Active Monitoring for On-Line Damage Detection in Composite Structures

2003 ◽  
Vol 125 (2) ◽  
pp. 178-186 ◽  
Author(s):  
Shenfang Yuan ◽  
Wang Lei ◽  
Lihua Shi

This study focuses on an active monitoring method for damage detection applied to composite structures. Honeycomb sandwich and carbon fiber composite structures are studied. Two kinds of damage are considered: delamination and impact damage. Wavelet analysis methods are adopted to postprocess the raw monitored signal. A new damage signature is introduced to determine the presence and extent of damage in composites, while eliminating the influence of different distances between the active actuator and active monitoring elements. The proposed method is shown to be effective, reliable, and straightforward for the specimens considered in the present study, which are composed of different materials and suffer various levels of damage. An online real-time active monitoring system for damage detection is described that is based on this research.

Measurement ◽  
2021 ◽  
pp. 110336
Author(s):  
Kaleeswaran Balasubramaniam ◽  
Piotr Fiborek ◽  
Dominika Ziaja ◽  
Michał Jurek ◽  
Mirosław Sawczak ◽  
...  

2015 ◽  
Author(s):  
Gerges Dib ◽  
Ermias Koricho ◽  
Oleksii Karpenko ◽  
Mahmood Haq ◽  
Lalita Udpa ◽  
...  

2018 ◽  
Vol 18 (1) ◽  
pp. 318-333 ◽  
Author(s):  
Aggelos G Poulimenos ◽  
John S Sakellariou

Oftentimes, the complexity in manufacturing composite materials leads to corresponding structures which although they may have the same design specifications they are not identical. Thus, composite parts manufactured in the same production line present differences in their dynamics which combined with additional uncertainties due to different operating conditions may lead to the complete concealment of effects caused by small, incipient, damages making their detection highly challenging. This damage detection problem in nominally identical composite structures is pursued in this study through a novel data-based response-only methodology that is founded on the autoregressive with exogenous (ARX) excitation parametric representation of the transmittance function between vibration measurements at two different locations on the structure. This is a statistical time series methodology within which two schemes are formulated. In the first, a single-reference transmittance model representing the healthy structure is employed, while multiple transmittance models from a sample of available healthy structures are used in the second. The model residual signal constitutes for both schemes the damage detection characteristic quantity that is used in appropriate hypothesis testing procedures with the likelihood ratio test. The methodology is experimentally assessed via damage detection for a population of composite beams which are manufactured in the same production line representing the half of the tail of a twin-boom unmanned aerial vehicle. The damage detection results demonstrate the superiority of the multiple transmittance models based scheme that may effectively detect damages under significant manufacturing variability and varying boundary conditions.


Author(s):  
Karina M. Tsuruta ◽  
Leandro R. Cunha ◽  
Raquel S. L. Rade ◽  
Domingos A. Rade

The aim of this paper is to evaluate the use of the Structural Health Monitoring (SHM) technique based on the concept of electromechanical impedance for the assessment of low-energy impact damage in laminated carbon-fiber composite plates. The experiments were carried-out by using an especially designed pendulum, and were planned in such a way to accommodate a range of test conditions, such as impact energy and dimension of the impacting piece. Also, it was investigated the influence of the frequency band in which the impedance functions are measured. Additionally, statistical metamodels were built aiming at establishing functional relations between the values of the damage metric and impact energy for single and multiple impacts. The obtained results demonstrate the capability of the monitoring method to identify various damage levels corresponding to different impact conditions.


2020 ◽  
Vol 10 (2) ◽  
pp. 684 ◽  
Author(s):  
Mohamad Zaki Hassan ◽  
S. M. Sapuan ◽  
Zainudin A. Rasid ◽  
Ariff Farhan Mohd Nor ◽  
Rozzeta Dolah ◽  
...  

Banana fiber has a high potential for use in fiber composite structures due to its promise as a polymer reinforcement. However, it has poor bonding characteristics with the matrixes due to hydrophobic–hydrophilic incompatibility, inconsistency in blending weight ratio, and fiber length instability. In this study, the optimal conditions for a banana/epoxy composite as determined previously were used to fabricate a sandwich structure where carbon/Kevlar twill plies acted as the skins. The structure was evaluated based on two experimental tests: low-velocity impact and compression after impact (CAI) tests. Here, the synthetic fiber including Kevlar, carbon, and glass sandwich structures were also tested for comparison purposes. In general, the results showed a low peak load and larger damage area in the optimal banana/epoxy structures. The impact damage area, as characterized by the dye penetration, increased with increasing impact energy. The optimal banana composite and synthetic fiber systems were proven to offer a similar residual strength and normalized strength when higher impact energies were applied. Delamination and fracture behavior were dominant in the optimal banana structures subjected to CAI testing. Finally, optimization of the compounding parameters of the optimal banana fibers improved the impact and CAI properties of the structure, making them comparable to those of synthetic sandwich composites.


Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3732
Author(s):  
Jochen Moll ◽  
Matthias Schmidt ◽  
Johannes Käsgen ◽  
Jörg Mehldau ◽  
Marcel Bücker ◽  
...  

This paper presents a proof of concept for simultaneous load and structural health monitoring of a hybrid carbon fiber rudder stock sample consisting of carbon fiber composite and metallic parts in order to demonstrate smart sensors in the context of maritime systems. Therefore, a strain gauge is used to assess bending loads during quasi-static laboratory testing. In addition, six piezoelectric transducers are placed around the circumference of the tubular structure for damage detection based on the electro-mechanical impedance (EMI) method. A damage indicator has been defined that exploits the real and imaginary parts of the admittance for the detection of pin failure in the rudder stock. In particular, higher frequencies in the EMI spectrum contain valuable information about damage. Finally, the information about damage and load are merged in a cluster analysis enabling damage detection under load.


Author(s):  
Alexander H. Pesch ◽  
Ryan J. Madden ◽  
Richard E. Martin ◽  
Jerzy T. Sawicki

The technique of model-based identification is proposed to extract a model for damage in composite materials from experimental data. The proposed method is demonstrated on a unidirectional carbon fiber reinforced polymer (CFRP) beam. Impact damage is seeded in the CFRP beam using a spherical punch, causing localized damage. The specimen is evaluated through modal testing before and after the damage is seeded, with the healthy case modeled using the FEM. Finally, a virtual controller is found which eliminates error in response between the healthy model and damaged experimental system. The virtual controller, being in feedback with the healthy model at the FE node where the damage occurs, reflects the effect of the localized damage. It is found that the seeded impact damage reduces stiffness and is a source of damping inside the composite beam. Interpretation of the local damage is made through the curve fitting of the identified dynamics. To confirm the efficacy of the fit, a closed-loop is made with the healthy model which is then compared to the data from the damaged system.


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