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Adhesive bonding to join fiber reinforced polymer matrix composites holds great promise to replace conventional mechanical attachment techniques for joining composite components. Understanding the behavior of these adhesive joints when subjected to various environmental loads, such as lightning strike, represents an important concern in the safe de...
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... CFRP composite adherend is 101.6 mm long and bonded with 25.4 mm overlap, making the total length of the single lap joint specimen 177.8 mm (see Figs. 1 and 3). Figure 4 shows the visual observation of the lap joints after the simulated lightning strike tests at the bonded region (images show the surface of the upper CFRP composite adherend that was directly exposed to the lightning arc). From left to right are specimens 1, 2, 3 and 4, which were subjected to elevated discharge impulse currents of 71.4, ...
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The direct effects of carbon fiber-reinforced polymer (CFRP) composites with a fastener in lightning environments are very complicated. Experimental models were designed to understand the influence of different factors on the damage modes. First, different specimen structures, including unidirectional and woven fabric, were studied. Second, the dam...
Citations
... These articles explore various techniques used to study the degradation of materials and provide insights into their behavior under different conditions. Hidden Markov Models [125,189,190,107,191,151,111] [ 164,165,192,138,96,193,194,195] [ 175,196,186,177,197,104,179,198] Nonparametric This suggests that these techniques have specific applications or importance in the medical field. Table 7 shows the use of different machine learning techniques in three disciplines: material science, power engineering, and medicine. ...
Understanding degradation is crucial for ensuring the longevity and performance of materials, systems, and organisms. To illustrate the similarities across applications, this article provides a review of data-based method in materials science, engineering, and medicine. The methods analyzed in this paper include regression analysis, factor analysis, cluster analysis, Markov Chain Monte Carlo, Bayesian statistics, hidden Markov models, nonparametric Bayesian modeling of time series, supervised learning, and deep learning. The review provides an overview of degradation models, referencing books and methods, and includes detailed tables highlighting the applications and insights offered in medicine, power engineering, and material science. It also discusses the classification of methods, emphasizing statistical inference, dynamic prediction, machine learning, and hybrid modeling techniques. Overall, this review enhances understanding of degradation modelling across diverse domains.
... Furthermore, a notable degradation in tensile stiffness and bonding strength after lightning strike was observed. 18,21 Air breakdown is a common electrical phenomenon which is crucial in high-voltage research and electrical engineering. ...
... The last question is related to the relevance of simulated lightning strike tests to composite structures. A lightning strike causes local damage to various types of composite structures, such as protected CFRP composites with expanded copper mesh, unprotected CFRP composites, composites with and without paint layers [24,29,30,[68][69][70][71][72][73][74], composites with vertically interleaved fibers [74], composites containing electrically conductive nanofillers [75][76][77][78] and single-walled CNT tuball paper [79], composites with conductive coatings [80,81], metal-tufted composites [82], thermoset and thermoplastic composites [50,83], sandwiched composites [84], stitched composites [85], scarf-repaired composites [2], composites with mechanical fasteners [27], and adhesively bonded composite [86], as well as full-scale composite structures, such as wind turbine blades [18,[87][88][89]. Although existing simulated lightning strike experimental studies for CFRP composites primarily focused on unprotected and protected composites and composites with mechanical fasteners, the other composite structures are also of significant importance. ...
Lightning strike events pose significant challenges to the structural integrity and performance of composite materials, particularly in aerospace, wind turbine blade, and infrastructure applications. Through a meticulous examination of the state-of-the-art methodologies of laboratory testing and damage predictive modeling, this review elucidates the role of simulated lightning strike tests in providing inputs required for damage modeling and experimental data for model validations. In addition, this review provides a holistic understanding of what is there, what are current issues, and what is still missing in both lightning strike testing and modeling to enable a robust and high-fidelity predictive capability, and challenges and future recommendations are also presented. The insights gleaned from this review are poised to catalyze advancements in the safety, reliability, and durability of composite materials under lightning strike conditions, as well as to facilitate the development of innovative lightning damage mitigation strategies.
... In other words, what is the readiness of this technology for practical applications? To answer this question and provide future directions in using conductive fillers for lightning strike protection of various CFRP composite structures [20,21], including adhesively bonded sandwiched composites [22], in this study, we focus on experimentally evaluating the lightning strike damage tolerance of CFRP composites containing conductive nanofillers with varying weight fractions. The primary objective of the current work is to evaluate the lightning strike damage tolerance of CFRP composites containing conductive nanofillers including carbon black (CB), carbon nanotubes (CNT), and a mix of CB and CNT at varying weight fractions, and to infer, through the results of the simulated lightning strike tests, the feasibility of replacing traditional methods of lightning strike protection with lightning strike protection through direct modifying of the resin matrix by adding conductive nanofillers. ...
Conductive nanofillers, such as carbon nanotube, graphene nanoplatelets, and carbon black particles (with diameters in nanometers) have been shown to enhance the electrical conductivity of fiber reinforced polymer matrix composites in many existing studies. The motivation is primarily for lightning strike protection, electromagnetic interference shielding, de-icing, and the manufacturing of lightweight electronic components. In this paper, we evaluate the lightning strike damage tolerance of carbon fiber reinforced polymer (CFRP) matrix composite laminates containing conductive nanofillers with varying weight fractions, including carbon black (CB), carbon nanotubes (CNT), and a mix of CB and CNT, through simulated lightning strike tests, followed by both non-destructive ultrasonic inspection and destructive sectioning to characterize the damage inflicted by the simulated lightning strike. Three-point flexural tests are performed to evaluate the residual strength retained by all CFRP specimens. Results show that lightning strike damage experienced varying levels of reduction for CFRP composite specimens containing conductive fillers in comparison to the baseline specimen without fillers. Notably, the delamination only penetrated to the interface between the 1st and 2nd layer for the specimen with 0.25 wt.% CNT in comparison to the baseline CFRP specimen for which the delamination penetrated to the interface between the 5th and 6th layer. Moreover, the retention of the flexural modulus increased from 26.5% to a maximum of 95.0% for the specimen with 0.25 wt.% hybrid CB and CNT. Yet, we show that using our chosen conductive fillers cannot fully eliminate lightning strike damage. Additionally, adding conductive fillers could compromise the flexural properties. We provide discussions on future recommendations on using conductive fillers for the lightning strike protection of CFRP composites.
