scholarly journals Low Velocity Impact Localization of Variable Thickness Composite Laminates

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6103
Author(s):  
Guan Lu ◽  
Yuchen Zhou ◽  
Yiming Xu
Keyword(s):  
Variable Thickness ◽  
Composite Laminates ◽  
Composite Structures ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Localization Performance ◽  
Fbg Sensors ◽  
The Impact ◽  
Impact Localization ◽  
Thickness Correction

Variable thickness composite laminates (VTCL) are susceptible to impact during use and may result in irreparable internal damage. In order to locate the internal impact damage of complex composite structures and monitor the impact signals of VTCL at the same time, a low velocity impact (LVI) monitoring system based on an optical fiber sensing network was constructed. Fiber Bragg grating (FBG) sensors are suitable for monitoring strain characteristics. By arranging FBG sensors on the laminate, we studied the spectrum analysis and localization of the impact signal collected by a FBG demodulator at constant temperature. The prior knowledge of variable thickness composite structures is difficult to obtain, and the multi-sensor dynamic monitoring is complex and difficult to realize. In order to locate the LVI of composite structures without prior knowledge, based on empirical mode decomposition (EMD), we proposed an impact localization method with zero-mean normalized cross-correlation (ZNCC) and thickness correction. The experimental results of LVI localization verification show that the ZNCC algorithm can effectively remove the temperature cross-sensitivity and impact energy influencing factors, and the thickness correction can reduce the interference of variable thickness characteristics on localization performance . The maximum localization error is 24.41 mm and the average error is 15.67 mm, which meets engineering application requirements. The method of variable-thickness normalization significantly improves impact localization performance for VTCL.

A strain amplitude-based algorithm for impact localization on composite laminates

2011 ◽  
Vol 22 (17) ◽  
pp. 2061-2067 ◽  
Author(s):  
Cristobal Hiche ◽  
Clyde K. Coelho ◽  
Aditi Chattopadhyay
Keyword(s):  
Strain Amplitude ◽  
Composite Laminates ◽  
Composite Structures ◽  
Composite Plates ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Sensor Orientation ◽  
Fbg Sensors ◽  
The Impact ◽  
Impact Localization

Automated detection of damage due to low energy impacts in composite structures is very important for aerospace structural health monitoring applications. Low-velocity impact creates subsurface damage that can significantly reduce the stiffness of a component, yet show barely visible damage. This article proposes a novel methodology for impact localization based on the maximum strain amplitude measured by fiber Bragg grating (FBG) sensors during an impact event. The approach correlates the strain amplitude of each sensor pair to find the location of highest strain corresponding to the impact location. This approach requires minimal knowledge of the structure and fewer number of sensors as opposed to current localization methods. Both simulation and experimental data are used as proof of concept. Since FBG sensors measure strain in only one direction, the effect of sensor orientation on the performance of the algorithm is also studied. The algorithm is tested on graphite/epoxy composite plates and shows good localization results in all impact cases considered.

Effect of intra-yarn hybridisation and fibre architecture on the impact response of composite laminates: Experimental and numerical analysis

2021 ◽  
pp. 095440622110373
Author(s):  
Hussein Dalfi
Keyword(s):  
Numerical Analysis ◽  
Composite Laminates ◽  
Composite Structures ◽  
Damage Mechanics ◽  
Failure Criteria ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact ◽  
The Impact

Advanced composite laminates (i.e. glass composite laminates) are highly susceptible to low velocity impact, and the induced damage failures substantially reduced their residual mechanical properties and safe-service life during their application. Therefore, experiments and simulation efforts to predict their low-velocity impact damages and energy absorbing have significant importance in composite structures design. In this regards, experimental and finite element analysis (FEA) with aiding Abaqus software were respectively performed to investigate the influence of yarn hybridisation on the response of composite laminates under low velocity impact. The hybrid yarns, which consisted of S-glass and polypropylene yarns have been used to manufacture two types of composites; non-crimp cross-ply hybrid yarns and twill hybrid fabric composites. Additionally, for comparison, the non-crimp cross-ply and twill fabric composite laminates have been made from glass fibres only. The vacuum infusion resin process has been adopted to manufacture these composite laminates. The impact performance of composite laminates has been investigated using low-velocity impact at 15 J, 35, and 50 impact energy levels. The numerical analysis was executed using Abaqus/Explicit and Hashin failure criteria and continuum damage mechanics by using homogenous shell were adopted to simulate the intra-laminar damage in layers. Meanwhile, standard cohesive inter-laminar interfaces that inserted between composite layers with quadratic stress failure criteria have been used to model delamination failures. The numerical results regarding impact force-time, displacement–time and energy-time histories plots, as well as the damage evolution behaviour of matrix crack and fibre fracture, presented an agreement with experimental results.

On the low- and high-velocity impact behaviour of hybrid composite materials at room and extreme temperature

2021 ◽  
pp. 002199832110476
Author(s):  
Ilaria Papa ◽  
Federica Donadio ◽  
Vicente Sánchez Gálvez ◽  
Valentina Lopresto
Keyword(s):  
Hybrid Composite ◽  
High Velocity ◽  
Composite Laminates ◽  
Composite Structures ◽  
High Speed ◽  
Extreme Temperature ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

A demand raised is how to improve the survivability of aircraft and naval structures concerning low- and high-velocity impacts. Since fundamental failure is due to mainly by fracture, a fundamental understanding of both mechanisms and mechanics of the material is crucial. It is important to understand the deformation and damage mechanisms involved in the impact to improve the design of composite structures. Several approaches have been exploited to improve the impact damage resistance of composite laminates in different conditions. Among these, the development of composite laminates stacking different fibres in the same matrix results very interestingly. This paper deals to investigate on the high and low speed impact performance of hybrid composite configurations made of glass/carbon and basalt fibres. Low-velocity impact at penetration and high speed tests at different impact velocity were carried out at the room and low temperatures to evaluate the goodness of hybridization proposed and the temperature effect on the composite performances. Among the three proposals, a hybrid basalt carbon configuration was identified as the best both at low speeds and at high impact speeds for both temperatures tested.

scholarly journals Low Velocity Impact Energy Monitoring and Recognition of Composite Laminates with Variable Thickness Based on Optical Fiber Sensor Network

2021 ◽  
Vol 11 (2) ◽  
pp. 584
Author(s):  
Guan Lu ◽  
Tianyu Zhu ◽  
Yiming Xu
Keyword(s):  
Optical Fiber ◽  
Impact Energy ◽  
Variable Thickness ◽  
Composite Laminates ◽  
Optical Fiber Sensor ◽  
Low Velocity Impact ◽  
Average Error ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

At present, most of the research on low velocity impact of composite laminates focuses on load location and damage assessment. To provide further early warnings about structural impact damage, impact energy can be monitored and identified. For high strength composite laminates with variable thickness, in order to further accurately evaluate the impact energy, it is necessary to adopt more suitable dynamic load signal analysis and impact energy identification methods. Therefore, a new low velocity impact monitoring and identification method for composite plates with variable thickness is proposed. All impact sample signals collected by optical fiber sensor network are decomposed by whitening Empirical Mode Decomposition (EMD); the energy feature set is established according to the impact energy eigenvalue of sample signal; according to the first order component of signal decomposition, the thickness coefficient is determined and the energy feature set is modified to evaluate the actual impact energy. Meanwhile, combined with optical fiber sensing and signal processing technology, an impact energy monitoring system has been established, and the low velocity impact monitoring and identification experiments of composite laminates with variable thickness were carried out. The proposed energy identification method successfully identified 1–3 J impact energy with an average error of 4.82%, and the average error of large thickness area with low sensitivity was significantly reduced from 13.25% to 5.67%. The results show that the thickness coefficient correction method based on whitening EMD can evaluate the low velocity impact energy more accurately, and the thickness coefficient correction step significantly improves the recognition performance.

Experimental Investigation of Impacted and Non-Impacted Composite Laminates under Compressive Loading

2011 ◽  
Vol 284-286 ◽  
pp. 607-610
Author(s):  
Jiang Tao Ruan ◽  
Min Shen ◽  
Jing Wei Tong ◽  
Shi Bin Wang ◽  
Francesco Aymerich ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Optical Measurement ◽  
Speckle Pattern ◽  
Compressive Loading ◽  
Laminated Plates ◽  
Low Velocity Impact ◽  
Compressive Deformation ◽  
Electronic Speckle Pattern Interferometry ◽  
Low Velocity ◽  
The Impact

In this paper, the deformation measurements of impacted and non-impacted composite laminates under compressive loading are taken. [03/903]S orientated cross-ply laminated plates with impact delamination and without delamination are tested using an anti-buckling testing device in compression experiment. The delamination is induced by low-velocity impact test at the impact energy level of 3.105J. For both impacted and non-impacted specimens, the compressive deformation is measured by a carrier electronic speckle pattern interferometry (CESPI) optical measurement technique. It is found that the deformation behavior of the two specimens presents a mixed deformation mode. However, the delamination has significant effect on the compressive deformation of composite laminates.

Compressive Strength of CCF300/QY8911 Composite Laminates with LVI Damage

2012 ◽  
Vol 583 ◽  
pp. 203-206
Author(s):  
Hai Ming Hong ◽  
Ming Li ◽  
Jian Yu Zhang ◽  
Yi Ning Zhang
Keyword(s):  
Compressive Strength ◽  
Impact Energy ◽  
Composite Laminates ◽  
Inflection Point ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Area ◽  
Compressive Performance ◽  
The Impact ◽  
Dent Depth

A series of low-velocity impact tests and residual compressive strength tests after impacts on CCF300/QY8911 composite materials were carried out to study the mechanism of compression failure of the laminates after low-velocity impact. The curves of impact energy verse dent depth and impact energy verse the damage area was obtained. And the residual compressive strength and stiffness after impact verse damage parameters were analyzed. The results showed that when the impact energy exceeded the inflection point, as the impact energy increased, the dent depth on the impacted surface of the laminates notably increased while the damage area of the internal layers merely increased slowly. If the impact energy was continued to increase, the expansion of the laminates' internal damage mainly consisted of fiber breaks. The main reason for the decrease in compressive performance of composite laminates was inside delamination between layers, while in the case in which impact energy exceeded the inflection point, there were no obvious changes in delamination damage area for different energy, so the residual compressive performance kept almost stable.

scholarly journals Static Residual Tensile Strength Response of GFRP Composite Laminates Subjected to Low-Velocity Impact

2020 ◽  
Vol 10 (16) ◽  
pp. 5480
Author(s):  
Jong-Il Kim ◽  
Yong-Hak Huh ◽  
Yong-Hwan Kim
Keyword(s):  
Tensile Strength ◽  
Composite Laminates ◽  
Impact Damage ◽  
Image Correlation ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Stress Concentrations ◽  
Low Velocity ◽  
Full Field ◽  
The Impact

The dependency of the static residual tensile strength for the Glass Fiber-Reinforced Plastic (GFRP) laminates after impact on the impact energy level and indent shape is investigated. In this study, two different laminates, unidirectional, [0°2]s) and TRI (tri-axial, (±45°/0°)2]s), were prepared using the vacuum infusion method, and an impact indent on the respective laminates was created at different energy levels with pyramidal and hemispherical impactors. Impact damage patterns, such as matrix cracking, delamination, debonding and fiber breakage, could be observed on the GFRP laminates by a scanning electron microscope (SEM), and it is found that those were dependent on the impactor head shape and laminate structure. Residual in-plane tensile strength of the impacted laminates was measured and the reduction of the strength is found to be dependent upon the impact damage patterns. Furthermore, in this study, stress concentrations in the vicinity of the indents were determined from full-field stress distribution obtained by three-dimensional Digital Image Correlation (3D DIC) measurement. It was found that the stress concentration was associated with the reduction of the residual strength for the GFRP laminates.

A Study on Low Velocity Impact of Woven Glass/Phenolic Composite Laminates Considering Environmental Effects

2005 ◽  
Vol 297-300 ◽  
pp. 1303-1308 ◽  
Author(s):  
Jae Hoon Kim ◽  
Duck Hoi Kim ◽  
Hu Shik Kim ◽  
Byoung Jun Park
Keyword(s):  
Compressive Strength ◽  
Environmental Effects ◽  
Impact Loading ◽  
Composite Laminates ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Internal Damage ◽  
The Impact ◽  
Phenolic Composite

The objectives of this study are to evaluate the internal damage and compressive residual strength of composite laminate by impact loading. To investigate the environmental effects, as-received and accelerated-aged glass/phenolic laminates are used. UT C-Scan is used to determine the impact damage characteristics and CAI tests are carried out to evaluate quantitatively the reduction of compressive strength by impact loading. The damage modes of the woven glass/phenolic laminates are evaluated. In the case of the accelerated-aged laminates, as aging time increases, initial failure energy and residual compressive strength decrease.

Analysis on Low Velocity Impact Damage and Compressive Residual Strength of Composite Laminates

2014 ◽  
Vol 566 ◽  
pp. 463-467
Author(s):  
Pu Xue ◽  
H.H. Chen ◽  
W. Guo
Keyword(s):  
Experimental Data ◽  
Residual Strength ◽  
Composite Laminates ◽  
Damage Mechanics ◽  
Impact Damage ◽  
Numerical Results ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

This paper studies the impact damage under low velocity impact for composite laminates based on a nonlinear progressive damage model. Damage evolution is described by the framework of the continuum damage mechanics. The real impact damage status of composite laminates has been used to analyze the residual compressive strength instead of assumptions on damage area after impact. The validity of the methodologies has been demonstrated by comparing the numerical results with the experimental data available in literature. The delamination area has an error of 11.3%. The errors of residual strength and compressive displacement are 8.9% and 15%, which indicate that the numerical results matched well with the experimental data.

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