Crack detection in pile by measurements of frequency response function

Khiem, Nguyen Tien; Hang, P. T.; Toan, Le Khanh

doi:10.1080/10589759.2015.1081904

Cited by 7 publications

(6 citation statements)

References 20 publications

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“…(10) The obtained equation 9is desired explicit form of the characteristic equation that provides an efficient tool for solving not only the forward but also the inverse problem of multiple cracked bar. Note, another form of the characteristic equation for multiple cracked rod was exactly obtained by Shifrin in [7], but that equation is implicit with respect to the crack magnitudes, likely, the equation given by Khiem et al in [14].…”

Section: Substituting Latter Expressions Into (8) One Obtainsmentioning

confidence: 99%

“…θ(z) = 0.9852z 2 + 0.2381z 3 − 1.0368z 4 + 1.2055z 5 + 0.5803z 6 − 1.0368z 7 + 0.7314z 8 . (4) It can be shown that any solution of equation 1satisfying the first boundary condition in (2) at x = 0 and conditions (3) inside the bar is expressed in the form [14]…”

Section: General Frequency Equation For Multiple Cracked Barmentioning

confidence: 99%

“…However, the study showed that unique solution of the crack detection cannot be found by using only natural frequencies. Some efforts have been made to solve the problem by encompassing other vibration characteristics such mode shapes [11][12][13] or frequency response function [14], but it was successful when antiresonant frequencies have been employed [15][16][17]. Nevertheless, using additionally the c 2019 Vietnam Academy of Science and Technology antiresonant frequencies for crack detection in bar enables to obtain unique solution of the crack detection problem only for free end bar.…”

Section: Introductionmentioning

confidence: 99%

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Resonant and antiresonant frequencies of multiple cracked bar

Lien

Khiem

2019

Vietnam J. Mech.

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The natural frequencies or related resonant frequencies have been widely used for crack detection in structures by the vibration-based technique. However, antiresonant frequencies, the zeros of frequency response function, are less involved to use for the problem because they have not been thoroughly studied. The present paper addresses analysis of antiresonant frequencies of multiple cracked bar in comparison with the resonant ones. First, exact characteristic equations for the resonant and antiresonant frequencies of bar with arbitrary number of cracks are conducted in a new form that is explicitly expressed in term of crack severities. Then, the conducted equations are employed for analysis of variation of resonant and antiresonant frequencies versus crack position and depth. Numerical results show that antiresonant frequencies are indeed useful indicators for crack detection in bar mutually with the resonant one

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Section: Substituting Latter Expressions Into (8) One Obtainsmentioning

confidence: 99%

Section: General Frequency Equation For Multiple Cracked Barmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Resonant and antiresonant frequencies of multiple cracked bar

Lien

Khiem

2019

Vietnam J. Mech.

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“…is is the foundation for many national managers and scientists including [22][23][24][25][26] or foreign ones such as [27][28][29][30][31][32][33] to choose this value as a measuring scale for general deterioration of spans (through testing standards, design criteria, etc.). According to [34], researchers have figured out parameters that are often used to evaluate the reduction of bearing capacity of spans like deflection values, deformation values, damping coefficient values, and impact coefficient values.…”

Section: Shock and Vibrationmentioning

confidence: 99%

A New Insight to Vibration Characteristics of Spans under Random Moving Load: Case Study of 38 Bridges in Ho Chi Minh City, Vietnam

Nguyen

Tran

et al. 2020

Shock and Vibration

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We propose a novel representative power spectrum density as a specific characteristic for showing responses of spans during a long operational period. The idea behind this method is to use the representative power spectrum density as a powerful tool to evaluate the stiffness decline of spans during their operation period. In addition, a new measurement method has been introduced to replace the traditional method of monitoring the health conditions of bridges through a periodic measurement technique. This helps to reduce costs when carrying out testing bridges. Besides, the proposed approach can be widely applied not only in Vietnam but also in many other underprivileged countries around the world. Obtained results show that, during the operational process of spans, there is not only a pure vibration evaluation such as bending vibration and torsion vibration tests but also a combination of various vibration types including bending-torsion vibration or high-level vibrations like first-mode bending and first-mode torsion. Depending on each type of structure and material properties, different types of vibrations will appear more or less during the operational process of spans under a random moving load. Furthermore, the representative power spectrum density is also suitable for evaluating and determining many different fundamental vibrations through the same measurement time as well as various measurement times.

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“…Based on modal curvature, Wang et al [ 19 ] analyzed the influence of each node on the overall CMD curve shape through a data deletion model and established statistical characteristic indicators reflecting the difference between damaged units and undamaged units. Khie et al [ 20 ] derived and used frequency equations and display expressions for frequency response functions to identify and evaluate damage.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation and Damage Identification of High-Pile Wharf Framed Bents under Horizontal Impact Loads

Zheng,

Xiao,

Zhang

et al. 2024

Sensors

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This study investigates damage characteristics, dynamic structural performance changes, and quantitative damage assessment of high-pile wharf framed bents exposed to horizontal impact loads. Through extensive testing of wharf framed bents under such loads, a damage identification approach based on stiffness, natural vibration period, and acceleration data derived from experiments is presented. The findings reveal that under horizontal impact loads, framed bents initially exhibit tensile damage and leaning piles, followed by short straight piles. Additionally, structural damage results in a reduced self-oscillation frequency and an increased amplitude decay rate. Both stiffness-based and cycle-based damage indicators effectively track the cumulative damage progression of the structure. However, the cycle-based damage indicators demonstrate superior stability and accuracy, while acceleration-based indicators precisely identify the moment of damage mutation. This research contributes to enhancing local components, implementing damage identification methods, and advancing health monitoring practices in high-pile wharf projects, aligning with the standards of scientific publications in the field.

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Crack detection in pile by measurements of frequency response function

Cited by 7 publications

References 20 publications

Resonant and antiresonant frequencies of multiple cracked bar

Resonant and antiresonant frequencies of multiple cracked bar

A New Insight to Vibration Characteristics of Spans under Random Moving Load: Case Study of 38 Bridges in Ho Chi Minh City, Vietnam

Experimental Investigation and Damage Identification of High-Pile Wharf Framed Bents under Horizontal Impact Loads

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