scholarly journals Impact Damage Detection in Composite Plates using a Self-diagnostic Electro-Mechanical Impedance-based Structural Health Monitoring System

2015 ◽  
Vol 06 (04) ◽  
pp. 1550013 ◽  
Author(s):  
Z. Sharif-Khodaei ◽  
M. Ghajari ◽  
M. H. Aliabadi
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Health Monitoring ◽  
Impact Damage ◽  
Composite Plates ◽  
Mechanical Impedance ◽  
Experimental Tests ◽  
Health Monitoring System ◽  
Structural Health ◽  
Faulty Sensors

In this work, application of the electro-mechanical impedance (EMI) method in structural health monitoring as a damage detection technique has been investigated. A damage metric based on the real and imaginary parts of the impedance measures is introduced. Numerical and experimental tests are carried out to investigate the applicability of the method for various types of damage, such as debonding between the transducers and the plate, faulty sensors and impact damage in composite plates. The effect of several parameters, such as environmental effects, frequency sweep, severity of damage, location of damage, etc., on the damage metric has been reported.

An open database for benchmarking guided waves structural health monitoring algorithms on a composite full-scale outer wing demonstrator

2019 ◽  
Vol 19 (5) ◽  
pp. 1524-1541 ◽  
Author(s):  
Alessandro Marzani ◽  
Nicola Testoni ◽  
Luca De Marchi ◽  
Marco Messina ◽  
Ernesto Monaco ◽  
...  
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Monitoring System ◽  
Health Monitoring ◽  
Guided Wave ◽  
Full Scale ◽  
Composite Panel ◽  
Health Monitoring System ◽  
Electromechanical Impedance ◽  
Structural Health

This article reports on the creation of an open database of piezo-actuated and piezo-received guided wave signals propagating in a composite panel of a full-scale aeronautical structure. The composite panel closes the bottom part of a wingbox that, along with the leading edge, the trailing edge, and the wingtip, forms an outer wing demonstrator approximately 4.5 m long and from 1.2 to 2.3 m wide. To create the database, a structural health monitoring system, composed of a software/hardware central unit capable of controlling a network of 160 piezoelectric transducers secondarily bonded on the composite panel, has been realized. The structural health monitoring system has been designed to (1) perform electromechanical impedance measurement at each transducer, in order to check for their reliability and bonding strength, and (2) to operate an active guided wave screening for damage detection in the composite panel. Electromechanical impedance and guided wave measurements were performed at four different testing stages: before loading, before fatigue, before impacts, and after impacts. The database, freely available at http://shm.ing.unibo.it/ , can thus be used to benchmarking, on real-scale structural data, guided wave algorithms for loading, fatigue, as well as damage detection, characterization, and sizing. As an example, in this work, a delay and sum algorithm is applied on the post-impact data to illustrate how the database can be exploited.

Computation of Wave Propagation in Damped Specimen for Damage Detection

2014 ◽  
Vol 783-786 ◽  
pp. 2296-2301 ◽  
Author(s):  
Veena Jawali ◽  
Prakash Parasivamurthy ◽  
Ashwini Nagesh
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Monitoring System ◽  
Health Monitoring ◽  
Time Of Flight ◽  
Source Location ◽  
Wave Source ◽  
Health Monitoring System ◽  
Structural Health ◽  
Structural Health Monitoring System

Aim of a structural health monitoring system must be to collect sufficient information about the damage for appropriate remedial measures to be taken to ensure safety. The preliminary step in the process of damage assessment is locating the damage .One of the challenges faced by the structural health monitoring system is monitoring in-flight damages. Localization of in-flight damages or sudden impacts can be achieved by monitoring the acoustic emissions in real time mode. In this paper, an approach based on the employment of Piezo-electric transducer rosettes to locate the acoustic emission source in an aluminum plate is presented. Using the strain gage rosette concepts adapted for piezoelectric transducers, the wave strain principal angles are determined. When two rosettes are used, the intersection of the principal wave strain directions detected by the rosettes gives the wave source location. The method does not require the knowledge of wave velocity in the medium in contrast to the time of flight based location. Hence, this technique can be used in anisotropic or complex structures where the source localization using the conventional time of flight method is difficult. The principal strain angle using the voltage response of the transducers and the rosette principles are obtained and the co-ordinates of the wave source location are calculated using the co-ordinates of the centroids of the rosettes in MATLAB.According to the tests, the rosette piezo-transducer outperforms the single piezo elements to a degree justifying its complexity. The rosette piezo transducer provides more damage related information compared to single elements and hence the performance of the damage detection system can be significantly improved if rosettes are used.

SHM System Based on Modal Filtration

2012 ◽  
Vol 518 ◽  
pp. 289-297 ◽  
Author(s):  
Krzysztof Mendrok ◽  
Tadeusz Uhl ◽  
Wojciech Maj ◽  
Paweł Paćko
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Health Monitoring ◽  
Structural Modification ◽  
Structural Changes ◽  
Environmental Changes ◽  
Practical Implementation ◽  
Health Monitoring System ◽  
Structural Health ◽  
Changes Detection

The modal filter has various applications, among the others for damage detection. It was shown, that a structural modification (e.g. drop of stiffness due to a crack) causes an appearance of peaks on the output of the modal filter. This peaks result from not perfect modal filtration due to system local structural changes. That makes it a great indicator for damage detection, which has fallowing advantages: low computational afford due to the data reduction, the structural health monitoring system based on it, is easy to automate. Furthermore the system is theoretically insensitive to environmental changes as temperature or humidity variation (global structural changes do not cause a drop of modal filtration accuracy). In the paper the practical implementation of the presented technique is shown. The developed structural health monitoring (SHM) system is described as well as results of its extensive simulation and laboratory testing. Finally the application of the system for the structural changes detection on the airplane parts is presented..

Structural Health Monitoring of Composite Structures Using Guided Lamb Waves

2006 ◽  
Vol 321-323 ◽  
pp. 759-764 ◽  
Author(s):  
Krishnan Balasubramaniam ◽  
B.V. Soma Sekhar ◽  
J. Vishnu Vardan ◽  
C.V. Krishnamurthy
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Composite Structures ◽  
Lamb Waves ◽  
Impact Damage ◽  
Composite Plates ◽  
Structural Features ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Structural Health

Structural Health Monitoring (SHM) of aircrafts is of great relevance in the present age aircraft industry. The present study demonstrates three techniques that have the potential for the SHM of multi-layered composite structures. The first technique is based on multi-transmitter-multireceiver (MTMR) technique with tomographic methods used for data reconstruction. In the MTMR, the possibility of SHM using algebraic reconstruction techniques (ART) for tomographic imaging with Lamb wave data measured in realistic materials is examined. Defects (through holes and low velocity impact delaminations) were synthetic and have been chosen to simulate impact damage in composite plates. The second technique is a single-transmitter-multi-receiver (STMR) technique that is more compact and uses reconstruction techniques that are analogous to synthetic aperture techniques. The reconstruction algorithm uses summation of the phase shifted signals to image the location of defects, portions of the plate edges, and any reflectors from inherent structural features of the component. The third technique involves a linear array of sensors across a stiffener for the detection of disbanded regions.

Data Mining for Structural Health Monitoring

2011 ◽  
pp. 450-457 ◽  
Author(s):  
Ramdev Kanapady ◽  
Aleksandar Lazarevic
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Monitoring System ◽  
Health Monitoring ◽  
Structural Systems ◽  
Health Monitoring System ◽  
Structural Health ◽  
Human Labor ◽  
Periodic Monitoring ◽  
Increasing Demand

Structural health monitoring denotes the ability to collect data about critical engineering structural elements using various sensors and to detect and interpret adverse “changes” in a structure in order to reduce life-cycle costs and improve reliability. The process of implementing and maintaining a structural health monitoring system consists of operational evaluation, data processing, damage detection and life prediction of structures. This process involves the observation of a structure over a period of time using continuous or periodic monitoring of spaced measurements, the extraction of features from these measurements, and the analysis of these features to determine the current state of health of the system. Such health monitoring systems are common for bridge structures and many examples are citied in (Maalej et al., 2002). The phenomenon of damage in structures includes localized softening or cracks in a certain neighborhood of a structural component due to high operational loads, or the presence of flaws due to manufacturing defects. Damage detection component of health monitoring system are useful for non-destructive evaluations that are typically employed in agile manufacturing systems for quality control and structures, such as turbine blades, suspension bridges, skyscrapers, aircraft structures, and various structures deployed in space for which structural integrity is of paramount concern (Figure 1). With the increasing demand for safety and reliability of aerospace, mechanical and civilian structures damage detection techniques become critical to reliable prediction of damage in these structural systems. Most currently used damage detection methods are manual such as tap test, visual or specially localized measurement techniques (Doherty, 1997). These techniques require that the location of the damage have to be on the surface of the structure. In addition, location of the damage has to be known a priori and these locations have to be readily accessible. This makes current maintenance procedure of large structural systems very time consuming and expensive due to its heavy reliance on human labor.

scholarly journals Validation of a procedure for the evaluation of the performance of an installed structural health monitoring system

2018 ◽  
Vol 18 (5-6) ◽  
pp. 1557-1568 ◽  
Author(s):  
Sebastian Heinlein ◽  
Peter Cawley ◽  
Thomas Vogt
Keyword(s):  
Finite Element ◽  
Structural Health Monitoring ◽  
Damage Detection ◽  
Monitoring System ◽  
Health Monitoring ◽  
Complex Structure ◽  
Detection Ability ◽  
Health Monitoring System ◽  
Structural Health ◽  
Structural Health Monitoring System

Validation of the performance of guided wave structural health monitoring systems is vital if they are to be widely deployed; testing the damage detection ability of a system by introducing different types of damage at varying locations is very costly and cannot be performed on a system in operation. Estimating the damage detection ability of a system solely by numerical simulations is not possible as complex environmental effects cannot be accounted for. In this study, a methodology was tested and verified that uses finite element simulations to superimpose defect signals onto measurements collected from a defect-free structure. These signals are acquired from the structure of interest under varying environmental and operational conditions for an initial monitoring period. Measurements collected in a previous blind trial of an L-shaped pipe section, onto which a number of corrosion-like defects were introduced, were utilised during this investigation. The growth of three of these defects was replicated using finite element analysis and the simulated reflections were superimposed onto signals collected on the defect-free test pipe. The signal changes and limits of reliable detection predicted from the synthetic defect reflections superimposed on the measurements from the undamaged complex structure agreed well with the changes due to real damage measured on the same structure. This methodology is of great value for any structural health monitoring system as it allows for the minimum detectable defect size to be estimated for specific geometries and damage locations in a quick and efficient manner without the need for multiple test structures while accounting for environmental variations.

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