Ultrasonic Techniques for Baseline-Free Damage Detection in Structures (original) (raw)
Related papers
Ultrasonic health monitoring in structural engineering: buildings and bridges
Structural Control and Health Monitoring, 2015
Ultrasonic monitoring is one of the most important tools in the field of structural health monitoring (SHM). The main goal of this paper is to provide a comprehensive review of the recent advances and achievements in ultrasonic wave SHM of buildings and bridges built with concrete and steel materials and the types of sensors used in these structures. In this paper, the parameters affecting the monitoring process, including the type of damage, the type of ultrasonic wave, and the type of sensor, are reviewed. The sensor devices used to transmit and receive ultrasonic waves, like lead zirconate titanate, electromagnetic acoustic transducer, and others and their applications in building and bridges, are discussed. The limitations of each type of theses sensors are highlighted. Finally, conclusions are drawn and recommendations for an improved sensor overcoming the shortcomings of the current sensors are given.
2005
Changes in diffuse ultrasonic signals recorded from permanently mounted sensors can be correlated to initiation and growth of structural damage, offering hope that sparse sensor arrays can be utilized for monitoring large areas. It is well-known that benign environmental changes also have significant effects on diffuse ultrasonic signals that are of comparable magnitude to the effects of damage. Several methodologies are investigated for quantifying differences in diffuse ultrasonic signals by computing parameters that can be used to discriminate damage from environmental changes. The methodologies considered are waveform differencing, spectrogram differencing, change in local temporal coherence, and temperature compensated differencing. For all four methods, a set of baseline waveforms are first recorded from the undamaged specimen at a range of temperatures, and subsequently recorded waveforms are compared to those of the baseline set. Experimental data from aluminum plate specimens with artificial defects are analyzed. Results show that the local coherence method is the most effective for discriminating damage from temperature changes whereas waveform differencing is the least effective. Both the spectrogram differencing method and the temperature compensated differencing method offer intermediate performance. As expected, the efficacy of all four methods improves as the number of waveforms in the baseline set increases.
2020
In structural health monitoring, crack identification using scattered ultrasonic waves from a crack is one of the most active research areas. Crack size estimation is important for judging the severity of the damage. If measurements are frequently performed as the crack grows, then a better estimation of crack size may be possible by analyzing sensor signals for the same crack location with different sizes. The objective of this article is to explore the relationship between the sensor signal amplitude and crack size through experiments and simulation for estimating the size. Cracks are machined into an aluminum plate and measurements are carried out with ultrasound excitation using piezoelectric transducer arrays that alternate their role as actuators or sensors. Initially, a hole of 2.5 mm diameter is drilled in the plate, and it is gradually machined to a crack with a size up to 50 mm. Signal amplitude is measured from the sensor arrays. The migration technique is used to image t...
Methodology for Detecting Progressive Damage in Structures Using Ultrasound-Guided Waves
Sensors, 2022
Damage detection in structural health monitoring of metallic or composite structures depends on several factors, including the sensor technology and the type of defect that is under the spotlight. Commercial devices generally used to obtain these data neither allow for their installation on board nor permit their scalability when several structures or sensors need to be monitored. This paper introduces self-developed equipment designed to create ultrasonic guided waves and a methodology for the detection of progressive damage, such as corrosion damage in aircraft structures, i.e., algorithms for monitoring such damage. To create slowly changing conditions, aluminum- and carbon-reinforced polymer plates were placed together with seawater to speed up the corrosion process. The setup was completed by an array of 10 piezoelectric transducers driven and sensed by a structural health monitoring ultrasonic system, which generated 100 waveforms per test. The hardware was able to pre-process...
Non Destructive Evaluation and Structural Health Monitoring: A Review
— Structural health monitoring has great potential for enhancing the functionality, serviceability and increased life span of structures. Structural health monitoring is defined as " continuous, autonomous, real time, in-service monitoring of the physical condition of a structure by means of embedded or attached sensors with minimum manual intervention". This need which arises from the fact that intensive usage combined with long endurance causes gradual but unnoticed deterioration in structures, often leading to unexpected disasters. Recently smart piezoelectric-ceramic lead material is emerged as high frequency impedance transducers for non-destructive evaluation. In this role, the PZT patches act as collocated actuators and sensors and employ ultrasonic vibrations gives a characteristic admittance 'signature' of the structure. The admittance signature has vital information about the nature of the structure, and it can be analysed to predict the onset of structural damages. PZT patches exhibit excellent performance as far as damage sensitivity. Their sensitivity is high enough to capture any structural damage at the incipient stage. There are different Non-Destructive techniques like acoustic emission, ultrasonic, acousto-ultrasonic, guided ultrasonic waves or Lamb waves. The Lamb wavebased active SHM method uses piezoelectric (PZT) sensors to transmit and receive wave. Thus, Lamb waves generated by PZT sensors and time-frequency analysis techniques could be used effectively for damage detection. This study has given a complete idea of the working and the basic requirements of SHM system.
2005
In this paper we review the state of the art in an emerging new technology: embedded ultrasonic non-destructive evaluation (NDE). Embedded ultrasonic NDE permits active structural health monitoring, i.e. the on-demand interrogation of the structure to determine its current state of structural health. The enabling element of embedded ultrasonic NDE is the piezoelectric wafer active sensor (PWAS). We begin by reviewing the guided wave theory in plate, tube, and shell structures, with special attention to Lamb waves. The mechanisms of Lamb wave excitation and detection with embeddable PWAS transducers is presented. It is shown analytically and verified experimentally that Lamb wave mode tuning can be achieved by the judicious combination of PWAS dimensions, frequency value, and Lamb mode characteristics. Subsequently, we address in turn the use of pitch-catch, pulse-echo, and phased array ultrasonic methods for Lambwave damage detection. In each case, the conventional ultrasonic NDE results are contrasted with embedded NDE results. Detection of cracks, disbonds, delaminations, and diffuse damage in metallic and composite structures are exemplified. Other techniques, such as the time reversal method and the migration technique, are also presented. The paper ends with conclusions and suggestions for further work.
Structural Control and Health Monitoring, 2013
The analysis and extraction of the appropriate signal's features in structural health monitoring applications is one of the major challenges on which the robustness of the designed systems relies. Many strategies have been developed in the past, which utilise the identification of amplitude-based parameters for the evaluation of structural integrity. However, these parameters usually require a baseline reference, which might be extensively affected by noise, environmental or mounting conditions. This paper illustrates the applicability of Hilbert transform and Hilbert-Huang transform on the postprocessing of guided ultrasonic waves for evaluating the condition of relatively complex structural health monitoring applications. Two case studies are presented to demonstrate the suitability of the techniques, namely, the damage monitoring of an aluminium repaired panel and the cure level monitoring of symmetric carbon fibre-epoxy composite laminates. In the first case study, the technique exhibits sensitivity in propagation paths within damaged areas and shows good agreement with the developed damage, enabling the identification of critical areas. In the second study, the technique demonstrates a significant advantage over the traditionally adopted approaches and predicts accurately the cure level of the polymeric composite system.
Structural Health Monitoring of Bridges by Using Ultrasonic Sensor
VIVA-Tech International Journal for Research and Innovation, 2021
Bridges are vital components of the Indian surface transportation system and support the growth of this nation's economy. But recent unexpected collapses and near to collapses of bridges underline the need for effective structural monitoring. There are multiple causes: poor technical state of bridges and roads, failure to traffic rules, vehicle built to modern highway traffic regime As the cost for monitoring and repair is much lower than the cost for reconstruction of new structures, monitoring is vital for civil infrastructure facilities, which form the lifeline of our country's economy. Current maintenance operations and integrity checks on a wide array of structures require personnel entry into normally-inaccessible or hazardous areas to perform necessary nondestructive inspections. Recently there has been increase in need for adopting smart sensing technologies to SHM so this review focus on sensing, monitoring and assessment for civil infrastructure. At present, the commonly used crack detection methods include physical and electrochemical methods, but there are shortcomings such as large equipment area, low detection frequency, and complex operation. This research develops and validates an array of Ultrasonic sensors for surface crack detection. It is a non-destructive testing (NDT) with potential applications for locating and up monitoring cracks and flaws during structural health management. This research presents the quantitative crack detection capabilities of the Ultrasonic sensor, its performance in actual structural environments, and the prospects for structural health monitoring applications.
Proceedings of 5th International Electronic Conference on Sensors and Applications
The development of new low-cost transducers and systems has been extensively aimed at in both industry and academia to promote a correct failure diagnosis in aerospace, naval, and civil structures. In this context, structural health monitoring (SHM) engineering is focused on promoting human safety and a reduction in the maintenance costs of these components. Traditionally, SHM aims to detect structural damages at the initial stage, before it reaches a critical level of severity. Numerous approaches for damage identification and location have been proposed in the literature. One of the most common damage location techniques is based on acoustic waves triangulation, which stands out as an effective approach. This method uses a piezoelectric transducer as a sensor to capture acoustic waves emitted by cracks or other damage. Basically, the damage location is defined by calculating the difference in the time of arrival (TOA) of the signals. Although it may be simple, the detection of TOA...