scholarly journals Structural health monitoring in composite materials using frequency response methods

2001 ◽  
Author(s):  
Seth S. Kessler ◽  
S. Mark Spearing ◽  
Mauro J. Atalla ◽  
Carlos E. S. Cesnik ◽  
Constantinos Soutis
Keyword(s):  
Composite Materials ◽  
Structural Health Monitoring ◽  
Frequency Response ◽  
Health Monitoring ◽  
Structural Health

Nonlinear Modeling of Cracked Beams for Impedance Based Structural Health Monitoring

2017 ◽  
Author(s):  
Naserodin Sepehry ◽  
Firooz Bakhtiari-Nejad ◽  
Mahnaz Shamshirsaz ◽  
Weidong Zhu
Keyword(s):  
Structural Health Monitoring ◽  
Linear System ◽  
Frequency Response ◽  
Frequency Domain ◽  
Health Monitoring ◽  
Impedance Method ◽  
Breathing Crack ◽  
Electromechanical Impedance ◽  
Structural Health ◽  
System Equations

One of the main objectives of the structural health monitoring by piezoelectric wafer active sensor (PWAS) using electromechanical impedance method is continuously damage detection applications. In present work impedance method of beam structure is considered and the effect of early crack using breathing crack modeling is studied. In order to model the effect of a crack in beam, the beam is connected with a rotational spring in crack location. The Rayleigh–Ritz method is used to generate ordinary differential equation of cracked beam. Firstly, only open crack is considered that this is leads to linear system equation. In linear system, time domain system equations are converted to frequency domain, and then impedance of PWAS in frequency domain is calculated. Secondly, the breathing crack is modeled to be fully open or fully closed. This phenomenon leads to the nonlinear system equations. These nonlinear equations are solved using pseudo-arc length continuation scheme and collocation method for any harmonic voltage applied to actuator. Then impedance of PWAS is calculated. Two methods are used to detect early crack using breathing crack modeling on PWAS impedance. At the first, frequency response of breathing crack in the frequency range with its sub-harmonics is calculated. Second, only frequency response of one harmonic is computed with its super-harmonics. Finally, the detection method of linear is compared with nonlinear model.

Elasto-Plastic Modeling of Beams for Impedance Based Structural Health Monitoring

2018 ◽  
Author(s):  
Naserodin Sepehry ◽  
Firooz Bakhtiari-Nejad ◽  
Weidong Zhu
Keyword(s):  
Structural Health Monitoring ◽  
Linear System ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Frequency Response ◽  
Health Monitoring ◽  
Difference Method ◽  
Impedance Method ◽  
Structural Health ◽  
System Equations

The structural health monitoring by piezoelectric wafer active sensor (PWAS) using electromechanical impedance method used for monitoring of structure. In present work impedance method of elasto-plastic beam structure is studied. In order to model the effect of a plastic in beam, the moment-curvature relationship for elasto-plastic region for loading and unloading is used. The finite difference method is used to discretize beam with piezoelectric. The piezoelectric actuator is modeled by equivalent moment. Then output current of piezoelectric sensor is calculated. Firstly, elastic modeling of beam is considered that this is leads to linear system equation. In linear system, time domain system equations are calculated and Fourier transform of current output obtained, and then impedance of PWAS in frequency domain is calculated. Secondly, the elasto-plastic of beam is modeled. This phenomenon leads to the nonlinear system equations. These nonlinear equations are solved using finite difference method for any harmonic voltage applied to actuator. Then impedance of PWAS is calculated. Two methods are used to detect elasto-plastic modeling on PWAS impedance. At the first, frequency response of elastic beam as intact model is compared with elasto-plastic results in a desired frequency range. Second, only frequency response of one harmonic is computed with its super-harmonics. Finally, the detection method of linear is compared with nonlinear model.

Use of Time-Series Predictive Models for Piezoelectric Active-Sensing in Structural Health Monitoring Applications

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Eloi Figueiredo ◽  
Gyuhae Park ◽  
Kevin M. Farinholt ◽  
Charles R. Farrar ◽  
Jung-Ryul Lee
Keyword(s):  
Time Series ◽  
Structural Health Monitoring ◽  
Frequency Response ◽  
Frequency Domain ◽  
Health Monitoring ◽  
Active Sensing ◽  
Response Functions ◽  
Active Sensors ◽  
Frequency Response Functions ◽  
Structural Health

In this paper, time domain data from piezoelectric active-sensing techniques is utilized for structural health monitoring (SHM) applications. Piezoelectric transducers have been increasingly used in SHM because of their proven advantages. Especially, their ability to provide known repeatable inputs for active-sensing approaches to SHM makes the development of SHM signal processing algorithms more efficient and less susceptible to operational and environmental variability. However, to date, most of these techniques have been based on frequency domain analysis, such as impedance-based or high-frequency response functions-based SHM techniques. Even with Lamb wave propagations, most researchers adopt frequency domain or other analysis for damage-sensitive feature extraction. Therefore, this study investigates the use of a time-series predictive model which utilizes the data obtained from piezoelectric active-sensors. In particular, time series autoregressive models with exogenous inputs are implemented in order to extract damage-sensitive features from the measurements made by piezoelectric active-sensors. The test structure considered in this study is a composite plate, where several damage conditions were artificially imposed. The performance of this approach is compared to that of analysis based on frequency response functions and its capability for SHM is demonstrated.

Composite High-Rise Structures: Structural Health Monitoring (SHM) and Case Studies

2018 ◽  
Vol 940 ◽  
pp. 146-152
Author(s):  
Koorosh Gharehbaghi ◽  
Maged Georgy ◽  
Farshid Rahmani
Keyword(s):  
Composite Materials ◽  
Structural Health Monitoring ◽  
Case Studies ◽  
Health Monitoring ◽  
Structural Integrity ◽  
Focal Point ◽  
Fiber Reinforced Concrete ◽  
Chemical Compositions ◽  
Structural Health ◽  
High Rise

High-rise construction typically implies a multi-storey structure approximately between forty to hundred and twenty meters tall (approximately twelve to forty storeys). On the other hand, composite materials are those made from two or more constituents generally with considerably dissimilar physical or chemical compositions. The focal point in this paper is in-particular on high-rise construction and whether or not composite materials’ structural integrity, and long-term sustainability, is comparable to that of a traditional building. To assess the composite materials’ structural integrity, Structural Health Monitoring (SHM) will also be utilised. While, composites possess different characteristics from those common to traditional materials; the universal purpose of producing such materials is to produce matters, which are stronger, lighter, and commonly less expensive. Generally, in construction, the composite materials typically include geo-polymers, fiber-reinforced concrete and others. For high-rise construction, these composite materials require to bear a variety of demanding conditions, including high winds and seismic conditions, which are important design factors for such structures. Nevertheless, a particular benefit of composite materials for high rise construction is their overall ability to maintain structural integrity despite their lack of conventional composition. The composite materials are traditionally utilised for high-rise buildings in order to reinforce the overall structural integrity. Accordingly, this paper will also include a number of case studies to support the ever-increasing utilization of composite materials for high-rise construction.

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