Ultrasonic health monitoring in structural engineering: buildings and bridges

Mutlib, Nadom Khalifa; Baharom, Shahrizan; El-Shafie, Ahmed; Nuawi, Mohd. Zaki

doi:10.1002/stc.1800

Cited by 87 publications

(55 citation statements)

References 101 publications

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“…Suppose the intensity of the crack in the element is k N ; then, the deformation of the element caused by stress σ can be calculated by Equation (8).…”

Section: Crack Deformation Under Uni-axial Stressmentioning

confidence: 99%

“…According to the acoustics (emitted by the internal crack or generated by a transducer) received from the structure, the internal damage of the structure can be monitored [5]. Among NDT technologies, acoustic wave velocity in concrete has been widely used in the determination of concrete elastic modulus, strength measurement, and damage detection [6][7][8][9]. However, due to the characteristics of multicomponent and inhomogeneous concrete materials, the traditional acoustic measurement technology faces great challenges in the application of concrete stress measurement [10].…”

Section: Introductionmentioning

confidence: 99%

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Correlation between Coda Wave and Stresses in Uni-Axial Compression Concrete

et al. 2018

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Stresses in structures are usually converted by measured strains based on corresponding constitutive relations of materials. However, it is difficult to determine the constitutive relation of the material accurately, which leads to significant uncertainty of the converted stresses. This paper proposed a method to estimate the stresses in concrete by using the coda wave interference technique and established a model to describe the relation between the deformation of microcracks and the sound velocity. Based on the experiments, the development law of the coda waves with different frequencies of sound signal propagating in concrete was verified and discussed, and the change of the coda wave velocity during the loading and unloading of the specimen was tested. Parameters involved in the established model were regressed according to the experimental data. The analysis results show that the method can be used to test concrete stress and has a desirable accuracy. coda wave analysis method in 1969 [12]. In 2002, Snieder et al. used CWI to estimate the nonlinearity of the seismic wave velocity and found that CWI exhibited extreme sensitivity to variations in the medium [13]. After that, the researchers further improved the effectiveness of CWI on the measurement for velocity variation in concrete caused by temperature [14], micro damage [15][16][17], and a uniform stress field [18]. In 2014, Niederleithinger conducted an experimental study to demonstrate the effectiveness of CWI in concrete stress measurement [19].McCann and Forde pointed out that the development of NDT should depend on a better understanding of the performance of materials and forward modeling. Moreover, it should put forward a practical method to obtain high accuracy and realistic feasibility results from NDT [4]. Therefore, the correlation between the stress and the coda wave velocity of concrete should be discussed for the better application of CWI technology in concrete stress detection. Microcracks in concrete close or expand under stresses, leading to changes in the medium's characteristics. The tiny changes in the concrete acoustic-elasticity properties can be amplified by CWI, and its accuracy can reach up to 2 × 10 −5 [6]. It is feasible to estimate stress using CWI according to the correlation between the coda wave velocity and microcracks [20]. This paper discussed the mechanism of detecting the stress of concrete using the CWI technique. A correlation model of sound velocity and stress in concrete based on the acoustic elasticity theory was proposed. An experimental study was conducted to measure the changes of wave velocity in the concrete under stress according to the CWI technique. Overall, this paper provided a new approach for stress estimation in concrete structures. Correlation Model of Sound Velocity and Stress in ConcreteSound velocity in concrete is mainly determined by the elastic parameters of concrete. The development of microcracks in concrete under stresses would change the elastic parameters of the concrete medium, resulting ...

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“…Suppose the intensity of the crack in the element is k N ; then, the deformation of the element caused by stress σ can be calculated by Equation (8).…”

Section: Crack Deformation Under Uni-axial Stressmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Correlation between Coda Wave and Stresses in Uni-Axial Compression Concrete

et al. 2018

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“…Natural frequencies and vibration modes are essential dynamic characteristics of a structure, which have been widely used in structural health monitoring or damage detection . A variety of modal analysis and extraction methods have been proposed in the past decades .…”

Section: Introductionmentioning

confidence: 99%

Mode localization characteristics of damaged quasiperiodically supported beam structures with local weak coupling

Ying

Kang

2019

Struct Control Health Monit

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KEYWORDS frequency loci veering, local weak coupling, mode localization, quasiperiodically supported beam, support damage 1 | INTRODUCTION Natural frequencies and vibration modes are essential dynamic characteristics of a structure, which have been widely used in structural health monitoring or damage detection. 1-11 A variety of modal analysis and extraction methods have been proposed in the past decades. [12][13][14][15][16][17][18][19] The extracted low-order vibration modes from a complex structure in general have higher accuracy than high-order vibration modes. However, structural high-order vibration modes are more sensitive to local damage than low-order modes, and thus the reliability of modal-based damage detection is influenced by the sensitivity and accuracy of extracted modal properties. The use of low-order vibration modes such as the fundamental mode is a more effective method for structural damage detection.Many engineering structures have geometric and physical periodicity, for example, continuous girder viaducts and bridges with periodically spaced supports (supports are equally spaced and have identical stiffness). The dynamic characteristics of periodic structures have been studied extensively. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] The periodically supported beam consists of multiple spans, and the adjacent spans share the same displacement and angular rotation at the joint support due to continuity. For small support stiffness, the continuity of displacement and angular rotation indicates a strong coupling of the periodically supported beam between adjacent spans. On the contrary, for large support stiffness, the support displacement of the beam, for example, in the fundamental vibration mode is close to zero, and then the beam between spans has coupling only in angular rotation, which is the so-called local weak coupling. The periodically supported beam is a local weak coupling beam when the support stiffness is higher than a certain value. 39,40 Nevertheless, the periodically supported beam with local weak coupling leads to a quasiperiodically supported beam if the stiffness in one or a few supports is weakened due to damage. When the support stiffness is lowered to be smaller than a critical value, the fundamental natural frequency of the quasiperiodically supported beam manifests frequency loci veering, and its fundamental vibration mode exhibits modal jump. The modal jump yields a noticeable increase of absolute displacement of the fundamental vibration mode around the stiffness-reduced support, which is the so-called mode localization. 40 The dynamic characteristics such as fundamental mode localization of the quasiperiodically supported beam with local weak coupling rely directly on the support stiffness, and the mode localization is around the stiffness-reduced support. These outstanding dynamic characteristics of quasiperiodically supported structures have the potential to be applied for detecting and locating support damage based on the fundamen...

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“…Increasing the life span of our infrastructures while maintaining a high level of safety to withstand operational and environmental loading has generated the interests to many researchers and engineering scientists to consider continuous monitoring methods known as structural health monitoring (SHM). SHM can be a complementary approach to the current nondestructive testing methods, such as eddy currents and ultrasonics, which can only provide local monitoring and are associated with a very high cost. Driven by this incentive, a large number of algorithms were developed during the last two decades that aimed to provide a continuous monitoring using vibration measurements …”

Section: Introductionmentioning

confidence: 99%

Frequency domain decomposition-based multisensor data fusion for assessment of progressive damage in structures

Alamdari

Anaissi

Khoa

et al. 2018

Struct Control Health Monit

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Summary In this paper, we focused on the development and verification of a solid and robust framework for structural condition assessment of real‐life structures using measured vibration responses, with the presence of multiple progressive damages occurring within the inspected structures. A self‐tuning learning method for structural condition assessment was proposed. Damage sensitive features were extracted using a frequency domain decomposition (FDD) approach to fuse all the measured responses, followed by random projection algorithm for dimensionality reduction. An automatic parameter selection method called Appropriate Distance to the Enclosing Surface (ADES) was used for tuning the classifier parameter. The effect of operational conditions on the robustness of the proposed method was also investigated, and it was realized that application of FDD to extract damage sensitive feature reduces the variation in the results. Promising results in the assessment of damage were obtained based on two comprehensive case studies, which included single and multiple damage scenarios. The contributions of the work are threefold. First, through two comprehensive case studies, we demonstrate that the frequency‐based feature from a single sensor might not be adequate enough to detect the progress of damage, even if the sensor is in the vicinity of damage. Second, we show that data fusion using FDD can reliably assess the severity of damage, and finally, we propose a new automated approach for tuning the classifier parameter.

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Ultrasonic health monitoring in structural engineering: buildings and bridges

Cited by 87 publications

References 101 publications

Correlation between Coda Wave and Stresses in Uni-Axial Compression Concrete

Correlation between Coda Wave and Stresses in Uni-Axial Compression Concrete

Mode localization characteristics of damaged quasiperiodically supported beam structures with local weak coupling

Frequency domain decomposition-based multisensor data fusion for assessment of progressive damage in structures

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