Composites Part C Open Access最新文献

{"title":"Static and fatigue behaviour of hybrid step-lap joints in thick primary metallic aircraft structures","authors":"Amir Ekladious ,&nbsp;John Wang ,&nbsp;Nabil Chowdhury ,&nbsp;Alan Baker ,&nbsp;Wing Kong Chiu","doi":"10.1016/j.jcomc.2025.100567","DOIUrl":"10.1016/j.jcomc.2025.100567","url":null,"abstract":"<div><div>This study investigates the static and fatigue performance of bonded, mechanically fastened, and hybrid step-lap metallic joints in primary thick aircraft structures, focusing on both baseline configurations, representing optimally assembled joints with designed inherent strength, and those assembled with predefined bondline defects to simulate practical imperfections, that can go undetected by current non-destructive inspection techniques. The results demonstrate that hybrid joints, which integrate fasteners with adhesive bonding, significantly enhance static and fatigue failure resistance compared to traditional methods. While purely bonded joints nearly restore original stiffness, they remain prone to abrupt failure, particularly in the presence of undetectable bondline defects. In contrast, the hybrid joints tested in this study extended the fatigue life of the structure to more than nine times that of mechanically fastened joints, surpassing the aircraft’s service life by over twofold. The inclusion of fasteners effectively arrested crack propagation, preventing catastrophic failure and improving overall durability. Visual inspections, strain gauges, and optical monitoring confirmed the bolts’ role in reducing Mode I opening and peeling stresses. These findings underscore the potential of hybrid joints to enhance the durability and safety of thick aircraft structures, leading to significant cost savings by reducing the frequency of repairs and downtime.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100567"},"PeriodicalIF":5.3,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474947","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 novel and rapid method of integrating sensors for SHM to thermoplastic composites through induction heating","authors":"Tasdeeq Sofi ,&nbsp;Javier A. García ,&nbsp;María R. Gude ,&nbsp;Peter Wierach","doi":"10.1016/j.jcomc.2025.100568","DOIUrl":"10.1016/j.jcomc.2025.100568","url":null,"abstract":"<div><div>A novel, rapid, and efficient method for bonding Piezoceramic transducers (PCTs) to high-performance thermoplastic composites using thermoplastic adhesive films (TPAFs) and induction heating is presented. The current state-of-the-art techniques to bond PCTs to composites using epoxy adhesives can take hours. This innovative out-of-oven or autoclave procedure drastically reduces bonding time to mere minutes, thereby significantly enhancing the process efficiency. Five different TPAFs were used to bond PCTs to carbon fiber polyether-ether-ketone (CF-PEEK) coupons. After determining the process window and analyzing the effects of power, coupling distance, and time on temperature, it was found that power has the greatest influence. A 20% increase in power can result in 50.9% increase in temperature as compared to time. Controlled heating and cooling ramps were developed based on the power-temperature correlation, and their effects were analyzed through differential scanning calorimetry tests. In the controlled case, the melting enthalpy of semi-crystalline TPAF increased by 4.2%, while the glass transition temperature of amorphous TPAF increased by 2.4% compared to non-controlled case. Following successful PCT bonding, mechanical performance was evaluated through static flexural and fatigue tests. TPAFs exhibited critical strains of 0.33%-0.71%, with some exceeding the critical strains of co-bonded or epoxy-bonded PCTs in previous studies by 0.13%. Microscopic analyses revealed the dominant failure mode at the composite-adhesive interface. During fatigue testing, three out of five TPAFs performed successfully, with the highest change in electro-mechanical susceptance spectra observed in amorphous TPAF equivalent to 1.87%. Overall, an efficient methodology is proposed, particularly beneficial for applications in structural health monitoring.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"17 ","pages":"Article 100568"},"PeriodicalIF":5.3,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685728","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":"Post-joining thermal characteristics and repair integrity of carbon fiber-reinforced thermoplastic composites during ultrasonic reconsolidation at 20 kHz","authors":"Balaji Ragupathi ,&nbsp;Lena Burger ,&nbsp;Frank Balle","doi":"10.1016/j.jcomc.2025.100565","DOIUrl":"10.1016/j.jcomc.2025.100565","url":null,"abstract":"<div><div>Ultrasonic reconsolidation offers significant potential to replace traditional adhesive bonding techniques used in the aerospace industries for bonding repair patches to damaged composite structures without resin additives. Temperature, a characteristic variable, is a key factor influencing the quality of joints in ultrasonic welding of thermoplastic composites. In this study, instead of measuring temperature during the joining process, the focus was on post-joining analysis on temperature at various hold times and holding forces. The findings revealed that an average hold time of 5 s and a holding force of 750 N produced higher-quality joints with minimal damages to fiber bundles and residual matrix. Additionally, it was recommended that repair patches should only undergo a maximum of two reconsolidation cycles. Beyond this point, the fibers and matrix begins to degrade, leading to a 35% reduction in mechanical performance after the fourth cycle.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100565"},"PeriodicalIF":5.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101274","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":"Monotonic and cyclic compressive performance of self-monitoring MWCNT/PA12 cellular composites manufactured by selective laser sintering","authors":"Muhammad Umar Azam ,&nbsp;S Kumar ,&nbsp;Andreas Schiffer","doi":"10.1016/j.jcomc.2025.100566","DOIUrl":"10.1016/j.jcomc.2025.100566","url":null,"abstract":"<div><div>Herein, we experimentally investigate the mechanical and piezoresistive properties of selectively laser-sintered cellular composites under monotonic and cyclic compressive loading. Hexagonal honeycomb structures (HHSs) with relative densities of 20 %, 30 %, and 40 % were 3D printed from a ball-milled nanocomposite powder of multi-walled carbon nanotubes (MWCNTs) and polyamide 12 (PA12) with 0.3 wt.% MWCNTs. The pure PA12 HHSs exhibited lower porosity and superior mechanical properties, including collapse strength, elastic modulus and energy absorption, particularly at higher relative densities (30 % and 40 %). Notably, the specific energy absorption for the PA12 HHSs reached 24 J g⁻¹, under out-of-plane compression at 40 % relative density. Compared to neat PA12, the MWCNT/PA12 HHSs showed a reduction in strength and modulus but demonstrated excellent energy absorption efficiency of up to 53 %. Moreover, MWCNT/PA12 HHSs exhibited exceptional strain-sensing capabilities in the elastic region with gauge factors of up to 25. Cyclic tests showed that the zero-load resistance increased significantly as damage progressed during the collapse phase, highlighting their potential for application in smart, lightweight structures with integrated strain and damage-sensing functionalities.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100566"},"PeriodicalIF":5.3,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101276","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":"Basalt-silk fiber reinforced PLA composites: Effect of graphene fillers and stacking sequence","authors":"Hasibur R. Hamim ,&nbsp;Tanzim Hasan ,&nbsp;Farhan Shahriar ,&nbsp;Sazidur Rahman Chowdhury ,&nbsp;Md.Anisur Rahman ,&nbsp;Mohammad Nasim ,&nbsp;Mohammad Ahsan Habib","doi":"10.1016/j.jcomc.2025.100564","DOIUrl":"10.1016/j.jcomc.2025.100564","url":null,"abstract":"<div><div>This study explores the development of biocompatible composites using strong basalt fibers and ductile silk fibers, and a polylactic acid (PLA) matrix. Five distinct stacking sequences were fabricated via a replicable hand layup and vacuum bagging technique, with alternating layer specimens (ALT) further enhanced by the addition of graphene nanoplatelets (GNPs) at 3, 6, and 9 wt.% of the PLA matrix. The composites were characterized for tensile, flexural, impact, and interlaminar shear strengths, damping properties, electrical conductivity, moisture absorption, and morphological features. The ALT configuration exhibited superior performance, with its multi-layered structure effectively mitigating delamination. ALT composites without GNPs achieved the highest tensile strength (136.54 MPa), tensile modulus (3.42 GPa), interlaminar shear strength (0.48 MPa), impact energy (36.84 kJ/m²), and flexural strength (18.06 MPa), predominantly failing via delamination. SEM analysis identified the basalt fiber-PLA interface as a critical failure site. The incorporation of 6 wt.% GNP enhanced damping by 1.54 times, but the composites remained nonconductive due to graphene agglomeration and lack of a conductive network. These energy-absorbing, environmentally sustainable composites show promise for multifaceted applications with reduced ecological impact.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100564"},"PeriodicalIF":5.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101212","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":"Fabrication and characterization of the flexible three-layered thin film composites based on MXene/Fe3O4/MWCNT for electromagnetic shielding applications","authors":"Mariam Mansoori,&nbsp;Shaohong Luo,&nbsp;Daniel Choi","doi":"10.1016/j.jcomc.2025.100562","DOIUrl":"10.1016/j.jcomc.2025.100562","url":null,"abstract":"<div><div>Our research demonstrates the practical implementation of using multilayer (three layers) composites for electromagnetic interference (EMI) shielding. Three layers are: (1) The composites of multi-walled carbon nanotubes (MWCNT)/ carboxymethylcellulose (CMC) as the bottom layer; (2) The composites of MWCNT/CMC/iron oxide (Fe₃O₄) particles as the middle layer; (3) The composites of MXene/MWCNT/CMC/Fe₃O₄ as the top layer. Composition of each layer was optimized in order to maximize the electromagnetic properties of each layer. Each composite layer has outstanding electrical conductivity and excellent EMI shielding performance. The multilayer exhibits an EMI SE_T of 48 dB, SE_A of more than 33 dB, and low SE_R of 15 dB in the X-band frequencies range, significantly enhanced compared to the single-layered materials for EMI applications.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100562"},"PeriodicalIF":5.3,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101275","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":"Flexural characteristics of additively manufactured continuous fiber-reinforced honeycomb sandwich structures","authors":"Rafael Guerra Silva ,&nbsp;Gustavo Morales Pavez","doi":"10.1016/j.jcomc.2025.100563","DOIUrl":"10.1016/j.jcomc.2025.100563","url":null,"abstract":"<div><div>Additive manufacturing of continuous fiber filament is an advanced process that combines continuous strands of reinforcing fibers with thermoplastic materials to create composite parts. Previous studies have explored the potential of this technology to produce solid composite materials, but its potential for the production of sandwich panels has been limited. For instance, continuous fiber can be used to reinforce the faces while lightweight customized lattice structures could be selected for the core, all built integrally in one single process. This study analyzes the effect of reinforcement material and fiber orientation on the flexural behavior of continuous fiber-reinforced sandwich structures built entirely using a commercially available fused filament fabrication printer. Three-point bending tests were carried out on sandwich panel specimens, which were built using nylon reinforced with chopped carbon fiber and two reinforcement fibers, glass or carbon fiber. The carbon fiber-reinforced sandwich panels had a higher rigidity than those reinforced with glass fiber, but carbon fiber showed significant scattering. Additionally, we explored the influence of fiber content on the flexural behavior of the composite sandwich panels. As predicted by the theoretical models, a higher fiber content led to higher values of flexural modulus and strength. The analytical models were able to predict the flexural modulus and critical load with a relative error of approximately 20 % for low fiber volume fraction in the facing. On the other hand, in carbon fiber-reinforced specimens, when doubling the fiber volume fraction in the facing, the relative error was above 60 %.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100563"},"PeriodicalIF":5.3,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101260","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":"On the thickness and layup dependence on failure mechanisms during unfolding of curved woven composites","authors":"R.D.R. Sitohang,&nbsp;S. Benou,&nbsp;L.L. Warnet,&nbsp;R. Akkerman","doi":"10.1016/j.jcomc.2025.100559","DOIUrl":"10.1016/j.jcomc.2025.100559","url":null,"abstract":"<div><div>This study investigates the failure mechanisms of curved woven Glass/Polyphenylene sulfide (G/PPS) composites and characterizes the critical strains associated with the occurrence of damages during unfolding. Tensile-bending tests were carried out to study the damage development. The damages were observed by using acoustic emission sensors, a scanning electron microscope, and a camera. The results for the (0,90) ply orientation showed that the mechanism of failure changes from intraply-dominated to interply-dominated as the laminate thickness increases. Furthermore, the change in layup for the thinnest samples, with [(0,90)]_2s, [(90,0)]_2s, and [(<span><math><mo>±</mo></math></span>45)]_2s layups, caused a change in the mode of the damage initiation, although all of them showed initiation at the fiber/matrix interfaces. Intra-yarn cracks were found at the compression side of all 4-ply samples. These cracks caused surface yarn buckling in the [(0,90)]_2s and [(<span><math><mo>±</mo></math></span>45)]_2s samples, but not in the [(90,0)]_2s.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100559"},"PeriodicalIF":5.3,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101261","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":"Safe optimization with grey-box information: Application to composites autoclave processing improvement on the fly","authors":"Mohammad Amin Roohi ,&nbsp;Milad Ramezankhani ,&nbsp;Maryam Kamgarpour ,&nbsp;Abbas S. Milani","doi":"10.1016/j.jcomc.2025.100560","DOIUrl":"10.1016/j.jcomc.2025.100560","url":null,"abstract":"<div><div>In the manufacture of aerospace-grade composites in the autoclave, the curing process plays a crucial role as it directly governs the quality of the final parts. Maintaining the part’s thermal history, namely, thermal lag and exotherm, under predetermined thresholds as well as achieving a uniform degree of cure throughout the material thickness can result in the desired product quality. Currently, for many such manufacturing applications, the optimization of the curing process (often conducted via trial-and-error) is highly expensive and time-consuming and occasionally leads to failed products. In order to address this problem, in this paper, a Safe Optimization approach is proposed. The suggested framework allows for the on-the-fly optimization of curing process configurations while avoiding interruptions typically encountered during trials. In other words, the proposed algorithm is capable of consistently yielding “pass” products as it navigates toward the optimal configuration. In particular, we introduce a hybrid optimization framework that combines a genetic algorithm, namely NSGA-II, using inexpressive stimulation (white-box) data for finding a safe initial starting point and then, the (black-box) safe logarithmic barrier method for enhancing the product quality presumably using experimental data on-the-fly. Herein, however, as proof of concept, we employ synthetic data throughout the framework in a case study.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100560"},"PeriodicalIF":5.3,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437730","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":"Investigation of the effect of extrusion process parameters and filler loading on the performance of LDPE composites reinforced with eggshell powder","authors":"Yasith S. Perera ,&nbsp;Mohammad Naaib ,&nbsp;Nisal Ariyasinghe ,&nbsp;Chamil Abeykoon","doi":"10.1016/j.jcomc.2025.100561","DOIUrl":"10.1016/j.jcomc.2025.100561","url":null,"abstract":"<div><div>Eggshells are a household waste material that contributes to landfill waste. Polymer composites reinforced with eggshell powder can be produced in large scale with melt blending using twin-screw extrusion, which can aid in reducing eggshell waste. Proper selection of extrusion parameters and filler loading is crucial in achieving composites with desired performance while optimising the extrusion process. Hence, the aim of this study is to investigate the effect of extruder parameters and filler loading on the mechanical, thermal, and rheological properties of low-density polyethylene (LDPE) composites reinforced with eggshell powder, and motor power consumption of the extruder, which should aid in optimising the melt blending process. Composites were produced with three different filler fractions (i.e., 4 wt.%, 8 wt.%, and 12 wt.%), and extruded under three different temperature settings (i.e., low: 160–200 °C, medium: 170–210 °C, and high: 180–220 °C) and three screw speed settings (i.e., 100, 150, and 200 rpm). Injection moulding was used to produce the tensile specimens for mechanical testing using the composite pellets manufactured via melt blending. The motor power consumption of the extruder rose as the screw speed increased and declined as the set temperatures of the barrel heaters increased. The results confirmed that incorporating eggshell powder as a filler led to a slight increase in the extruder's motor power consumption. Scanning electron microscopy results showed non-uniform dispersion of the filler with increasing filler content. The tensile performance of the composites was influenced by both extruder parameters and filler loading. The inclusion of the filler resulted in enhanced stiffness but compromised the ultimate tensile strength. Rheology test results exhibited a reduction in the storage and loss moduli as well as the complex viscosity due to the incorporation of eggshell powder filler. These properties were significantly influenced by the extrusion process parameters as well. However, the influence of extruder parameters and filler loading on the thermal properties of the composites was found to be negligible. This shows that the filler did not significantly disrupt or promote the nucleation and growth of crystalline regions in the LDPE matrix. It was found that, to obtain high tensile properties while retaining good rheological properties, composites with high filler contents of 8–12 wt.% should be processed at a high screw speed of 200 rpm at low set temperature conditions. Overall, the findings of this study indicate that the produced composites could be utilised for applications that require high stiffness. Furthermore, large-scale production of these composites could provide a long-term solution to the eggshell waste problem.</div></div>","PeriodicalId":34525,"journal":{"name":"Composites Part C Open Access","volume":"16 ","pages":"Article 100561"},"PeriodicalIF":5.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101211","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}