An Enhanced Experimental Facility for Durability and Performance Characterisation of Piezoelectric Transducers for Structural Health Monitoring

2013 ◽  
Vol 558 ◽  
pp. 374-385
Author(s):  
George Jung ◽  
Stephen van der Velden ◽  
Kelly Tsoi ◽  
Nik Rajic
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Piezoelectric Transducers ◽  
Peak Strain ◽  
Experimental Facility ◽  
Electromechanical Impedance ◽  
Structural Health ◽  
Mechanical Durability ◽  
System Verification

With any structural health monitoring (SHM) system, verification of the health of the sensing elements is essential in ensuring confidence in the measurements furnished by the system. In particular, SHM systems utilised for structural hot spot monitoring applications will conceivably require transducers to operate reliably after sustained exposure to severe mechanical loading. Consequently, a good understanding of the long term mechanical durability performance of structurally integrated piezoelectric transducers is vital when designing and implementing robust SHM systems. An experimental facility has been developed at the Australian Defence Science and Technology Organisation (DSTO) capable of performing an autonomous long-term mechanical durability test on piezoceramic transducers. The Autonomous Mechanical Durability Experimentation and Analysis System (AMeDEAS) incorporates a general purpose data acquisition program controlling up to three 8-channel relay multiplexers and two instruments. AMeDEAS is highly flexible, allowing user-specified channel configurations and automatic interrogation of selected instruments. The system also interfaces with the uni-axial mechanical testing machine to provide control of the load sequence allowing transducer elements to be interrogated under stable load-free conditions after being subject to a predefined loading regime. AMeDEAS was used to investigate the fatigue characteristics of a low-profile layered piezoceramic transducer package developed by DSTO. A total of 16 transducers were tested under tension-dominated cyclic loading with peak-to-peak strain amplitude increasing from 400 με to a maximum of 3000 με, with periodic acoustic transduction efficiency and electromechanical impedance measurements taken throughout the test. This paper details the AMeDEAS and includes preliminary results which confirm the efficacy of the new facility.

Validation of Impedance-Based Structural Health Monitoring in a Simulated Biomedical Implant System

2018 ◽  
Author(s):  
Robert I. Ponder ◽  
Mohsen Safaei ◽  
Steven R. Anton
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Orthopedic Implants ◽  
The United States ◽  
The State ◽  
Piezoelectric Transducers ◽  
Bone Implant ◽  
Electromechanical Impedance ◽  
Structural Health ◽  
Number Of Patients

Total Knee Replacement (TKR) is an important and in-demand procedure for the aging population of the United States. In recent decades, the number of TKR procedures performed has shown an increase. This pattern is expected to continue in the coming decades. Despite medical advances in orthopedic surgery, a high number of patients, approximately 20%, are dissatisfied with their procedure outcomes. Common causes that are suggested for this dissatisfaction include loosening of the implant components as well as infection. To eliminate loosening as a cause, it is necessary to determine the state of the implant both intra- and post-operatively. Previous research has focused on passively sensing the compartmental loads between the femoral and tibial components. Common methods include using strain gauges or even piezoelectric transducers to measure force. An alternative to this is to perform real-time structural health monitoring (SHM) of the implant to determine changes in the state of the system. A commonly investigated method of SHM, referred to as the electromechanical impedance (EMI) method, involves using the coupled electromechanical properties of piezoelectric transducers to measure the host structure’s condition. The EMI method has already shown promise in aerospace and infrastructure applications, but has seen limited testing for use in the biomechanical field. This work is intended to validate the EMI method for use in detecting damage in cemented bone-implant interfaces, with TKR being used as a case study to specify certain experimental parameters. An experimental setup which represents the various material layers found in a bone-implant interface is created with various damage conditions to determine the ability for a piezoelectric sensor to detect and quantify the change in material state. The objective of this work is to provide validation as well as a foundation on which additional work in SHM of orthopedic implants and structures can be performed.

Structural health monitoring of rotary aerospace structures based on electromechanical impedance of integrated piezoelectric transducers

2018 ◽  
Vol 29 (9) ◽  
pp. 1799-1817 ◽  
Author(s):  
Hamidreza Hoshyarmanesh ◽  
Ali Abbasi
Keyword(s):  
Structural Health Monitoring ◽  
Frequency Shift ◽  
Health Monitoring ◽  
Rotational Speed ◽  
Mechanical Impedance ◽  
Impedance Spectrum ◽  
Piezoelectric Transducers ◽  
Aerospace Structures ◽  
Electromechanical Impedance ◽  
Structural Health

Structural health monitoring of rotary aerospace structures is investigated in this research. A monitoring system is proposed based on the electromechanical impedance spectrum of piezoelectric transducers and a portable transceiver. To investigate the applicability and preliminary results of this method, a turbomachine prototype (laboratory device) is developed, and integrated composite piezoelectric films are deposited on the blades. Next, a self-diagnostic characterization is initially implemented to the piezo-films. Transceiver functionality and accuracy is verified using an Ivium impedance analyzer. The verified measuring path was used in structural health monitoring of pristine and damaged blades at rotational speed of 0 and 1000 r/min. The effects of damage formation and rotational speed on the impedance signature are discussed based on the variations in mechanical impedance using a two-dimensional model. Once damage occurs in a blade at each speed, it results in a frequency shift of the impedance signature at antiresonance peaks compared to the corresponding baseline. The results show a clear frequency shift of existing peaks and the appearance of new peaks as damage grows to a secure minimal detectable size. This achievement confirms the applicability of this method for incipient damage detection on rotary structures prior to any failure.

scholarly journals Large-Area Resistive Strain Sensing Sheet for Structural Health Monitoring

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1386 ◽  
Author(s):  
Levent E. Aygun ◽  
Vivek Kumar ◽  
Campbell Weaver ◽  
Matthew Gerber ◽  
Sigurd Wagner ◽  
...  
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Printed Circuit Board ◽  
Early Stage ◽  
Field Tests ◽  
Circuit Board ◽  
Gauge Factor ◽  
Peak Strain ◽  
Large Area ◽  
Structural Health

Damage significantly influences response of a strain sensor only if it occurs in the proximity of the sensor. Thus, two-dimensional (2D) sensing sheets covering large areas offer reliable early-stage damage detection for structural health monitoring (SHM) applications. This paper presents a scalable sensing sheet design consisting of a dense array of thin-film resistive strain sensors. The sensing sheet is fabricated using flexible printed circuit board (Flex-PCB) manufacturing process which enables low-cost and high-volume sensors that can cover large areas. The lab tests on an aluminum beam showed the sheet has a gauge factor of 2.1 and has a low drift of 1.5 μ ϵ / d a y . The field test on a pedestrian bridge showed the sheet is sensitive enough to track strain induced by the bridge’s temperature variations. The strain measured by the sheet had a root-mean-square (RMS) error of 7 μ ϵ r m s compared to a reference strain on the surface, extrapolated from fiber-optic sensors embedded within the bridge structure. The field tests on an existing crack showed that the sensing sheet can track the early-stage damage growth, where it sensed 600 μ ϵ peak strain, whereas the nearby sensors on a damage-free surface did not observe significant strain change.

Review of piezoelectric impedance based structural health monitoring: Physics-based and data-driven methods

2021 ◽  
pp. 136943322110384
Author(s):  
Xingyu Fan ◽  
Jun Li ◽  
Hong Hao
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Structural Damage ◽  
Low Frequency ◽  
Data Driven ◽  
Mode Shapes ◽  
Monitoring Methods ◽  
Destructive Testing ◽  
Electromechanical Impedance ◽  
Structural Health

Vibration based structural health monitoring methods are usually dependent on the first several orders of modal information, such as natural frequencies, mode shapes and the related derived features. These information are usually in a low frequency range. These global vibration characteristics may not be sufficiently sensitive to minor structural damage. The alternative non-destructive testing method using piezoelectric transducers, called as electromechanical impedance (EMI) technique, has been developed for more than two decades. Numerous studies on the EMI based structural health monitoring have been carried out based on representing impedance signatures in frequency domain by statistical indicators, which can be used for damage detection. On the other hand, damage quantification and localization remain a great challenge for EMI based methods. Physics-based EMI methods have been developed for quantifying the structural damage, by using the impedance responses and an accurate numerical model. This article provides a comprehensive review of the exciting researches and sorts out these approaches into two categories: data-driven based and physics-based EMI techniques. The merits and limitations of these methods are discussed. In addition, practical issues and research gaps for EMI based structural health monitoring methods are summarized.

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