scholarly journals Application of Acoustic Emission Technique for Bond Characterization in FRP-Masonry Systems

2014 ◽  
Vol 624 ◽  
pp. 534-541 ◽  
Author(s):  
Bahman Ghiassi ◽  
Els Verstrynge ◽  
Paulo B. Lourenço ◽  
Daniel V. Oliveira
Keyword(s):  
Acoustic Emission ◽  
Failure Mode ◽  
Failure Modes ◽  
Clear Distinction ◽  
Acoustic Emission Technique ◽  
Emission Data ◽  
Bond Behavior ◽  
Damage Propagation ◽  
Lap Shear ◽  
Bond Tests

The acoustic emission (AE) technique is used for investigating the interfacial fracture and damage propagation in GFRP-and SRG-strengthened bricks during debonding tests. The bond behavior is investigated through single-lap shear bond tests and the fracture progress during the tests is recorded by means of AE sensors. The fracture progress and active debonding mechanisms are characterized in both specimen types with the aim of AE outputs. Moreover, a clear distinction between the AE outputs of specimens with different failure modes, in both SRG-and GFRP-strengthened specimens, is found which allows characterizing the debonding failure mode based on acoustic emission data.

Bond Behaviour of FRCM Composites: Effects of High Temperature

2019 ◽  
Vol 817 ◽  
pp. 161-166
Author(s):  
Antonio Iorfida ◽  
Sebastiano Candamano ◽  
Fortunato Crea ◽  
Luciano Ombres ◽  
Salvatore Verre ◽  
...  
Keyword(s):  
High Temperature ◽  
Failure Mode ◽  
Failure Modes ◽  
Construction Materials ◽  
Mechanical Damage ◽  
High Density ◽  
Bond Behaviour ◽  
Bond Slip ◽  
Masonry Construction ◽  
Lap Shear

The fire remains one of the serious potential risks to most buildings and structures, as recently it’s been witnessed in Paris’ historic Notre Dame Cathedral and London’s Grenfell Tower. Concrete and masonry construction materials suffer physiochemical changes and mechanical damage caused by heating that is usually confined to the outer surface but can eventually compromise their load-bearing capacity. FRCM systems could provide when applied, supplemental fire insulation on pre-existing structural members, but there is a lack of knowledge about their properties in those conditions. This experimental work, thus, aims to evaluate the mechanical behaviour of carbon-FRCM and basalt-FRCM composites bonded to masonry substrate after high temperature exposure. Temperatures of 100 °C, 300 °C and 500 °C over a period of three hours were used to investigate the degradation of their mechanical properties. Single lap shear bond tests were carried out to evaluate the bond-slip response and failure modes. For all the tested temperatures higher peak stresses were measured for carbon-FRCM composite than basalt ones. Furthermore, low-density basalt-FRCM composite showed higher peak stresses and lower global slips up to 300 °C than high-density one. Carbon-FRCM composite failure mode was not effected by temperature. High-density basalt-FRCM composite showed a change in failure mode between 300 °C and 500 °C.

scholarly journals Multiparameter Approach for Damage Propagation Analysis in Fiber-Reinforced Polymer Composites

2021 ◽  
Vol 11 (1) ◽  
pp. 393
Author(s):  
Claudia Barile ◽  
Caterina Casavola ◽  
Giovanni Pappalettera ◽  
Paramsamy Kannan Vimalathithan
Keyword(s):  
Acoustic Emission ◽  
Damage Evolution ◽  
Principal Component ◽  
Fiber Reinforced Polymer ◽  
Sound Waves ◽  
Fiber Reinforced ◽  
Evaluation Tool ◽  
Damage Propagation ◽  
Lap Shear ◽  
Reinforced Polymer

Assessing the damage evolution in carbon-fiber-reinforced polymer (CFRP) composites is an intricate task due to their complex mechanical responses. The acoustic emission technique (AE) is a non-destructive evaluation tool that is based on the recording of sound waves generated inside the material as a consequence of the presence of active defects. Proper analysis of the recorded waves can be used for monitoring the damage evolution in many materials, including composites. The acoustic track associated with the entire loading history of the sample or the structures is usually followed by using some descriptors, such as the amplitude of the sound waves and the number of counts. In this study, the acoustic emission in CFRP single-lap shear joints was monitored by using a multiparameter approach based on the contemporary analysis of multiple features, such as the absolute signal level (ASL), initiation frequency, and reverberation frequency, to understand whether a proper combination of them can be adopted for a more robust description of the damage propagation in CFRP structures. For selecting the best features, principal component analysis (PCA) was used. The selected features were classified into different clusters using fuzzy c-means (FCM) data clustering for analyzing the damage modes.

scholarly journals Flexural Characteristics Evaluation for Reinforced Concrete Affected by Steel Corrosion Based on an Acoustic Emission Technique

2019 ◽  
Vol 9 (8) ◽  
pp. 1640 ◽  
Author(s):  
Zhang ◽  
Tan ◽  
Wang ◽  
Cheng ◽  
Yang ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Failure Modes ◽  
Steel Corrosion ◽  
Test Method ◽  
Rc Beam ◽  
Acoustic Emission Technique ◽  
Statistical Parameters ◽  
Dense Distribution ◽  
Ae Signals

The purpose of this research is to utilize a more advanced test method for investigating the effect of steel corrosion on the flexural characteristics of a reinforced concrete (RC) beam on a microscopic cracking level. Firstly, over-reinforced RC beam specimens were prepared and corroded using an electrical accelerated steel corrosion setup in different ratios. Subsequently, bending and acoustic emission (AE) tests were performed on all the specimens to obtain their ultimate flexural loads, failure modes and AE signals. Furthermore, rise time/peak amplitude (R/A), ringing counts/duration (AF) and improved b (Ib) values, as the statistical parameters of AE signals, were calculated for indicating the transformation of RC specimens’ crack modes and failure modes under the effect of steel corrosion. Finally, the locations of AE events were obtained by localization technology and compared with the locations of concrete cracks (cracks map). The results revealed that the ultimate flexural load decreases with steel corrosion. The crack tends to transform from shear- to tensile-type along with the increase of the steel corrosion ratio. The trend of the Ib-value curve can reflect the formation and development of cracks; and the larger the duration of violent fluctuations in the Ib-value curve is, the larger the ultimate flexural load of the RC beam is. The region where the crack is located can be judged by the position where the relatively dense distribution of the AE events is.

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