Experimental validation of a modal flexibility-based damage detection method for a cyber-physical system

2014 ◽  
Author(s):  
Rosana E. Martinez-Castro ◽  
Edward L. Eskew ◽  
Shinae Jang
Keyword(s):  
Damage Detection ◽  
Physical System ◽  
Experimental Validation ◽  
Detection Method ◽  
Cyber Physical System ◽  
Modal Flexibility

scholarly journals Mode Shape-Based Damage Detection Method (MSDI): Experimental Validation

2021 ◽  
Vol 11 (10) ◽  
pp. 4589
Author(s):  
Ivan Duvnjak ◽  
Domagoj Damjanović ◽  
Marko Bartolac ◽  
Ana Skender
Keyword(s):  
Boundary Conditions ◽  
Damage Detection ◽  
Mode Shape ◽  
Experimental Validation ◽  
Detection Method ◽  
Dynamic Properties ◽  
Damage Index ◽  
Main Principle ◽  
The Difference ◽  
Different Levels

The main principle of vibration-based damage detection in structures is to interpret the changes in dynamic properties of the structure as indicators of damage. In this study, the mode shape damage index (MSDI) method was used to identify discrete damages in plate-like structures. This damage index is based on the difference between modified modal displacements in the undamaged and damaged state of the structure. In order to assess the advantages and limitations of the proposed algorithm, we performed experimental modal analysis on a reinforced concrete (RC) plate under 10 different damage cases. The MSDI values were calculated through considering single and/or multiple damage locations, different levels of damage, and boundary conditions. The experimental results confirmed that the MSDI method can be used to detect the existence of damage, identify single and/or multiple damage locations, and estimate damage severity in the case of single discrete damage.

ADAPTIVE-SCALE DAMAGE DETECTION FOR FRAME STRUCTURES USING BEAM-TYPE WAVELET FINITE ELEMENT: EXPERIMENTAL VALIDATION

2013 ◽  
Vol 07 (03) ◽  
pp. 1350024 ◽  
Author(s):  
SONGYE ZHU ◽  
WEN-YU HE ◽  
WEI-XIN REN
Keyword(s):  
Finite Element ◽  
Damage Detection ◽  
Experimental Validation ◽  
Detection Method ◽  
Human Vision ◽  
Scale Model ◽  
Multi Scale ◽  
Wavelet Finite Element ◽  
Portal Frame ◽  
Beam Type

The superior human vision system provides ingenious insight into an ideal damage detection strategy in which structural modeling scales are not only spatially varying but also dynamically changed according to actual needs. This paper experimentally examines the efficacy of a multi-scale damage detection method based on wavelet finite element model (WFEM). The beam-type wavelet finite element in this study utilizes the second-generation cubic Hermite multi-wavelets as interpolation functions. The dynamic testing results of a one-bay steel portal frame with multiple damages are employed in the experimental validation. Through a multi-stage updating of the WFEM, the multiple damages in the steel portal frame are detected in a progressive manner: the suspected region is first identified using a low-scale structural model, and the more accurate location and severity of the damage can be identified using a multi-scale model with local refinement. As the multi-scale WFEM considerably facilitates the adaptive change of modeling scales, the proposed multi-scale damage detection method can efficiently locate and quantify damage with minimal computation effort and a limited number of updating parameters and sensors, compared with conventional finite element methods.

An Improved Damage Detection Method and its Application

2012 ◽  
Vol 184-185 ◽  
pp. 55-60
Author(s):  
Li Yuan Ma ◽  
Tian Hui Wang ◽  
Yong Jun Li ◽  
Shi Fu Xie
Keyword(s):  
Numerical Experiment ◽  
Damage Detection ◽  
Experimental Research ◽  
Lower Order ◽  
Detection Method ◽  
New Method ◽  
Modal Parameters ◽  
Modal Flexibility ◽  
Grey Relation ◽  
Multiple Scenarios

A new method called Grey Relation Modal Flexibility Curvature Difference (GRMFCD)is proposed and applied to the numerical experiment and experimental research of a substructure. The results show the ability of GMFCD to locate the inflicted damage and qualitatively evaluate its severity for single and multiple scenarios, with only a few lower order modal parameters. The effectiveness and advantages of GMFCD as compared to the flexibility indicators, such as the change in flexibility, the curvature of the flexibility difference, are demonstrated.

scholarly journals Structural Health Monitoring in Changing Operational Conditions Using Tranmissibility Measurements

2010 ◽  
Vol 17 (4-5) ◽  
pp. 651-675 ◽  
Author(s):  
Christof Devriendt ◽  
Flavio Presezniak ◽  
Gert De Sitter ◽  
Katy Vanbrabant ◽  
Tim De Troyer ◽  
...  
Keyword(s):  
Damage Detection ◽  
Experimental Validation ◽  
Detection Method ◽  
Early Stage ◽  
Specific Property ◽  
Small Frequency ◽  
Operational Conditions ◽  
Resonance Frequencies ◽  
Single Input ◽  
Simple Ratio

This article uses frequency domain transmissibility functions for detecting and locating damage in operational conditions. In recent articles numerical and experimental examples were presented and the possibility to use the transmissibility concept for damage detection seemed quite promising. In the work discussed so far, it was assumed that the operational conditions were constant, the structure was excited by a single input in a fixed location. Transmissibility functions, defined as a simple ratio between two measured responses, do depend on the amplitudes or locations of the operational forces. The current techniques fail in the case of changing operational conditions. A suitable operational damage detection method should however be able to detect damage in a very early stage even in the case of changing operational conditions. It will be demonstrated in this paper that, by using only a small frequency band around the resonance frequencies of the structure, the existing methods can still be used in a more robust way. The idea is based on the specific property that the transmissibility functions become independent of the loading condition in the system poles. A numerical and experimental validation will be given.

Implementation of a Cyber-Physical System Using Wireless Sensor Networks for Monitoring Patients

2015 ◽  
Vol 1 ◽  
pp. 26 ◽  
Author(s):  
Vo Que Son ◽  
Do Tan A
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Physical System ◽  
Patient Monitoring ◽  
High Reliability ◽  
Vital Signs ◽  
Wireless Sensor ◽  
Cyber Physical System ◽  
Self Administration ◽  
Hospital Units

Sensing, distributed computation and wireless communication are the essential building components of a Cyber-Physical System (CPS). Having many advantages such as mobility, low power, multi-hop routing, low latency, self-administration, utonomous data acquisition, and fault tolerance, Wireless Sensor Networks (WSNs) have gone beyond the scope of monitoring the environment and can be a way to support CPS. This paper presents the design, deployment, and empirical study of an eHealth system, which can remotely monitor vital signs from patients such as body temperature, blood pressure, SPO2, and heart rate. The primary contribution of this paper is the measurements of the proposed eHealth device that assesses the feasibility of WSNs for patient monitoring in hospitals in two aspects of communication and clinical sensing. Moreover, both simulation and experiment are used to investigate the performance of the design in many aspects such as networking reliability, sensing reliability, or end-to-end delay. The results show that the network achieved high reliability - nearly 97% while the sensing reliability of the vital signs can be obtained at approximately 98%. This indicates the feasibility and promise of using WSNs for continuous patient monitoring and clinical worsening detection in general hospital units.

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