Composites Part C Open Access最新文献

{"title":"Elastostatic analysis of tapered FGM beams with spatially varying material properties","authors":"Justín Murín ,&nbsp;Stephan Kugler ,&nbsp;Juraj Paulech ,&nbsp;Juraj Hrabovský ,&nbsp;Vladimír Kutiš ,&nbsp;Herbert Mang ,&nbsp;Mehdi Aminbaghai","doi":"10.1016/j.jcomc.2025.100592","DOIUrl":"10.1016/j.jcomc.2025.100592","url":null,"abstract":"<div><div>In this article an effective method for elastostatic analysis of tapered beams made of functionally-graded material (FGM) is presented. The spatially variable stiffness of the beam is the consequence of the continuous longitudinal variability of the cross-sectional dimension, accompanied by the variability of the material properties in three orthogonal directions. The longitudinally varying effective stiffnesses of the homogenized FGM beam for tension-compression, biaxial Timoshenko bending, and uniform torsion are determined, using the Reference Beam Method (RBM). For computation of primary quantities, such as internal forces and moments as well as displacements and angles of cross-sectional rotation, a novel tapered FGM finite beam element is developed. The evaluation of the normal and shear stresses in the cross-sections of the FGM beam requires relationships that consider the variability of the material properties and of the cross-sectional parameters. FGM beams of variable stiffness can be modeled efficiently, using only one finite element. The mathematical models are applied to the elastostatic analysis of cantilever beams with longitudinally variable, quadratic cross-sections, considering the aforementioned variability of the material properties. The proposed algorithm is verified by means of three-dimensional continuum mechanics and, alternatively, by very fine discretizations with solid finite elements. The accuracy of the presented method is excellent, and the computational effort is very small compared to other approaches.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100592"},"PeriodicalIF":5.3,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of application of coconut coir fiber-based wood-based panels: A literature review","authors":"Nugroho Mamayu Hayuning Bawono ,&nbsp;Baju Bawono ,&nbsp;Paulus Wisnu Anggoro ,&nbsp;Jamari Jamari","doi":"10.1016/j.jcomc.2025.100588","DOIUrl":"10.1016/j.jcomc.2025.100588","url":null,"abstract":"<div><div>Wood-based panels (WBPs) like medium-density fiberboard (MDF) rely heavily on wood resources, contributing to deforestation and sustainability challenges. Coconut coir fiber, an abundant agricultural byproduct, offers a promising alternative due to its high lignin content, mechanical strength, and environmental benefits. However, its commercial adoption in WBPs remains limited by insufficient research on bio-based adhesives and optimized processing methods. This review synthesizes current knowledge on coir fiber's properties, pre-treatment techniques (alkali, silane, enzyme), and adhesive systems (urea-formaldehyde, tannin, lignin) for WBPs. Coir's mechanical performance (tensile strength: 13.51 MPa) and density (0.63 g/cm³) are comparable to wood, but its high water absorption (90.79 % in 2H) necessitates targeted treatments. While formaldehyde-based adhesives dominate the industry, bio-alternatives like tannin and lignin show potential but require functionalization to match synthetic adhesives’ strength and durability. Critical gaps include the lack of standardized production protocols and scalable bio-adhesive formulations. Future research should prioritize hybrid adhesive development, coir-wood composite optimization, and product differentiation compare to regular WBPs. This review highlights coir's viability as a wood substitute while underscoring the need for interdisciplinary innovation to overcome technical and economic barriers.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100588"},"PeriodicalIF":5.3,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emission risks in processing and conversion of lignocellulose-based biocomposites","authors":"Nanci Ehman ,&nbsp;Sandra Rodríguez Fabià ,&nbsp;Julia Catalán ,&nbsp;Gary Chinga-Carrasco","doi":"10.1016/j.jcomc.2025.100595","DOIUrl":"10.1016/j.jcomc.2025.100595","url":null,"abstract":"<div><div>Wood-derived components (e.g. fibers, lignin, nanofibers) are widely studied to develop thermoplastic biocomposites with, for example, improved mechanical properties and reduced global warming potential. Manufacturing of biocomposite products includes compounding and conversion processes (e.g., extrusion, injection molding, and 3D printing). These processes apply mechanical forces and heat to melt thermoplastic polymers and form a given product. However, in some cases, compounding and conversion stages may generate emissions of volatile organic compounds (VOC) and/or ultrafine particles (UFP) and we must consider their effects on human health. Additionally, due to the nano-dimensions cellulose nanofibers are considered UFP. Therefore, its impacts on human health should be evaluated, especially when dried for biocomposite production. This review provides an overview of emissions generated in the production line of lignocellulose-based biocomposites, considering: wood preprocessing, extrusion, 3D printing, and injection moulding. Emissions of VOCs and UFP were considered, including the occupational exposure limits according to the current regulations and the potential health effects associated with such emissions</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100595"},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repairing high-strength concrete two-way solid slabs exposed to elevated temperature using NSM-CFRP ropes","authors":"Ahmed Ashteyat ,&nbsp;Mousa Shhabat ,&nbsp;Ibrahim Al-Hazmi","doi":"10.1016/j.jcomc.2025.100590","DOIUrl":"10.1016/j.jcomc.2025.100590","url":null,"abstract":"<div><div>Exposure of reinforced concrete (RC) structures to elevated temperatures results in significant degradation of their mechanical properties and overall structural integrity, necessitating the development of effective repair strategies to restore their load-bearing capacity and long-term durability. This study introduces a novel approach through both experimental and theoretical investigations into the efficacy of using Near-Surface Mounted (NSM) Carbon Fiber Reinforced Polymer (CFRP) ropes to repair two-way high-strength concrete (HSC) solid slabs subjected to elevated temperatures of 600 °C for a duration of 3 h. A total of eight slabs, each measuring 1050 × 1050 × 70 mm, were tested, comprising two normal-strength concrete (NSC) slabs and six HSC slabs. The study examined three primary variables: the number of CFRP ropes (2 or 3), their orientation angles (0° or 45°), and their configuration patterns (radial star or concentric squares). The key performance indicators evaluated included load capacity, failure modes, stiffness, and ductility. The experimental results indicated that the NSM-CFRP rope repairing technique significantly enhanced the structural performance of heat-damaged slabs. Load capacity improved by 12 % to 35 %, stiffness by 260 % to 343 %, and ductility by 127 % to 324 % when compared to unstrengthened slabs. Notably, the configurations of one rope in a radial star pattern around the column (R-SR) and three ropes arranged in concentric squares at a 45° angle (3R-CS 45°) demonstrated the highest recovery efficiencies, restoring the pre-fire load capacity by 10 % and 1 %, respectively. Theoretical analysis revealed that the models by El-Gamal et al. and Ospina et al. provided close alignment with the experimental findings, with average experimental-to-theoretical ratios of 1.09 and 1.12, respectively. In contrast, the ACI 440.2R-22 model was more conservative, yielding a ratio of 1.22, while the JSCE-97 model significantly overestimated the punching shear capacity, exhibiting the least accuracy among the models analyzed, with a mean ratio of 1.81 and a standard deviation of 0.126. The findings of this research underscore the viability of NSM-CFRP ropes as an efficient and economical method for restoring heat-damaged concrete slabs. This approach provides a flexible repair solution that requires minimal disruption, positioning it as an ideal option for industrial and infrastructure rehabilitation projects.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100590"},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Additive manufacturing of continuous regenerated cellulose fiber reinforced polylactic acid composites using in-situ impregnation material extrusion technique","authors":"Nishant Jain ,&nbsp;Mathias Czasny ,&nbsp;Till Butzmann ,&nbsp;Delf Kober ,&nbsp;David Karl ,&nbsp;David Schmiedjell ,&nbsp;Sabine Hild ,&nbsp;Aleksander Gurlo","doi":"10.1016/j.jcomc.2025.100594","DOIUrl":"10.1016/j.jcomc.2025.100594","url":null,"abstract":"<div><div>This study explores an innovative approach to additively manufacture 100 % bio-derived, biodegradable polylactic acid (PLA) reinforced with continuous regenerated cellulose fibres (RCFs) using an <em>in-situ</em> infiltration material extrusion technique. The impact of fiber crystallinity, surface properties, cross-sectional geometry and PLA's thermal and rheological behaviour is analysed. Single fiber pull-out test (SFPT) is utilised to evaluate fibre-matrix interactions, while tensile and flexural properties are assessed in conjunction with void analysis via optical and AFM micrographs. The results show that Biomid fibres, which exhibit ∼65 % crystallinity, demonstrate ∼31 % higher apparent interfacial shear strength (IFSS) compared to Cordenka fibres, which exhibit ∼42 % crystallinity. Furthermore, Biomid-PLA composites show a substantial increase in tensile strength, reaching ∼290 % higher and tensile modulus reaching ∼470 % higher than unreinforced PLA. In addition, the flexural strength and modulus of the Biomid-PLA composite increased by ∼71 % and ∼120 %, compared to unreinforced PLA.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100594"},"PeriodicalIF":5.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of monolithic composite laminate and stiffened structures in aeronautic applications","authors":"Bruno Castanie,&nbsp;Wiyao Azoti,&nbsp;Laurent Crouzeix,&nbsp;Ajiboye Bello,&nbsp;Rana Piega Taborda,&nbsp;Arslan Mahmood,&nbsp;Anthony Viste","doi":"10.1016/j.jcomc.2025.100585","DOIUrl":"10.1016/j.jcomc.2025.100585","url":null,"abstract":"<div><div>This paper analyses laminated stiffened composite structures in aeronautic applications, covering many key subjects. Since the certification of these structures is based on the test pyramid methodology, several aspects will be addressed, mainly: static sizing and the obtention of allowable values, damage tolerance, post-buckling, large cuts and structural testing. Secondly, the main problems associated with the manufacturing of aeronautical composite structures will be discussed. Finally, a historical presentation of the main milestones in the introduction of fibrous materials will be given, based on the successive appearance of boron, glass and carbon fibres, with the help of a selection of examples. A detailed chronology of the pioneering introduction of carbon fibres into civil aeronautics by European industry will also be provided. Recent researches, trends and innovations will be discussed. Finally, conclusions and perspectives on this wide subject will be proposed.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100585"},"PeriodicalIF":5.3,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing structural certification challenges with FEM analysis in electric seaplane CFRP wing","authors":"Jonathan Tapullima,&nbsp;Bjørn Haugen","doi":"10.1016/j.jcomc.2025.100584","DOIUrl":"10.1016/j.jcomc.2025.100584","url":null,"abstract":"<div><div>This study explores the structural certification challenges and business objectives for an electric seaplane in the general aviation category, emphasizing the verification of the composite structure under EASA CS-23. Sandwich structures and bonded joints offer significant weight reduction and structural efficiency advantages, crucial for electric aircraft. However, a fatigue damage and tolerance evaluation under CS-23 Level 4 increase these challenges, requiring exhaustive testing, analysis, and documentation to meet stringent regulatory standards. Certification complexities are further intensified by the differences in passenger capacity constraints between Level 3 and Level 4 aircraft, suggesting pursuing Level 3 certification and impacting on the business case of the emerging sustainable aviation. To evaluate the impact on the weight penalties, this study conducts a comprehensive FEM validation and comparison of two different CFRP wing structural analyses: one to comply with Level 3 certification using a monocoque sandwich structure with a bonded assembly, and the other to comply with Level 4 certification using semi-monocoque with a mechanically fastened assembly. The use of different strain allowable values for both levels defined the current strain constraints range for the composite wings, where the monocoque structure analysis showed a mass reduction of up to 19 % on average.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100584"},"PeriodicalIF":5.3,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origami-inspired self-sensing foldable composite structures: Experiments and modeling","authors":"Israr Ud Din ,&nbsp;Adnan Ahmed ,&nbsp;Kamran A. Khan","doi":"10.1016/j.jcomc.2025.100583","DOIUrl":"10.1016/j.jcomc.2025.100583","url":null,"abstract":"<div><div>Origami-inspired self-sensing foldable structures made from fiber-reinforced polymer composites (FRPCs) can be created using piezoresistive fabric laminates. These foldable structures enable real-time monitoring of the state of folds throughout the folding and unfolding processes. This study develops a simplified finite element (FE) modeling framework to predict the piezoresistive-mechanical response of the origami-inspired foldable structures. The model, implemented via UMATHT in ABAQUS®, leverages the analogy between electrical conduction and steady-state heat conduction. The piezoresistive-mechanical response of a simple folding hinge was predicted using the model and compared with the electromechanical folding experimental results. For this purpose, the hinge was manufactured by embedding rGO-coated fabric as a substrate for prepreg patches, which were consolidated using hot compression molding with varying sizes of the folding regions (3, 6, 9, and 12 mm). The folding tests revealed that the moment (M) and curvature (k) during bending depend on the fold region size (b), which in turn affects piezoresistivity, quantified as the fractional change in resistance (FCR). An inverse relationship was observed between moment, curvature, and piezoresistivity as the fold region size varied. Finally, the model was applied to predict piezoresistivity in two structures: a waterbomb base structure and an auxetic structure. We concluded that this modeling framework can be effectively used to predict the electromechanical response of full-scale foldable structures, calibrated with the experimental results of a simple folding hinge with a specific folding size.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100583"},"PeriodicalIF":5.3,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large-area high thermal conductivity graphite-carboxymethylcellulose film easily produced by mechanical exfoliation of natural graphite using a three-roll mill","authors":"Junhao Wang ,&nbsp;Hongsheng Lin ,&nbsp;Jonathon D. Tanks ,&nbsp;Yoshihiko Arao","doi":"10.1016/j.jcomc.2025.100580","DOIUrl":"10.1016/j.jcomc.2025.100580","url":null,"abstract":"<div><div>With the rapid development of the electronics industry, the demand for superior heat dissipation materials is increasing. Although many studies have been conducted on graphene films with high thermal conductivity, most of them are processed at high temperatures (∼3000 °C) using graphene oxide, which is environmentally harmful and consumes large amounts of energy. This paper reports a simple, low-cost, low-energy, high-efficiency method for the preparation of graphite films using only environmentally friendly materials. Composite films with a thermal conductivity of 298.5 Wm^-1K^-1 were successfully produced by simply dispersing and exfoliating natural graphite and carboxymethylcellulose in a roll mill and depositing by blade coating. Conventional films fabricated using graphene nanoplates (GNP) exhibited a thermal conductivity of 94.6 Wm^-1K^-1, which is significantly lower than the graphite film produced by roll-milling. Experimental and theoretical investigations reveal the reason for this is that the mixed structure of large graphite and small graphite/GNP reduces the interfacial thermal resistance while forming a denser network of heat conduction paths.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100580"},"PeriodicalIF":5.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of internal pressure control during manufacturing on residual stresses and safety performance of type 4 pressure vessels","authors":"Bartosz Popiela ,&nbsp;Stephan Günzel ,&nbsp;Marcus Schukar ,&nbsp;Georg W. Mair ,&nbsp;Katerina Krebber ,&nbsp;Holger Seidlitz","doi":"10.1016/j.jcomc.2025.100581","DOIUrl":"10.1016/j.jcomc.2025.100581","url":null,"abstract":"<div><div>Composite pressure vessels are commonly manufactured using the wet filament winding process, where various process parameters can influence the performance of the finished component. In this study two designs of wet filament wound 6.8-liter type 4 composite pressure vessels were manufactured. Both differ only by the internal pressure used during the filament winding, which primarily influences the residual stress state in the composite structure. An extensive experimental study was carried out, including 10 slow burst tests and strain measurements with fiber optic sensors. Significant differences can be observed in the performance of the two designs even though the used stacking sequence, materials and other manufacturing parameters are the same for both designs. A discussion of the differences in the behavior of both cylinder types is provided, including the strain distribution in slow burst tests and failure mechanism.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100581"},"PeriodicalIF":5.3,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}