]. For above real structures, a spring-mass model as shown in Fig.2 has been adopted.…”

Section: Previous Studies and Problemsmentioning

confidence: 99%

Structural Health Monitoring by Piezo-Impedance Method

Miyashita¹,

Abé²,

Fujino³

2002

IABSE Symposium, Melbourne 2002: Towards a Better Built Environment - Innovation, Sustainability, Information Technology

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This paper presents a fundamental study of a structural health monitoring technique called the piezo-impedance method, which utilizes an electromechanical property of piezoceramics. For a thin beam with tensile force, an analytical model of the piezo-impedance method is formulated based on the wave propagation theory. Also, a tensile force identification method in a thin beam combined with optimization techniques is proposed. An experiment is performed with small test pieces of a beam to investigate the validity of the proposed method and it is found that analytical results are in good agreement with experimental measurement results and that the tensile force is identified with accuracy. By using the proposed method, it is possible to identify absolute value of the tensile force in a beam from only one measurement.

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<title>High-frequency impedance analysis for NDE of complex precision parts</title>

Cited by 30 publications

References 0 publications

<title>Removing effects of temperature changes from piezoelectric impedance-based qualitative health monitoring</title>

<title>Removing effects of temperature changes from piezoelectric impedance-based qualitative health monitoring</title>

System for Structural Health Monitoring based on piezoelectric sensors/actuators

Structural Health Monitoring by Piezo-Impedance Method

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