Composites Part C Open Access最新文献

{"title":"Assessment of chitosan-PVA hydrogels infused with marine collagen peptides for potential wound healing applications","authors":"","doi":"10.1016/j.jcomc.2024.100528","DOIUrl":"10.1016/j.jcomc.2024.100528","url":null,"abstract":"<div><div>Ideal wound dressings should show enhanced moisture management at the wound site, antibacterial and physical barrier, and mechanical robustness. Additionally, it should be easy to apply to the wound and be biocompatible and non-toxic. In this study, a linker-free freeze-thaw procedure was used to create an array of chitosan/PVA hydrogels blended with commercially available marine collagen peptides. Marine collagen peptides (CP) are easily available as by-products of the marine food industry and are an inexpensive and novel source of biomaterial in this field. The different weight ratios of chitosan, PVA, and CP influenced the hydrogel properties such as swelling, gel content, evaporation, and mechanical properties. Furthermore, SEM and ATR-FTIR were used to characterize the hydrogels generated under ideal conditions. After 24 h, the optimum hydrogel (chitosan:PVA:CP ratio of 1:5:1) showed a water absorption capacity of up to 900 %, a gel content of 80 %, and a 40 % evaporation rate. The physical interactions between marine collagen peptide and gel-forming components were validated by ATR-FTIR spectra, and the hydrogel kept a sufficient porous structure for potential wound dressing application. To test the mechanical integrity of the hydrogels, compression testing was carried out showing a compressive modulus of up to ∼40 kPa. The addition of marine collagen peptide in the chitosan/PVA hydrogel increased its wettability, antimicrobial capabilities, and hemostatic properties. Furthermore, the hydrogel preparation procedure is simple and does not use toxic chemicals, serving as a model for developing safe and effective hydrogel wound dressing.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536091","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":"Cure-induced residual stresses and viscoelastic effects in repaired wind turbine blades: Analytical-numerical investigation","authors":"","doi":"10.1016/j.jcomc.2024.100521","DOIUrl":"10.1016/j.jcomc.2024.100521","url":null,"abstract":"<div><div>During scarf repair of wind turbine blades, the difference in coefficients of thermal expansion and chemical shrinkage between the original part and the repair patch leads to the development of residual stresses. These residual stresses are detrimental when the repaired composite structures are subjected to operational cyclic loads and affect their post-repair lifetime. This paper uses a hybrid analytical-numerical model to evaluate the residual stresses in a scarf-repaired composite panel. A Prony series-based viscoelastic model is used to describe the material behaviour of the composite undergoing cure to replicate real-life effects more closely. Experiments on the repaired composite samples and numerical simulations on a model of the same are performed to study the post-repair mechanical behaviour. It is found that the damage initiates at the adhesive interface between the scarf patch and the base composite. The resulting debonding and damage to the base composite leads to the failure of the repaired section.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418544","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":"Bioinspired surface modification of mussel shells and their application as a biogenic filler in polypropylene composites","authors":"","doi":"10.1016/j.jcomc.2024.100520","DOIUrl":"10.1016/j.jcomc.2024.100520","url":null,"abstract":"<div><div>This study explores the potential of mussel shells (MS) as biogenic fillers in polymer composites. The chemical composition and crystal structures of MS were characterised. To improve MS filler dispersion and adhesion within a polypropylene (PP) matrix, three surface modification methods were evaluated: polydopamine (PDA) coating, maleic anhydride-grafted polypropylene (MAPP) modification, and PDA/MAPP co-modification. The PDA coating, inspired by the adhesive properties of mussel foot proteins, successfully functionalized the MS surface, as confirmed by X-ray photoelectron spectroscopy (XPS). Thermodynamic analysis, based on contact angle measurements, revealed that MAPP and PDA/MAPP modifications reduced surface energies and potential energy differences. These changes enhanced filler dispersion and interfacial bonding by increasing hydrophobicity and reducing agglomeration in the PP matrix. Consequently, PP composites with 20% PDA/MAPP-modified MS fillers exhibited a 2.9% increase in tensile strength and a 7.5% increase in flexural strength compared to neat PP. Scanning electron microscopy (SEM) also showed reduced filler-matrix debonding and fewer voids. The proposed mechanism attributes these macroscopic property enhancements to the ability of the PDA coating to facilitate chemical and hydrogen bonding between MS fillers and MAPP.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418545","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":"Structural health monitoring of scarf bonded repaired glass/epoxy laminates interleaved with carbon non-woven veil","authors":"","doi":"10.1016/j.jcomc.2024.100526","DOIUrl":"10.1016/j.jcomc.2024.100526","url":null,"abstract":"<div><div>Bonded repair patches/joints often introduce vulnerabilities in composite laminates, making them prime candidates for structural health monitoring (SHM). In this study, stepped-scarf bonded joints were manufactured using glass fibre-reinforced epoxy laminates as representative repair patches, and a novel SHM approach through the electrical resistance change method was applied. To establish an electrically conductive path within the stepped-scarf joint, non-woven carbon fibre veils with areal weights of 10 g/m² and 20 g/m² were interlaid along the stepped bondline. Two types of tensile tests were performed. In the first set of tests, the stepped-scarf joints underwent monotonic quasi-static tensile loading until the bondline was completely fractured (catastrophic failure) and the change in electrical resistance was continuously monitored. The failure stress of the joint with a 10 g/ m² carbon veil was only marginally decreased (∼2 %) in comparison with that of the joints without a carbon veil, while the failure stress of the joint with a 20 g/m² carbon non-woven veil was considerably decreased (by ∼9 %). However, the joints with 10 g/m² and 20 g/m² carbon veils exhibited a significant change in electrical resistance (∼200 % and ∼1000 %, up to full failure, respectively). Simultaneously, the change in electrical resistance was used for the detection of damage initiation and progression, supported by digital images taken during the tests. In the second set of tests, the joints were subjected to a cyclic tensile loading/unloading regime and the change in electrical resistance was monitored. A significant amount of permanent change in resistance during the unloading phases (up to 120 % in the bondline with a 20 g/m² veil) was observed, providing insights into the laminate and bondline damage evolution. In addition, thermal images obtained with the joule heating method in the cyclic tensile tests were used to confirm the damage detected with the electrical resistance change method. Moreover, the micrographs from the fracture surfaces indicated that the variations in electrical resistance change are largely caused by damage occurring within or near the carbon veils. In conclusion, the results demonstrate that the presented SHM approach, which incorporates carbon non-woven fibre veils within non-conductive laminate composites, holds promise for monitoring damage initiation and propagation in repaired composite laminates as well as adhesively bonded composite laminate joints, without adversely influencing the structural integrity of the bondline.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535482","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":"Analysis of the deformation of conical shells made by 4D Printing of composites","authors":"","doi":"10.1016/j.jcomc.2024.100522","DOIUrl":"10.1016/j.jcomc.2024.100522","url":null,"abstract":"<div><div>4D printing of composites (4DPC) is a technique that allows the manufacturing of composite structures to shape without the use of a complex-shaped mold. Instead, only a flat mold is utilized. This innovative technique has been employed to make composite leaf springs with performance comparable to metallic springs, omega stiffeners, and corrugated core for flexible wings. Recently, this technique was applied to fabricate composite conical shells. While experimental work has successfully demonstrated the transformation from flat to conical shape, the development of a numerical method to replicate this transformation is highly desirable. The availability of such method not only provides theoretical support for the experimental result, it also provides means to develop other shapes. The lay-up sequence for transforming flat to conical shapes involves curvilinear fibers. Most if not all finite elements currently available deal only with straight fibers (even though the boundaries of the element may be curved). The objective of this research is to examine the efficiency of the analysis for the deformation of composite from flat to curve made by 4DPC by special finite elements containing curved fibers. The developed finite elements were used to determine the shapes of conical shells made using multiple distinct lay-up sequences. The direction of bending in curvilinear fiber structures is significantly influenced by the orientation of the fibers. This highlights the critical role of fiber orientation and layer composition in achieving desired shapes in 4D printed composites.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535480","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":"A systematic review of stress concentration factors (SCFs) in composite reinforced circular hollow section (CHS) joints","authors":"","doi":"10.1016/j.jcomc.2024.100515","DOIUrl":"10.1016/j.jcomc.2024.100515","url":null,"abstract":"<div><div>\"Composites are an emerging choice for strengthening and repairing compromised structures due to their attractive mechanical properties, environmental durability, and ease of application. After decades of successful use as environmental coatings and for strengthening secondary load members, and with advancements in materials and application techniques, composites are increasingly being used for primary load-bearing components, such as the joints of circular hollow section (CHS) members. The structural stress approach is widely used for the fatigue analysis of CHS joints. This approach utilises stress concentration factors (SCFs) in the joint to determine hot-spot stress, which is then used in conjunction with the respective S-N curve for fatigue life estimation. Composite reinforcement of CHS joints is increasingly being investigated to enhance fatigue life. Various studies have reported a positive impact of composite reinforcement on fatigue strength, either directly or by reducing SCFs in CHS joints. However, certain aspects remain unexplored, while others are frequently revisited. The use of composites for reinforcing tubular joints is systematically reviewed following PRISMA guidelines. Twenty-four articles were selected for detailed study after applying various exclusion and inclusion criteria and removing duplicate records, with eleven, five, three, four, and one articles on T/Y, K, KT, X, and TT-joints, respectively. A critical review of these articles shaped the current understanding of the capabilities of composite reinforcement in CHS joints for enhancing fatigue life and identified areas for future research. These gaps include the investigation of composite reinforcement for joints under combined loads, the optimisation of reinforcement layup, and the development of empirical equations for determining SCFs in various joints under different load configurations.\"</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320319","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":"Optimization of functionally graded materials to make stress concentration vanish in a plate with circular hole","authors":"","doi":"10.1016/j.jcomc.2024.100512","DOIUrl":"10.1016/j.jcomc.2024.100512","url":null,"abstract":"<div><div>This paper is devoted to the minimization of the stress concentration factor in infinite plates with circular hole made of functionally graded materials and subjected to a far-field uniform uniaxial tension. Despite the vast literature on the versatility of these materials, the novelty of the results is that the material distribution is not limited to prefixed laws, as in many works available in the literature. Instead, it is assumed to be an unknown piecewise constant function, thus aiming to derive the material distribution by exploiting, at best, the inhomogeneity concept associated with functionally graded materials. After a brief review of the governing equations, the motivation, the statement and the mathematical formulation of the optimization problem are given under the hypothesis of axisymmetric material distribution. Still, the problem could not be solved analytically, therefore a direct transcription approach by the aid of finite difference method has been followed to convert it into a nonlinear programming problem, whose solution has been obtained numerically by dedicated gradient-based solvers. Numerical optimal solutions are reported in graphical forms, thoroughly discussed and validated by means of the finite element method. The developed numerical approach yields a material inhomogeneity obeying a sigmoid-like function and a uniform hoop stress along the radial direction, thus making the stress concentration factor at the rim of the circular hole vanish.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323195","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":"Fire Performance of FRCM-Confined RC Columns: Experimental Investigation and Parametric Analysis","authors":"","doi":"10.1016/j.jcomc.2024.100514","DOIUrl":"10.1016/j.jcomc.2024.100514","url":null,"abstract":"<div><p>This study presents an experimental investigation of the fire response of six columns strengthened with polyparaphenylene benzobisoxazole (PBO) FRCM system, and tested in a large-scale furnace following ASTM <span><span>E119</span><svg><path></path></svg></span> standards. The parameters investigated included the number of PBO-FRCM layers and the presence of a fireproofing insulation layer. Test results highlighted the effectiveness of PBO-FRCM in insulating the column, with the strengthened column showing a substantial 31.9% reduction in temperature readings at the concrete surface compared to its unstrengthened counterpart. Furthermore, the presence of Sikacrete 213F fireproofing system reduced temperature readings within the column's section by an average of 65%. Based on the experimental results, a parametric numerical study were developed and verified using ABAQUS software. The parameters studied included the number of PBO-FRCM layers (0, 1, and 2 layers), the presence of a 30 mm thick insulation layer, and the axial preloading taken as 40, 60, and 75% of the ultimate column's capacity. The model accurately predicted the temperature readings across the columns. Strengthening the columns with PBO-FRCM significantly increased their resistance during fire, doubling fire-resistance duration with one layer. Adding fireproof insulation led to significant increase in load resistance duration. The percentage drop in temperature after 1 hour of fire exposure was around 70% at the FRCM surface for the insulated column strengthened with one layer of FRCM. Higher preload percentages reduced both the fire-resistance duration and ductility of the columns. For the group of columns strengthened with one layer, increasing the preloading percentage to 60% and 75% resulted in decreases in the fire-resistance duration of 35% and 73%, respectively.</p></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666682024000835/pdfft?md5=e111d521408c68abdd83d3ba5f5babce&pid=1-s2.0-S2666682024000835-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272707","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":"Effect of processing conditions on the tensile properties of PLA/Jute fabric laminates: Experimental and numerical analysis","authors":"","doi":"10.1016/j.jcomc.2024.100511","DOIUrl":"10.1016/j.jcomc.2024.100511","url":null,"abstract":"<div><p>This article explores how the mechanical properties of composite polymers reinforced with jute fibers are influenced by manufacturing conditions, specifically pressure and temperature. To investigate this, a total of 45 distinct samples were created, and fabricated under nine different pressure and temperature conditions. The results demonstrate a notable linear increase in mechanical properties with incremental changes in pressure, while the impact of temperature variations remains less clearly defined. Based on these findings, a corrective factor was developed for the homogenization formula or rule of mixture that is commonly used to predict the mechanical behavior of composite polymers but does not typically consider manufacturing conditions. The newly introduced corrective factor aims to improve the accuracy of predictions and represents a significant advancement in modeling jute fiber-reinforced composite polymers. This development opens the door for more precise predictions and a better understanding of the intricate relationship between manufacturing conditions and resulting material properties.</p></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266668202400080X/pdfft?md5=a080f64df0af5c42cdc0e4fa7c679b5d&pid=1-s2.0-S266668202400080X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142172405","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":"Finite element mesh transition for local–global modeling of composite structures","authors":"","doi":"10.1016/j.jcomc.2024.100510","DOIUrl":"10.1016/j.jcomc.2024.100510","url":null,"abstract":"<div><p>This study presents an automatic mesh generation algorithm designed to address computational challenges in simulating small-scale defects within large composite structures. The algorithm seamlessly transitions from a coarse mesh, corresponding to the global structure, to a highly refined mesh in targeted local regions of interest. The transition element number and shape can be adjusted by the specified parameters. Tailored to complement this method for non-homogeneous composite models, which include multiple materials such as cohesive layers representing interlayer properties, a volume fraction calculator is integrated to automatically assign the mixture material property in each transition element. Entire processes are fully automated using a MATLAB script, eliminating the need to open the FEA software interface. The validation studies of the reconstructed two-dimensional models, assembled with the wrinkle-defect model, demonstrate their feasibility. The performance of the model is examined in terms of strain and displacement at the connecting boundaries, load–displacement curve, and interlayer failure prediction. The mesh transition model achieves agreeable results compared to a fully fine mesh model, and a 92% reduction in computational time in stress analysis, showing the efficiency of the mesh transition for local–global modeling of composite structures.</p></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666682024000793/pdfft?md5=4b3f8d2b3b71a06aba65ea854006765d&pid=1-s2.0-S2666682024000793-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142087304","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}