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.

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.

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.

Dynamic characteristics of Canada's Parliament Hill towers from ambient vibrations and recorded earthquake data

2021 ◽  
Vol 48 (1) ◽  
pp. 16-25
Author(s):  
Michal Kolaj ◽  
John Adams
Keyword(s):  
Structural Damage ◽  
Nonlinear Response ◽  
Dynamic Properties ◽  
Ground Motions ◽  
Ambient Vibration ◽  
The South ◽  
Vibration Data ◽  
South West ◽  
Baseline Values ◽  
Strong Ground

The dynamic properties of Parliament Hill’s buildings (Ottawa, Canada) are of particular interest due to their important heritage value and because of the seismic retrofit project currently underway. To measure the dynamic properties directly, ambient vibration data were collected within the Peace Tower of Centre Block and the South-West Tower of East Block and processed together with weak to strong ground motions from six earthquakes. Both datasets found the fundamental mode to be 1.0–1.15 Hz for the Peace Tower and 2 Hz for the South-West Tower. The 2010 magnitude 5 Val-des-Bois earthquake induced peak accelerations of 49% g and 18% g in the top floors of the Peace and South-West towers, respectively, triggering a nonlinear response, causing the frequencies of the dominant modes to be reduced by 10%–15%. The reduction in frequency was temporary and the frequencies returned to baseline values, suggesting that there was no permanent structural damage.

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

SEISMIC ASSESSMENT OF A RETROFITTED CHIMNEY BY FEM ANALYSIS AND FIELD TESTING

2004 ◽  
Vol 04 (03) ◽  
pp. 337-359 ◽  
Author(s):  
CHERN-HWA CHEN
Keyword(s):  
System Identification ◽  
Dynamic Behavior ◽  
Fem Analysis ◽  
Field Testing ◽  
Ambient Vibration ◽  
Element Analysis ◽  
Ambient Vibration Test ◽  
Identification Approach ◽  
Central Taiwan ◽  
Analytical Approaches

The Chi-Chi Earthquake that struck Taiwan in 1999 damaged a 250 m tall chimney located in central Taiwan. To understand the dynamic behavior, failure trigger mechanism, and seismic performance of the chimney that has been rehabilitated, a study using experimental and analytical approaches was carried out. The ambient vibration test, together with a system identification approach, was used to evaluate the dynamic characteristics of the chimney. A subspace approach with an instrumental variable concept was used in the system identification. The dynamic behavior of the chimney was also simulated by a 3D finite element analysis using the commercial software SAP2000. Finally, the design code of ASCE 1975 was adopted to check the buckling capacity of the steel flues in the chimney structure. The results indicated that the calculated stresses correspond well with the actual damages observed in the steel flues.

Finite Element Model Updating of a PSC Box Girder Bridge Using Ambient Vibration Test

2010 ◽  
Vol 168-170 ◽  
pp. 2263-2270 ◽  
Author(s):  
Matthew Hiatt ◽  
Annika Mathiasson ◽  
John Okwori ◽  
Seung Seop Jin ◽  
Shen Shang ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Element Model ◽  
Ambient Vibration ◽  
Research Experience ◽  
Ambient Vibration Test ◽  
Modal Properties ◽  
Ambient Vibration Testing ◽  
Frequency Domain Decomposition

In this paper, in-field ambient vibration testing of a highway bridge in South Korea under traffic loadings has been conducted to update its finite element model for future predictive analysis and diagnosis purpose. The research results presented in this paper are outcomes from an international REU (Research Experience for Undergraduates) program in smart structures funded by US-NSF (National Science Foundation) and hosted abroad by the Korean Advanced Institute of Science and Technology (KAIST). The monitoring, modeling, and model updating of civil infrastructures are vital in maintaining new design and maintenance standards. Using the frequency domain decomposition (FDD), experimental modal properties of the structure were found and, after a finite element model was created and updated based on the modal properties. From the results, it has been concluded that (a) the FDD method successfully identified the modal characteristics of the structure from ambient vibration, (b) that model updating improved the accuracy of the finite element model, (c) Representing the structural supports as springs in the FEM improved the results from the ideally supported model.

scholarly journals Structural Health Monitoring Using Wireless Technologies: An Ambient Vibration Test on the Adolphe Bridge, Luxembourg City

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Adrien Oth ◽  
Matteo Picozzi
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Dynamic Properties ◽  
Low Cost ◽  
Vibration Characteristics ◽  
Ambient Vibration ◽  
Civil Infrastructure ◽  
Masonry Arch ◽  
Ambient Vibration Test ◽  
Structural Health

Major threats to bridges primarily consist of the aging of the structural elements, earthquake-induced shaking and standing waves generated by windstorms. The necessity of information on the state of health of structures in real-time, allowing for timely warnings in the case of damaging events, requires structural health monitoring (SHM) systems that allow the risks of these threats to be mitigated. Here we present the results of a short-duration experiment carried out with low-cost wireless instruments for monitoring the vibration characteristics and dynamic properties of a strategic civil infrastructure, the Adolphe Bridge in Luxembourg City. The Adolphe Bridge is a masonry arch construction dating from 1903 and will undergo major renovation works in the upcoming years. Our experiment shows that a network of these wireless sensing units is well suited to monitor the vibration characteristics of such a historical arch bridge and hence represents a low-cost and efficient solution for SHM.

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