Structural Health Monitoring on Real Scale Model of a Masonry Triumphal Arch

Monitoring represents one solution for the safeguard of historical buildings. The need for a non-destructive and comprehensive monitoring methodology suggests using related to Structural Health Monitoring. This paper is intended to present the outcomes of an experimental campaign on a masonry triumphal arch representing a real scale model of a church part, which was built outside ELSA laboratory at the Joint Research Centre of European Commission. This study aims to evaluate the damage pattern of the structure through simplified dynamic methods producing a quick evaluation of structural safety, easy to use on real cases. As in traditional monitoring, both the instrumentation precision and the measurement variability due to the different testing condition (e.g. ambient conditions) have to be considered. The related effects on the structural dynamic behaviour were analysed and evaluated in order to distinguish an effective change in the “structural health” (a real damage) from an alteration caused by external conditions (a “false positive”). Once studied such effects, settlements were induced to one column base through an “ad hoc” device. Varying the settlement width, three damage levels were obtained in the structure. For each state the structural dynamic properties and their variation were evaluated. Sensitivity of dynamic behaviour to structural damage and to its changes was analysed comparing the results for each level.

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Experimental Research on Quick Structural Health Monitoring Technique for Bridges Using Smartphone

Advances in Materials Science and Engineering ◽

10.1155/2016/1871230 ◽

2016 ◽

Vol 2016 ◽

pp. 1-14 ◽

Cited By ~ 14

Author(s):

Xuefeng Zhao ◽

Kwang Ri ◽

Ruicong Han ◽

Yan Yu ◽

Mingchu Li ◽

...

Keyword(s):

Structural Health Monitoring ◽

Health Monitoring ◽

Extreme Event ◽

Force Measurement ◽

Low Cost ◽

Practical Significance ◽

Scale Model ◽

Structural Health ◽

Bridge Health Monitoring ◽

Monitoring Technique

In the recent years, with the development and popularization of smartphone, the utilization of smartphone in the Structural Health Monitoring (SHM) has attracted increasing attention owing to its unique feature. Since bridges are of great importance to society and economy, bridge health monitoring has very practical significance during its service life. Furthermore, rapid damage assessment of bridge after an extreme event such as earthquake is very important in the recovery work. Smartphone-based bridge health monitoring and postevent damage evaluation have advantages over the conventional monitoring techniques, such as low cost, ease of installation, and convenience. Therefore, this study investigates the implementation feasibility of the quick bridge health monitoring technique using smartphone. A novel vision-based cable force measurement method using smartphone camera is proposed, and, then, its feasibility and practicality is initially validated through cable model test. An experiment regarding multiple parameters monitoring of one bridge scale model is carried out. Parameters, such as acceleration, displacement, and angle, are monitored using smartphone. The experiment results show that there is a good agreement between the reference sensor and smartphone measurements in both time and frequency domains.

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Autocorrelation Analysis in Time and Frequency Domains for Passive Structural Diagnostics

Advances in Acoustics and Vibration ◽

10.1155/2013/204878 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8

Author(s):

Satoru Goto ◽

Yoshinori Takahashi ◽

Mikio Tohyama

Keyword(s):

Structural Health Monitoring ◽

Health Monitoring ◽

Frequency Estimation ◽

Scale Model ◽

Monitoring Methods ◽

Autocorrelation Functions ◽

Modal Frequency ◽

Structural Health ◽

Frequency Domains ◽

Time And Frequency Domains

In this paper, modal frequency estimation by using autocorrelation functions in both the time and frequency domains for structural diagnostics is discussed. With popular structural health monitoring methods for periodic inspections such as with the “hammering test,” hearing is very useful for distinguishing differences between structural conditions. Hearing detects pitch and tone, and it is known that the auditory process is related to wave periodicity calculated from autocorrelation functions. Consequently, on the basis of the hammering test, modal frequencies can be estimated by autocorrelation, the same as hearing. In this paper, modal frequencies were estimated by using autocorrelation for constant structural health monitoring under a nonstationary noise condition. First, fundamental modal frequencies were estimated by using the autocorrelation of the time domain which was inspired by pitch detection of hearing. Second, higher modal frequency compositions were also analyzed by using autocorrelation in the frequency domain as with tones discrimination. From the results by conducting scale-model experiments under unknown nonstationary noise conditions, periods of fundamental modal frequency were derived by using periods histogram of autocorrelation functions. In addition, higher modal frequency estimation under nonstationary noises was also discussed.

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Structural Vibration Monitoring Using Cumulative Spectral Analysis

Advances in Acoustics and Vibration ◽

10.1155/2013/158329 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Satoru Goto ◽

Yoshinori Takahashi ◽

Mikio Tohyama

Keyword(s):

Spectral Analysis ◽

Structural Health Monitoring ◽

Impulse Response ◽

Health Monitoring ◽

Structural Condition ◽

Vibration Monitoring ◽

Structural Vibration ◽

Scale Model ◽

Structural Health ◽

Resonance Decay

This paper describes a resonance decay estimation for structural health monitoring in the presence of nonstationary vibrations. In structural health monitoring, the structure's frequency response and resonant decay characteristics are very important for understanding how the structure changes. Cumulative spectral analysis (CSA) estimates the frequency decay by using the impulse response. However, measuring the impulse response of buildings is impractical due to the need to shake the building itself. In a previous study, we reported on system damping monitoring using cumulative harmonic analysis (CHA), which is based on CSA. The current study describes scale model experiments on estimating the hidden resonance decay under non-stationary noise conditions by using CSA for structural condition monitoring.

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