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Damage assessment of reinforced concrete beam with various depths by using acoustic emission technique

Damage assessment of reinforced concrete beam with various depths by using acoustic emission technique / Majed A. A. Aldahdooh
Penyelidikan ini adalah bertujuan untuk menggunakan Acoustic Emssion (AE) di dalam sistem pemantauan struktur kesihatan. Tiga kategori rasuk konkrit bertetulang dibina dengan perbezaan kedalaman rasuk dan setiap kategori mengandungi empat sampel dengan jumlah keseluruhannya 12 rasuk konkrit bertetulang. Semua sampel kajian diuji dengan mengenakan pembebanan lentur empat titik dan dikelaskan kepada pembebanan monotonik dan berperingkat. Di dalam kajian ini, setiap kategori rasuk konkrit bertetulang akan diuji dengan satu rasuk dikenakan bebanan monotonik dan selebihnya bebanan berperingkat. Berdasarkan pemantauan secara kasar, keseluruhan sampel ini mengalami mod kegagalan lentur, dan untuk mengumpul dan merekod kesemua isyarat AE data yang terlibat di dalam kajian ini, sensor jenis R6I dan sistem AE Digital MICRO-SAMOS (μSAMOS) digunakan bersama dengan perisian computer AEwin untuk menganalisis data. Selain itu, pengamatan secara visual juga dilaksanakan bagi membandingkan hasil analisis oleh AE. Objektif utama dalam kajian ini adalah untuk menyelidik dan mengkaji kebolehan AE dalam menentukan lokasi keretakan pada rasuk selain daripada mengkaji tenaga mutlak kumulatif untuk perilaku mekanikal yang berbeza bagi keretakan tersebut. Di samping itu, kaedah Intensity Analysis (IA) digunakan bagi menentukan tahap kerosakan dan kegagalan lentur pada rasuk berkenaan. Hasil penyelidikan ini mendapati bahawa teknik AE mampu menentukan dengan tepat lokasi keretakan mikro yang tidak dapat dilihat dengan mata kasar dan keretakan makro secara visual. Julat perbezaan adalah diantara 25mm dan 55mm. Berdasarkan kajian ini, didapati keretakan mikro akan terjadi apabila tenaga mutlak kumulatif melebihi 1.0 x 106 atto joule. Kesimpulanya penyelidikan ini mencapai objektif sebenar. _______________________________________________________________________________________________________ This study aimed at using the Acoustic Emission (AE) in Structure Health Monitoring (SHM), since three categories of reinforced concrete (RC) beams (a total of 12 RC beams) with difference depth of beams. The study sample were tested in four-point bending setup under monotonic and stepwise loading, each category of RC beams contained four beams, one beam for monotonic loading and three beams for stepwise loading. All beams encountered flexural failure mode. In collecting the AE data, MICRO -SAMOS (μSAMOS) Digital AE system and R6I sensor were used, as AEwin software was used to analyze the data. Moreover, visual observation was conducted to compare with the AE results. The main interest of this research was to investigate the capability of AE in locating the concrete specimen’s cracks besides investigating the cumulative absolute energy for different mechanical behaviors of those cracks. On the other hand, Intensity Analysis (IA) method was used to quantified the damage level of the RC-beams associated with the crack flexural failure. The proposed method introduced that the differences of crack locations between visual observation and AE sources are between 25mm and 55mm. Also by comparing the visual observation to the AE result, when the cumulative absolute energy exceeds 1.0 x 106 attoJoule (aJ), the onset of the first crack occurs, and the recommended action at this stage is typically minor surface defects. Moreover, when the specimens affected by localization damage, the absolute energy increases dramatically for about five to seven times.
Contributor(s):
Majed A. A. Aldahdooh - Author
Primary Item Type:
Thesis
Identifiers:
Accession Number : 875000508
Language:
English
Subject Keywords:
Acoustic Emission (AE); Structure Health Monitoring (SHM); reinforced concrete (RC) beams
First presented to the public:
6/1/2011
Original Publication Date:
6/5/2018
Previously Published By:
Universiti Sains Malaysia
Place Of Publication:
School of Civil Engineering
Citation:
Extents:
Number of Pages - 106
License Grantor / Date Granted:
  / ( View License )
Date Deposited
2018-06-05 10:47:01.691
Date Last Updated
2019-01-07 11:24:32.9118
Submitter:
Mohd Jasnizam Mohd Salleh

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Damage assessment of reinforced concrete beam with various depths by using acoustic emission technique1 2018-06-05 10:47:01.691