Damage Detection of Reinforced Concrete Beams by Wavelet Analysis

2012 ◽  
Vol 166-169 ◽  
pp. 1416-1421 ◽  
Author(s):  
Gang Xue

Simple-supported reinforced concrete (R.C) beams are subjected to an increasing static load in the middle to introduce cracks, and the last load step corresponds to failure. After each load step and unloading, an experimental dynamic monitoring is performed. Multiple degree freedom dynamic equation of the test beams is wavelet transformed, and structural dynamic response expression on multi-scale is acquired. It’s shown that multi-scale decomposition of signal comprises more structural damage information. By means of DASP signal processing system, binary wavelet transformation is applied to dynamic signal of reinforced concrete beams on different damage state. Through analyzing wave-figure of all frequency scales, the damage of reinforced concrete beams is detected.

2012 ◽  
Vol 446-449 ◽  
pp. 566-571
Author(s):  
Jia Quan Wu ◽  
Ji Yao ◽  
Hong Yan Li ◽  
Liang Cao ◽  
Kun Ma

This paper describes the strain mode damage detection theory and a three-dimensional reinforced concrete beams finite element model was built by finite element software. The different degree injury models tests were compared. Experiment’s results show that the first four natural frequencies of different degree injury models are small differences while the corresponding strain modes have a significant changed in damage location. The structure of the strain mode changes are still evident when structural damage occurred in the strain mode node.


2016 ◽  
Vol 845 ◽  
pp. 140-147
Author(s):  
Fadillawaty Saleh

This paper presents a numerical algorithm technique to detect cracks propagated in concrete beams based on the frequency response curve of the beam determined from vibration testing. Impact tests on simply supported reinforced concrete beams were conducted to measure vibration on the beam. The ICATS software was carried out to capture the Frequency Response Functions (FRFs) data at each load step. Utilizing the FRFs data, a numerical algorithm based on finite different methods was performed to compute the different FRFs between undamage and damage beams based on the mode shape curvature square (MSCS) method. The numerical damage location was defined by subtracting the MSCS undamage to damage of beams. Therefore, the accurate damage location was identified by comparing the numerical and observed experimental results.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Liye Zhang ◽  
Limin Sun ◽  
Lijuan Dong

Due to many nondamage factors such as temperature, humidity, carbonation, and corrosion effects on natural frequency, the key problem of the application frequency-based method to detect damage is to reveal the rules of these factors affect natural frequency and further to eliminate their effects. The long-term characteristics of reinforced concrete structures require a lot of attention, especially in corrosive environment. In this paper, an experimental investigation was conducted to study the deflection and natural frequency of reinforced concrete beam in a marine environmental chamber for six corrosion stages (accelerated corrosion for 0, 20, 40, 70, 100, and 140 days). The experimental results demonstrated that deflection increases with corrosion time, while natural frequency decreases with corrosion time. Based on the accelerate corrosion test data of reinforced concrete beams, the general expression of the relationship between corrosion depth and natural frequency has been established through the fitting curve method. The polynomial model has been selected for establishing the relationship between steel corrosion depth (including the main reinforcement and stirrup) and natural frequency. The reason for selecting the polynomial model is that the sum of squares due to error (SSE) is closer to 0 and the coefficient of multiple determination (R-square) is closer to 1. This investigations help to discriminate the cause of reinforced concrete beams natural frequency change, to eliminate nondamage factors affects, and to apply many structural damage identification methods effectively.


Author(s):  
B. Goszczyńska ◽  
G. Świt ◽  
W. Trąmpczyński

Abstract The study presents the analysis of the process of crack formation and crack width growth in statically determinate and hyperstatic reinforced concrete beams with the IADP acoustic emission method. The beams were subjected to the monotonic, variable with unloading, and variable cyclic loading schemes. The criteria of structural damage were established to account for the structure durability


2019 ◽  
Vol 110 ◽  
pp. 01053
Author(s):  
Alexandr Shilov ◽  
Petr Polskoy ◽  
Dmitriy Mailyan ◽  
Petr Shilov

In the theory of reinforced concrete, the issue on strength of the oblique beam sections is more complicated than that on the standard sections, since it depends on many factors. The change of at least one of them leads to a significant change in the carrying capacity and in the structural damage pattern. This is due to the fact that at the operating level of the load, all conventional reinforced concrete structures work with cracks, which must be considered in the calculation. However, in the existing regulatory documents and public sources, this issue is not specified. This paper considers the effect of initial cracks on the strength of oblique cross sections of the reinforced concrete beams strengthened with carbon fiber. The experimental studies results obtained through the transverse force testing of forty-two prototypes made of heavy concrete of B30 design grade are presented. The test samples had initial oblique cracks of 0.6-0.9 mm width and were reinforced with three composite U stirrups from the fabric based on unidirectional carbon fibers in the shear span. Initial cracks in the beams were formed at three values of the shear span – 1.5h0, 2h0 and 2.5h0. The test data show the impact of initial cracks on the efficiency of composite reinforcement of oblique cross sections of the prototypes at various values of shear spans.


2014 ◽  
Vol 12 (10) ◽  
pp. 363-377 ◽  
Author(s):  
Esayas Gebreyouhannes ◽  
Taiju Yoneda ◽  
Tetsuya Ishida ◽  
Koichi Maekawa

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