scholarly journals Temporal Acoustic Emission Index for Damage Monitoring of RC Structures Subjected to Bidirectional Seismic Loadings

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2804 ◽  
Author(s):  
Chihab Abarkane ◽  
Francisco J. Rescalvo ◽  
Jesús Donaire-Ávila ◽  
David Galé-Lamuela ◽  
Amadeo Benavent-Climent ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Damage Index ◽  
Shaking Table ◽  
Ground Acceleration ◽  
Level Indicator ◽  
Rc Structures ◽  
Damage Level ◽  
Seismic Loadings ◽  
Plastic Strain Energy ◽  
In The Beginning

This paper shows the acoustic emission (AE) analysis recorded during the loading process of reinforced concrete (RC) structures subjected to bidirectional seismic loadings. Two waffle plates (bidirectional) supported by isolated square columns were tested on a shaking table with a progressive and increasing ground acceleration until the final collapse. Each specimen was subjected to a different loading history. A relevant delay in the beginning of the significant AE energy is observed as the peak value of the ground acceleration increases. Based on this result, a new AE temporal damage index (TDI), defined as the time difference between the onset of the significant AE activity and the onset of the loading that causes this AE activity, is proposed and validated by comparing it with the plastic strain energy released by the concrete, typically used as a reliable damage level indicator. Good agreement was observed for both specimens and seismic inputs.

Discrimination of Acoustic Emission Signals for Damage Assessment in a Reinforced Concrete Slab Subjected to Seismic Simulations

2013 ◽  
Vol 38 (3) ◽  
pp. 303-310 ◽  
Author(s):  
Francisco A. Sagasta ◽  
Juan L. Torné ◽  
Antonio Sánchez-Parejo ◽  
Antolino Gallego
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Mechanical Energy ◽  
Low Frequency ◽  
Shaking Table ◽  
Reinforced Concrete Slab ◽  
Rc Structures ◽  
Steel Columns ◽  
Ae Signals

Abstract The purpose of this work is to distinguish between Acoustic Emission (AE) signals coming from mechanical friction and AE signals coming from concrete cracking, recorded during fourteen seismic simulations conducted with the shaking table of the University of Granada on a reinforced concrete slab supported on four steel columns. To this end, a particular criterion is established based on the Root Mean Square of the AE waveforms calculated in two different temporal windows. This criterion includes a parameter calculated by optimizing the correlation between the mechanical energy dissipated by the specimen (calculated by means of measurements with accelerometers and displacement transducers) and the energy obtained from the AE signals recorded by low-frequency piezoelectric sensors located on the specimen. The final goal of this project, initiated four years ago, is to provide a reliable evaluation of the level of damage of Reinforced Concrete specimens by means of AE signals to be used in future Structural Health Monitoring strategies involving RC structures.

scholarly journals Fragility estimation for global building classes using analysis of the Cambridge earthquake damage database (CEQID)

2021 ◽  
Author(s):  
Robin Spence ◽  
Sandra Martínez-Cuevas ◽  
Hannah Baker
Keyword(s):  
Fragility Curves ◽  
Resistance Index ◽  
Earthquake Damage ◽  
Ground Acceleration ◽  
Damage Level ◽  
Ground Motion Parameter ◽  
Geographical Regions ◽  
Concrete Building ◽  
Damage Data ◽  
Regional Comparisons

AbstractThis paper describes CEQID, a database of earthquake damage and casualty data assembled since the 1980s based on post-earthquake damage surveys conducted by a range of research groups. Following 2017–2019 updates, the database contains damage data for more than five million individual buildings in over 1000 survey locations following 79 severely damaging earthquakes worldwide. The building damage data for five broadly defined masonry and reinforced concrete building classes has been assembled and a uniform set of six damage levels assigned. Using estimated peak ground acceleration (PGA) for each survey location based on USGS Shakemap data, a set of lognormal fragility curves has been developed to estimate the probability of exceedance of each damage level for each class, and separate fragility curves for each of five geographical regions are presented. A revised set of fragility curves has also been prepared in which the bias in the curve resulting from the uncertainty in the ground motion parameter has been removed. The uncertainty in the fragility curves is evaluated and discussed and the curves are compared with those from other studies. A resistance index for each class of building is developed and cross-regional comparisons using this resistance index are presented.

scholarly journals Performance of an Existing Reinforced Concrete Building Designed in Accordance to Older Indonesian Seismic Code: A Case Study for a Hotel in Kupang, Indonesia

2018 ◽  
Vol 20 (1) ◽  
pp. 35
Author(s):  
Pamuda Pudjisuryadi ◽  
Benjamin Lumantarna ◽  
Ryan Setiawan ◽  
Christian Handoko
Keyword(s):  
Plastic Hinge ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Seismic Load ◽  
Ground Acceleration ◽  
Seismic Code ◽  
Damage Level ◽  
History Analysis ◽  
Nonlinear Time History ◽  
Seismic Hazard Map

The recent seismic code SNI 1726-2012 is significantly different compared to the older code SNI 1726-2002. The seismic hazard map was significantly changed and the level of maximum considered earthquake was significantly increased. Therefore, buildings designed according to outdated code may not resist the higher demand required by newer code. In this study, seismic performance of Hotel X in Kupang, Indonesia which was designed based on SNI-1726-2002 is investigated. The structure was analyzed using Nonlinear Time History Analysis. The seismic load used was a spectrum consistent ground acceleration generated from El-Centro 18 May 1940 North-South component in accordance to SNI 1726-2012. The results show that Hotel X can resist maximum considered earthquake required by SNI 1726-2012. The maximum drift ratio is 0.81% which is lower than the limit set by FEMA 356-2000 (2%). Plastic hinge damage level is also lower than the allowance in ACMC 2001.

scholarly journals Numerical Analysis of an Earthen Masonry Structure Subjected to Blast Loading

CivilEng ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 969-985
Author(s):  
Demiana Tse ◽  
João M. Pereira ◽  
Paulo B. Lourenço
Keyword(s):  
Damage Index ◽  
Damage Threshold ◽  
Impulsive Loading ◽  
World Heritage Site ◽  
Unesco World Heritage ◽  
Damage Level ◽  
Heritage Site ◽  
Pressure Profiles ◽  
Unesco World Heritage Site ◽  
Explicit Dynamic

Historic monuments and construction capture the knowledge of civilizations of the past and are a source of pride for people of the present. Over the centuries, these buildings have been at risk from natural and man-made causes. The Alhambra, a UNESCO World Heritage Site in Granada, Spain, is one of such places. This paper aims to evaluate the structural performance of the Torre de la Vela, a tower in the Alhambra, under blast loads. The loads were based on historical records of barrels of gunpowder and were modeled as simplified pressure profiles using existing empirical equations. The effect of impulsive loading on the material properties was accounted for using dynamic increase factors, determined experimentally by previous authors. The model was created using finite element methods (FEM) and the problem was solved using explicit dynamic analysis available in Abaqus/Explicit. Using the failure volume damage index, a blast load applied outside and inside of the building would create a low damage level, which should be treated with caution given the occurrence of localized damage. The removal of elements exceeding a given damage threshold led to more visible damage patterns than the Concrete Tension Damage option in Abaqus.

scholarly journals Time-Dependent Damage Estimation of a High-Rise Steel Building Equipped with Buckling-Restrained Brace under a Series of Earthquakes and Winds

2021 ◽  
Vol 11 (19) ◽  
pp. 9253
Author(s):  
Ahmad Naqi ◽  
Tathagata Roy ◽  
Taiki Saito
Keyword(s):  
Damage Index ◽  
Cumulative Damage ◽  
Structural Elements ◽  
High Rise ◽  
Sequence Of Events ◽  
Design Life ◽  
Steel Building ◽  
Element Approach ◽  
Wind Events ◽  
Plastic Strain Energy

This study investigates the cumulative damage of a 20-story high-rise steel building equipped with buckling-restrained braces (BRB) under the likely occurrence of earthquake and wind events in the design life of the building. The objective of this research is to introduce a method for evaluating the cumulative damage of BRBs under multi-hazard events that are expected to occur during the service life of a high-rise building in order to achieve a safer building. A methodology is proposed using a Poisson point process to estimate the timeline of earthquake and wind events, wherein the events are assumed to be independent in nature. The 20-story high-rise steel building with BRBs is designed according to the Japanese standard and analyzed using the finite element approach, considering nonlinearities in the structural elements and BRBs. The building is analyzed consecutively using the timeline of earthquakes and winds, and the results are compared with those under individual earthquakes and winds. In addition to the responses of the frame such as the floor displacement and acceleration, the damage of BRBs in terms of the damage index, the energy absorption, the plastic strain energy, and the maximum and cumulative ductility factor are evaluated. It is observed that the BRB’s fatigue life under multi-hazard scenarios is a multi-criteria issue that requires more precise investigation. Moreover, the overall building’s performance and BRB’s cumulative damage induced by the sequence of events in the design life of the building is significantly larger than that under an individual event.

scholarly journals Damage Source Identification of Reinforced Concrete Structure Using Acoustic Emission Technique

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Alireza Panjsetooni ◽  
Norazura Muhamad Bunnori ◽  
Amir Hossein Vakili
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Nondestructive Evaluation ◽  
Analysis Method ◽  
Reinforced Concrete Structure ◽  
Acoustic Emission Technique ◽  
Rc Structures ◽  
Rc Frames ◽  
Damage Monitoring ◽  
Investigation Process

Acoustic emission (AE) technique is one of the nondestructive evaluation (NDE) techniques that have been considered as the prime candidate for structural health and damage monitoring in loaded structures. This technique was employed for investigation process of damage in reinforced concrete (RC) frame specimens. A number of reinforced concrete RC frames were tested under loading cycle and were simultaneously monitored using AE. The AE test data were analyzed using the AE source location analysis method. The results showed that AE technique is suitable to identify the sources location of damage in RC structures.

Performance of Multifiber Beam Element for Seismic Analysis of Reinforced Concrete Structures

2014 ◽  
Vol 14 (06) ◽  
pp. 1450013 ◽  
Author(s):  
Xuan Huy Nguyen
Keyword(s):  
Reinforced Concrete ◽  
Damage Mechanics ◽  
Seismic Analysis ◽  
Axial Strain ◽  
Nonlinear Behavior ◽  
Bending Moment ◽  
Axial Direction ◽  
Beam Element ◽  
Shaking Table ◽  
Rc Structures

This paper presents a simplified modeling strategy for simulating the nonlinear behavior of reinforced concrete (RC) structures under seismic loadings. A new type of Euler–Bernoulli multifiber beam element with axial force and bending moment interaction is introduced. To analyze the behavior of RC structures in the axial direction, the interpolation of the axial strain is enriched using the incompatible modes method. The model uses the constitutive laws based on plasticity for steel and damage mechanics for concrete. The proposed multifiber element is implemented in the finite element Code_Aster to simulate the nonlinear behavior of two different RC structures. One structure is a building tested on a shaking table; the other is a column subjected to cyclic loadings. The comparison between the simulation and experimental results shows that the performance of this approach is quite good. The proposed model can be used to investigate the behavior of a wider variety of configurations which are impossible to study experimentally.

Damage detection using wavelet entropy of acoustic emission waveforms in concrete under flexure

2020 ◽  
pp. 147592172095709
Author(s):  
Nitin Burud ◽  
JM Chandra Kishen
Keyword(s):  
Acoustic Emission ◽  
Wavelet Transform ◽  
Time Domain ◽  
Fracture Process ◽  
Damage Index ◽  
Relative Energy ◽  
Wavelet Entropy ◽  
Complex Fracture ◽  
The Time Domain ◽  
Entropy Formulation

This work dives into the spectral realm of acoustic emission waveforms. The acoustic emission waveforms carry a footprint of source, its mechanism, and the information of the medium through which it travels. The idiosyncrasies of these waveforms cannot be visualized from the time-domain parameters. The complex fracture process of the heterogeneous composite, such as concrete, reflects in the spectral disorder of acoustic emission signals. The use of wavelet entropy is proposed to estimate the spectral disorder. To evaluate wavelet entropy, the relative energy distribution in frequency sub-bands is determined using the wavelet transform. The Shannon entropy formulation as a wavelet entropy is utilized for discriminating spatiotemporally distributed acoustic emission events according to their respective level of disorder. The possible twofold application of the wavelet entropy as a signal discriminator and a damage index is qualitatively demonstrated. The increase in the statistical variance of wavelet entropy distribution with the increase in stress level reveals the presence of multi-sources as well as multi-mechanistic fracture process.

scholarly journals Effect of Soil Box Boundary Conditions on Dynamic Behavior of Model Soil in 1 g Shaking Table Test

2020 ◽  
Vol 10 (13) ◽  
pp. 4642
Author(s):  
Hoyeon Kim ◽  
Daehyeon Kim ◽  
Yonghee Lee ◽  
Haksung Kim
Keyword(s):  
Boundary Conditions ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Boundary Effects ◽  
Soil Behavior ◽  
Ground Acceleration ◽  
Various Boundary Conditions ◽  
Model Soil ◽  
Shear Box ◽  
Laminar Shear

In order to evaluate the effects of soil box boundary conditions on the dynamic soil behavior, the Rigid Box (RB) and the Laminar Shear box (LSB) were constructed and 1 g shaking table tests were carried out for various boundary conditions. The boundary effects of the RB and the LSB were compared. To reduce the boundary effects of the RB, sponges, 5 cm, 10 cm, and 15 cm in thickness, were attached to the two end sides of the RB. A model soil was constructed on flat ground, and the acceleration and amplification occurring in the center of the soil were analyzed by spectrum and peak ground acceleration. Compared with the RB, the center and wall accelerations of LSB were very close to each other. This implies that the LSB can better simulate the behavior of the infinite half space than the RB.

scholarly journals Monitoring of reinforced concrete short ties with the acoustic emission technique

2019 ◽  
Vol 281 ◽  
pp. 04001
Author(s):  
Djillali Mezhoud ◽  
Jacqueline Saliba
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Structural Integrity ◽  
Tensile Tests ◽  
Average Frequency ◽  
Rc Structures ◽  
Surrounding Matrix ◽  
High Adhesion ◽  
Damage Process ◽  
Different Characteristics

Cracking in Reinforced Concrete (RC) structures may impact their durability and their structural integrity. Cracking is mainly influenced by stress distribution along the interface between steel and concrete. Thus, quantitative evaluation of steel-concrete bond, which is responsible of transferring load from steel bar to the surrounding matrix, and its effect on fracture properties is of major important. An experimental investigation on RC ties is reported in this paper. Tensile tests have been conducted on cubic specimens with different high adhesion reinforcement diameters. Those tests have been monitored continuously using the Acoustic Emission (AE) technique for a better evaluation of the damage process. The results show a good correlation between the load and the AE activity. AE signals with different characteristics have been observed during the different fracture stages. Parameters such as duration and energy increased with the loading level and can be used as indicators to detect the macrocracking of concrete. A parametric analysis is performed between average frequency and RA value. Ib-value of AE hits has been also investigated and decreases to 0.12 prior to the first macro crack.

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