Part Authentication Using Indirect Electromechanical Impedance Measurements

Abstract Motivated by its success as a structural health monitoring solution, electromechanical impedance measurements have been utilized as a means for non-destructive evaluation of conventionally and additively manufactured parts. In this process, piezoelectric transducers are either directly embedded in the part under test or bonded to its surface. While this approach has proven to be capable of detecting manufacturing anomalies, instrumentation requirements of the parts under test have hindered its wide adoption. To address this limitation, indirect electromechanical impedance measurement, through instrumented fixtures or testbeds, has recently been investigated for part authentication and non-destructive evaluation applications. In this work, electromechanical impedance signatures obtained with piezoelectric transducers indirectly attached to the part under test, via an instrumented fixture, are numerically investigated. This aims to better understand the coupling between the instrumented fixture and the part under test and its effects ON sensitivity to manufacturing defects. For this purpose, numerical models are developed for the instrumented fixture, the part under test, and the fixture/part assembly. The frequency-domain spectral element method is used to obtain numerical solutions and simulate the electromechanical impedance signatures over the frequency range of 10–50 kHz. Criteria for selecting the frequency range that is most sensitive to defects in the part under test are proposed and evaluated using standard damage metric definitions. It was found that optimal frequency ranges can be preselected based on the fixture design and its dynamic response.

Non Destructive Evaluation Based on Impedance Method Using Embedded PZT Sensor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.35 ◽

2009 ◽

Vol 79-82 ◽

pp. 35-38 ◽

Cited By ~ 1

Author(s):

Dong Yu Xu ◽

Xin Cheng ◽

Shi Feng Huang ◽

Min Hua Jiang

Keyword(s):

Structural Damage ◽

Crack Depth ◽

Impedance Method ◽

Impedance Spectra ◽

Increasing Trend ◽

Impedance Technique ◽

Impedance Curve ◽

The structural damage of mortar caused by simulated crack was evaluated using embedded PZT sensor combining with dynamic electromechanical impedance technique. The influence of embedded PZT sensors layout on detecting structural damage induced by the simulated cracks was also investigated. The results indicate that with increasing the simulated crack depth, the impedance real part of PZT sensors shift leftwards accompanying with the appearance of new peaks in the spectra. When more simulated cracks occur, the shift of the impedance curve becomes more obvious, and the amounts of new peaks in the impedance spectra also increase. RMSD indices of the structures with PZT sensors embedded in them with different layout can show the structural incipient damage clearly. With increasing more simulated cracks in the mortar structures, RMSD values of the structures with different PZT sensors layout become larger, under the same depth, RMSD indices of the structures with PZT sensor embedded transversely and horizontally in them show the increasing trend.

A multi-sensing electromechanical impedance method for non-destructive evaluation of metallic structures

Smart Materials and Structures ◽

10.1088/0964-1726/22/9/095011 ◽

2013 ◽

Vol 22 (9) ◽

pp. 095011 ◽

Cited By ~ 20

Author(s):

S Na ◽

H K Lee

Keyword(s):

Impedance Method ◽

Metallic Structures ◽

IMTC/98 Conference Proceedings. IEEE Instrumentation and Measurement Technology Conference. Where Instrumentation is Going (Cat. No.98CH36222) ◽

Multi-probe impedance measurement system for non-destructive evaluation and test of "green state" powder metallurgy parts

10.1109/imtc.1998.679816 ◽

2002 ◽

Author(s):

J. Stander ◽

J.A. McNeill ◽

R. Ludwig

Keyword(s):

Powder Metallurgy ◽

Measurement System ◽

Impedance Measurement ◽

Green State ◽

Non-destructive Evaluation of Integrated Piezoelectric Transducers by Thermal Waves and Thermal Pulses

Procedia Technology ◽

10.1016/j.protcy.2016.08.009 ◽

2016 ◽

Vol 26 ◽

pp. 59-65 ◽

Cited By ~ 3

Author(s):

Agnes Eydam ◽

Gunnar Suchaneck ◽

Gerald Gerlach

Keyword(s):

Piezoelectric Transducers ◽

Thermal Waves ◽

Non Destructive ◽

Thermal Pulses

Impedance-based non-destructive evaluation of additively manufactured parts

Rapid Prototyping Journal ◽

10.1108/rpj-03-2016-0046 ◽

2017 ◽

Vol 23 (3) ◽

pp. 589-601 ◽

Cited By ~ 12

Author(s):

Mohammad I. Albakri ◽

Logan D. Sturm ◽

Christopher B. Williams ◽

Pablo A. Tarazaga

Keyword(s):

Complex Geometry ◽

Cost Effective ◽

Learning Context ◽

Content Type ◽

Internal Porosity ◽

The Impact ◽

Non Destructive ◽

Am Processes

Purpose This work proposes the utilization of electromechanical impedance measurements as a means of non-destructive evaluation (NDE) for additive manufacturing (AM). The effectiveness and sensitivity of the technique for a variety of defect types commonly encountered in AM are investigated. Design/methodology/approach To evaluate the feasibility of impedance-based NDE for AM, the authors first designed and fabricated a suite of test specimens with build errors typical of AM processes, including dimensional inaccuracies, positional inaccuracies and internal porosity. Two polymer AM processes were investigated in this work: material jetting and extrusion. An impedance-based analysis was then conducted on all parts and utilized, in a supervised learning context, for identifying defective parts. Findings The newly proposed impedance-based NDE technique has been proven to be an effective solution for detecting several types of print defects. Specifically, it was shown that the technique is capable of detecting print defects resulting in mass change (as small as 1 per cent) and in feature displacement (as small as 1 mm) in both extruded nylon parts and jetted VeroWhitePlus parts. Internal porosity defects were also found to be detectable; however, the impact of this defect type on the measured impedance was not as profound as that of dimensional and positional inaccuracies. Originality/value Compared to currently available NDE techniques, the newly proposed impedance-based NDE is a functional-based technique with the advantages of being cost-effective, sensitive and suitable for inspecting AM parts of complex geometry and deeply embedded flaws. This technique has the potential to bridge the existing gaps in current NDE practices, hence paving the road for a wider adoption of AM to produce mission-critical parts.

Damage Detection with Auxiliary Subsystem

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.56.401 ◽

2008 ◽

Vol 56 ◽

pp. 401-413 ◽

Cited By ~ 1

Author(s):

Fabrizio Vestroni ◽

J. Ciambella ◽

Francesco dell'Isola ◽

Stefano Vidoli

Keyword(s):

Damage Detection ◽

Mechanical System ◽

Mechanical Characteristics ◽

Piezoelectric Transducers ◽

The Other ◽

Monitoring Systems ◽

Highly Sensitive ◽

Non Destructive ◽

Remarkable Advantage

Among Non-Destructive Evaluation, vibration-based methods respond to the current ten- dency which is to integrate into the structure identication and monitoring systems; to this aim transducers and sensors are embedded with the mechanical system and driven by suitably designed electronic controllers. The major limit of this and the other indirect identication techniques based on frequency response measurements turns out to be the small sensitivity to local variations of mechanical characteristics: it re ects on a uncertainty on the identied parameters, since it implies a small curvature of any reasonable identication functional build on these quantities. An enlightening example for the application of the proposed technique is given through a beam- like structure coupled to a network of piezoelectric patches. Although the forces exerted by the piezoelectric transducers are not large, the choice of such a kind of actuators/sensors implies the remarkable advantage of dealing with highly sensitive and easily tunable devices.

Non-Destructive Evaluation of Rock Bolt Grouting Quality by Analysis of Its Natural Frequencies

Materials ◽

10.3390/ma13020282 ◽

2020 ◽

Vol 13 (2) ◽

pp. 282 ◽

Cited By ~ 2

Author(s):

Mario Bačić ◽

Meho Saša Kovačević ◽

Danijela Jurić Kaćunić

Keyword(s):

Load Transfer ◽

Natural Frequencies ◽

Numerical Models ◽

Rock Bolt ◽

Load Transfer Mechanism ◽

Stiffness Variation ◽

Non Destructive ◽

Laboratory Models ◽

Grouted Rock Bolts

Grouted rock bolts represent one of the most used elements for rock mass stabilization and reinforcement and the grouting quality has a crucial role in the load transfer mechanism. At the same time, the grouting quality as well as the grouting procedures are the least controlled in practice. This paper deals with the non-destructive investigation of grouting percentage through an analysis of the rock bolt’s natural frequencies after applying an artificial longitudinal impulse to its head by using a soft-steel hammer as a generator. A series of laboratory models, with different positions and percentages of the grouted section, simulating grouting defects, were tested. A comprehensive statistical analysis was conducted and a high correlation between the grouting percentage and the first three natural frequencies of rock bolt models has been established. After validation of FEM numerical models based on experimentally obtained values, a further analysis includes consideration of grout stiffness variation and its impact on natural frequencies of rock bolt.