scholarly journals Developing a Feature Extraction of Existing Structures Using an Ambient Vibration Test

2020 ◽  
Author(s):  
Hamed Sarmast
Keyword(s):  
Experimental Data ◽  
Feature Extraction ◽  
Dynamic Properties ◽  
Analytical Models ◽  
Ambient Vibration ◽  
Vibration Test ◽  
Vibration Testing ◽  
Ambient Vibration Test ◽  
Existing Structures ◽  
Ambient Vibration Testing

The paper aims to extract the dynamic properties of existing structures without utilizing the analytical models. The ambient vibration testing could be used on any type of frame such as concrete, steeland masonry to investigate the structural vulnerability.The method could bethe first stage and necessarily forthe retrofit process. To achieve this aim, the ambient vibration testing can also be employed. The experimental data obtained from the methodcan be used to monitor the health, evaluating, and damage detection structures at present. The achieved datacan be comparedin future with the recorded signals at different times.

scholarly journals Developing a Feature Extraction of Existing Structures Using an Ambient Vibration Test

2020 ◽  
Author(s):  
Hamed Sarmast ◽  
Hassan Haji Kazemi
Keyword(s):  
Dynamic Properties ◽  
Analytical Models ◽  
Ambient Vibration ◽  
Vibration Test ◽  
Vibration Testing ◽  
Destructive Testing ◽  
Ambient Vibration Test ◽  
Existing Structures ◽  
Ambient Vibration Testing ◽  
Using Data

The paper aims to extract the dynamic properties of existing structures without utilizing the analytical models. The ambient vibration testing could be used on any type of frame such as concrete, steel and masonry to investigate the structural vulnerability. The method could be the first stage and necessarily for the retrofit process. To achieve this aim, the ambient vibration testing can also be employed. The experimental data obtained from the method can be used to monitor the health, evaluating, and damage detection structures at present. The achieved data can be compared in future with the recorded signals at different times. So, the ambient vibration test was carried out on the building of Imam Hossein Hospital at Mashhad. Then, its dynamic characteristics of the acceleration records are obtained by using Data Acquisition System with three accelerometers in two perpendicular coordinates. The method is more accurate and practical compare with analytical models of the existing buildings. The ambient vibration test prevents of several points such as destructive testing or may irreparable damage to the building as well as high cost. Even, the ambient vibration test maybe required for every couple of decayed, when noticed of any changes in the condition of buildings after construction. These type of changes could be quality of concrete or welding or some changes in the location of walls that can be affected the dynamic specifications of the building. The method provides real lateral load pattern and actual modes that can evaluate existing condition of the building compare with the time of construction.

Structural System Identification of Elevated Steel Water Tank Using Ambient Vibration Test and Calibration of Numerical Model

2020 ◽  
Vol 20 (10) ◽  
pp. 2071010
Author(s):  
Mohammad Alembagheri ◽  
Maria Rashidi ◽  
Mohammad Seyedkazemi
Keyword(s):  
System Identification ◽  
Numerical Model ◽  
Dynamic Properties ◽  
Ambient Vibration ◽  
Water Tank ◽  
Ambient Vibration Test ◽  
Vibration Data ◽  
Steel Material ◽  
Ambient Vibration Testing ◽  
Structural System Identification

This research aims to investigate the feasibility of using ambient vibration testing for system identification of an elevated water tank. To identify the natural dynamic properties, the experimental study is carried out on an elevated steel water tank located in Tehran. The tank is instrumented with a sensitive velocimeter sensor (microtremor), and the ambient velocity of the tank is recorded for 30[Formula: see text]min in three orthogonal axes. Employing the peak-picking method in the frequency domain, the fundamental frequency of the tank is determined as about 1.9[Formula: see text]Hz. Then, the numerical model of the tank is generated and calibrated based on the obtained data. In the primary modeling, the values of natural frequencies of the tank are in good agreement with the results of the ambient vibration data. This finding is judged to be reasonable considering no clear sign of corrosion in the steel material.

Bayesian model updating of a 20-story office building utilizing operational modal analysis results

2019 ◽  
Vol 22 (16) ◽  
pp. 3385-3394
Author(s):  
Heung Fai Lam ◽  
Jun Hu ◽  
Mujib Olamide Adeagbo
Keyword(s):  
Bayesian Model ◽  
Structural Model ◽  
Model Updating ◽  
Dynamic Properties ◽  
Ambient Vibration ◽  
Modal Parameters ◽  
Vibration Test ◽  
Ambient Vibration Test ◽  
Building Model ◽  
Shear Building

Most existing buildings are not equipped with long-term monitoring system. For the structural model updating and damage detection of this type of structures, ambient vibration test is popular as artificial excitation is not required. This article presents in detail the full-scale ambient vibration test, operational modal analysis, and model updating of a tall building. To capture the dynamic properties of the target 20-story building with limited number of sensors, a 15-setup ambient vibration test was designed to cover at least three measurement points (each consists of a vertical and two orthogonal horizontal measured degrees of freedom) for each selected floor. The modal parameters of each setup were extracted from the measured acceleration signals using a frequency domain decomposition method and were combined to form the global mode shape through the least-squares method. Due to the regularity of the building, a simple class of shear building models was employed to capture the dynamic characteristics of the building under lateral vibration. The identified modal parameters of the building were employed for the model updating of the shear building model to identify the distribution of inter-story stiffness. Since the “amount” of the measured information is small when compared to the “amount” of required information for identifying the uncertain parameters, the model updating problem is unidentifiable. To handle this problem, the Markov chain Monte Carlo–based Bayesian model updating method is employed in this study. The identified modal parameters revealed interesting features about the dynamic properties of the building. The well-matched results between model-predicted and identified modal parameters show the validity of the shear building model in this case study. This study provides valuable experience in the area of structural model updating and structural health monitoring.

Retrofitting Effect on the Dynamic Properties of Model-Arch Dam with and without Reservoir Water Using Ambient-Vibration Test Methods

2016 ◽  
Vol 142 (10) ◽  
pp. 04016069 ◽  
Author(s):  
Ahmet Can Altunişik ◽  
Murat Günaydin ◽  
Barış Sevim ◽  
Alemdar Bayraktar ◽  
Süleyman Adanur
Keyword(s):  
Dynamic Properties ◽  
Test Methods ◽  
Arch Dam ◽  
Ambient Vibration ◽  
Vibration Test ◽  
Reservoir Water ◽  
Ambient Vibration Test

scholarly journals The Health Monitoring Method of Concrete Dams Based on Ambient Vibration Testing and Kernel Principle Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Lin Cheng ◽  
Jie Yang ◽  
Dongjian Zheng ◽  
Bo Li ◽  
Jie Ren
Keyword(s):  
Health Monitoring ◽  
Structural Damage ◽  
Dynamic Properties ◽  
Ambient Vibration ◽  
Modal Parameters ◽  
Observation System ◽  
Concrete Dams ◽  
Vibration Testing ◽  
Monitoring Method ◽  
Ambient Vibration Testing

The ambient vibration testing (AVT) measurement of concrete dams on full-scale can show the practical dynamic properties of structure in the operation state. For most current researches, the AVT data is generally analyzed to identify the structural vibration characteristics, that is, modal parameters. The identified modal parameters, which can provide the global damage information or the damage location information of structure, can be used as the basis of structure health monitoring. Therefore, in this paper, the health monitoring method of concrete dams based on the AVT is studied. The kernel principle analysis (KPCA) based method is adopted to eliminate the effect of environmental variables and monitor the health of dam under varying environments. By taking full advantage of the AVT data obtained from vibration observation system of dam, the identification capabilities and the warning capabilities of structural damage can be improved. With the simulated AVT data of the numerical model of a concrete gravity dam and the measured AVT data of a practical engineering, the performance of the dam health monitoring method proposed in this paper is verified.

scholarly journals Ambient Vibration Test of a 18-Story Reinforced Concrete Building

2018 ◽  
Vol 53 ◽  
pp. 03077
Author(s):  
Jun Ma ◽  
Jie Ge
Keyword(s):  
Reinforced Concrete ◽  
Domain Decomposition ◽  
Frequency Domain ◽  
Dynamic Properties ◽  
Ambient Vibration ◽  
Vibration Test ◽  
Ambient Vibration Test ◽  
Reinforced Concrete Building ◽  
Concrete Building ◽  
Frequency Domain Decomposition

Ambient vibration analysis of a 18-story reinforced concrete building was carried out to investigate its dynamic properties. Ambient vibration test was conducted on the building, and modal parameters including natural frequencies and damping ratios were identified using the Frequency domain decomposition (FDD) method and the Enhanced frequency domain decomposition (EFDD) method. The results demonstrate that ambient vibration test is a feasible and efficient technique to excite structures, and that FDD and EFDD methods are reliable and efficient techniques for ambient vibration data.

Operational Modal Analysis and Bayesian Model Updating of a Coupled Building

2018 ◽  
Vol 19 (01) ◽  
pp. 1940012
Author(s):  
Jun Hu ◽  
Jia-Hua Yang
Keyword(s):  
Bayesian Model ◽  
Main Part ◽  
Structural Model ◽  
Model Updating ◽  
Dynamic Properties ◽  
Ambient Vibration ◽  
Modal Parameters ◽  
Vibration Test ◽  
Ambient Vibration Test ◽  
Complementary Part

This paper reports the step-by-step procedures of a full-scale ambient vibration test and the corresponding modal identification and Bayesian structural model updating of a coupled building. The building is characterized as a combination of a main part and a complementary part connected together by corridors in between. Compared with the main part, the volume of the complementary part is much smaller. Therefore, the influence on the dynamic properties of the complementary part from its counterpart is expected. To capture the dynamic properties of the coupled building, a 21-setup ambient vibration test was designed to cover all the degrees of freedom (DOFs) of interest. The modal parameters of each setup were identified following the frequency domain decomposition (FDD) method and the partial mode shapes from different setups were assembled following a least-squares method. To determine the stiffness of the linkage between the two parts, the coupled building was simulated with two linked shear buildings and updated utilizing the Markov chain Monte Carlo (MCMC)-based Bayesian model updating method. The identified modal parameters revealed interesting features about the coupled effects between the main part and complementary part and were discussed in detail. The good match between the model-predicted and identified modal parameters verified the validity of proposed shear building model. This study provides valuable experience in the area of structural model updating and structural health monitoring.

Ambient vibration test results of the Imperial County Services Building

1983 ◽  
Vol 73 (6A) ◽  
pp. 1895-1902
Author(s):  
Gerard C. Pardoen
Keyword(s):  
Strong Motion ◽  
Ambient Vibration ◽  
Vibration Test ◽  
Test Results ◽  
Structural Failure ◽  
Imperial Valley ◽  
Ambient Vibration Test ◽  
Significant Interest ◽  
First Time ◽  
County Services

Abstract The ambient vibration test results conducted on the Imperial County Services Building prior to the 15 October 1979 Imperial Valley earthquake are summarized. These results are of significant interest because the Imperial County Services Building has been the source of many postearthquake investigations due to the fact that the 1979 earthquake represented the first time a building instrumented with strong motion recorders suffered and recorded the major structural failure.

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