Xiaodong Liu, Kai Huang, Xiaojian Han, Jindi Zhou, Li Zhang, Licheng Guo
{"title":"Investigation of temperature and structural configuration effects on the mechanical properties of CFRP bolted joints","authors":"Xiaodong Liu, Kai Huang, Xiaojian Han, Jindi Zhou, Li Zhang, Licheng Guo","doi":"10.1016/j.compstruct.2025.119128","DOIUrl":"10.1016/j.compstruct.2025.119128","url":null,"abstract":"<div><div>Composite bolted joints are extensively employed in structural applications and have garnered notable interest in composite component design. This research examined how temperature, hole size, and washer configuration influence the composite bolted joint’s tensile properties, using 3D digital image correlation (DIC) and acoustic emission (AE) methods. The study analyzed load–displacement response, surface strain evolution, damage mode characterization, and damage initiation of joint throughout the tensile testing. The strain and displacement fields of the joint surfaces effectively revealed the competing evolution mechanisms between axial tensile effect and secondary bending effect. The k-means++ clustering algorithm and sentry function were employed to accurately identify damage modes and initiation in the joints. The results indicate that temperature, hole diameter, and washer configuration significantly influence joint strength, with the dominance of axial tensile effects and secondary bending effects varying depending on the load level. Double-sided washers delay damage initiation, while an increase in hole diameter causes damage to initiate earlier. High temperatures significantly delay the initiation of various damage modes.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"362 ","pages":"Article 119128"},"PeriodicalIF":6.3,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yirui Zhang , Chi Ren , Lingfei Qian , Yang Wei , Jie Liu , Guofen Li
{"title":"Machine learning-based capacity model for CFST columns with damaged BFRP jackets","authors":"Yirui Zhang , Chi Ren , Lingfei Qian , Yang Wei , Jie Liu , Guofen Li","doi":"10.1016/j.compstruct.2025.119120","DOIUrl":"10.1016/j.compstruct.2025.119120","url":null,"abstract":"<div><div>The use of concrete-filled steel tubular (CFST) columns reinforced with basalt fiber-reinforced polymer (BFRP) jackets is increasingly prevalent in construction engineering. However, BFRP jackets are prone to physical damage during joint design or maintenance, which can weaken their confinement effect on CFST columns. Consequently, the damage parameters of BFRP jackets are crucial for the reinforcement of CFST structures. In this study, past experimental data were validated using a finite element model (FEM). Building on this reliable FEM, a comprehensive database was created, consisting of 495 data points, encompassing various damage conditions such as direction, location, angle, and quantity. A method for normalizing different damage parameters was proposed to quantitatively describe their respective damage characteristics. With the exception of the circumferential slotting damage type, all other damage types resulted in a degradation of the strengthened stiffness. Six machine learning methods were then employed to establish the capacity model, where Random Forest (RF) and CatBoost significantly outperform linear models, with R<sup>2</sup> values exceeding 0.97. SHAP analysis reveals that the scale of vertical grooves and the regional damage coefficient are key factors influencing the prediction. The research can provide a theoretical basis for the design and maintenance of BFRP-CFST columns.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"362 ","pages":"Article 119120"},"PeriodicalIF":6.3,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chenlong Ruan , Bowen Gong , Huan Wang , Xiaoliang Lai , Baofa Cheng , Hua-Xin Peng
{"title":"An analytical approach to predicting tensile pseudo-ductility and multi-stage failure process of multidirectional thin-ply CFRP laminates","authors":"Chenlong Ruan , Bowen Gong , Huan Wang , Xiaoliang Lai , Baofa Cheng , Hua-Xin Peng","doi":"10.1016/j.compstruct.2025.119129","DOIUrl":"10.1016/j.compstruct.2025.119129","url":null,"abstract":"<div><div>This paper presents an analytical model for predicting the nonlinear tensile response and progressive failure modes of multidirectional laminates. The proposed method extends the unidirectional pseudo-ductility model to multidirectional laminates and captures the complete failure process by taking accounts of various failure modes, including fiber breakage, matrix transverse failure, free-edge delamination, and potential intermediate layer fragmentation and delamination. Combining the matrix nonlinearity with fiber fracture and delamination in the intermediate layer, the [±<em>θ<sub>n</sub></em>/0°<em><sub>m</sub></em>/±<em>θ<sub>n</sub></em>] configuration theoretically exhibits the highest uniaxial tensile pseudo-ductility, which is influenced by factors such as ply thickness, ply angle, and proportion of plies. Tensile testing on specimens with various thin-ply [±<em>θ<sub>n</sub></em>/0°<sub>2</sub>/±<em>θ<sub>n</sub></em>] configurations were conducted to validate the accuracy of the prediction model. The results showed a good agreement in the stress–strain responses. Furthermore, the [±30°<sub>6</sub>/0°<sub>2</sub>/±30°<sub>6</sub>] configuration exhibited intermediate ply fragmentation with a pseudo-ductile strain of 4.04 %, while other configurations with higher 0° ply proportions experienced catastrophic delamination or fracture. The Digital Image Correlation (DIC) results illustrated the strain evolution process, showing progressive delamination for the [±30°<sub>6</sub>/0°<sub>2</sub>/±30°<sub>6</sub>] configuration and catastrophic delamination for the [±30°<sub>4</sub>/0°<sub>2</sub>/±30°<sub>4</sub>] configuration. The analytical approach offers a straightforward method for capturing failure modes and stress–strain responses, facilitating pseudo-ductility design in multidirectional laminates.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"362 ","pages":"Article 119129"},"PeriodicalIF":6.3,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qingyuan Lin , Yong Zhao , Yuming Liu , Wei Pan , Yu Ren , Wencai Yu
{"title":"Optimization of assembly parameters for composite bolted joints aiming at time-varying bearing reliability improvement","authors":"Qingyuan Lin , Yong Zhao , Yuming Liu , Wei Pan , Yu Ren , Wencai Yu","doi":"10.1016/j.compstruct.2025.119113","DOIUrl":"10.1016/j.compstruct.2025.119113","url":null,"abstract":"<div><div>Bolted connections are a common assembly form for composite structures. Different assembly parameters may lead to multiply differences in the strength of composite bolted joints. Low structural reliability is currently a key bottleneck that restricts the performance improvement of composite devices. In this study, the uncertainty characteristics of the washer structure parameters, interface friction coefficients and tightening process parameters under different machining methods, interface treatments and tightening control methods are analyzed through batch experimental tests. Then the data set with assembly parameters as input and structural bearing limit as output is constructed through batch virtual tightening- tensile experiments. The data-driven algorithm is used to construct a fast prediction model of the bearing limit, and the time-varying uncertainty analysis of the bearing limit and the bearing reliability evaluation method are established. Finally, the method is used to realize the bearing reliability improvement by regulating the uncertainty to optimize the assembly parameters. The uncertainties in the assembly parameters of the composite bolted joints obtained through experimental tests in this study can provide a reference for related researches. The established data-driven fast prediction model of bearing limits provides an effective tool for statistical analysis of bearing limits and bearing reliability assessment.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"363 ","pages":"Article 119113"},"PeriodicalIF":6.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sharjeel Ahmed Khan , Raphaël Royer , Marta Saraiva , Nazanin Emami , Amilcar Ramalho
{"title":"In-depth tool wear analysis in drilling of CFRP-Ti stacks by DLC coated drills","authors":"Sharjeel Ahmed Khan , Raphaël Royer , Marta Saraiva , Nazanin Emami , Amilcar Ramalho","doi":"10.1016/j.compstruct.2025.119110","DOIUrl":"10.1016/j.compstruct.2025.119110","url":null,"abstract":"<div><div>Spurred by the growing trend towards sustainability and use of green material alternatives, Carbon Fiber Reinforced Polymer paired with Titanium alloys (CFRP-Ti stacks) are employed in aerospace industry for their high strength-to-weight ratio and good galvanic corrosion resistance. However, production of holes for bolt or rivet connections, imperative for components assembly depicts unmatched difficulties in their machinability due to superior mechanical characteristics and distinct nature of stack components, causing rapid tool wear and compromised hole quality. In this work, in-depth tool wear analysis of Diamond-like-Carbon (DLC) coated drills were analysed periodically to evaluate tool wear growth and associated wear mechanism while drilling of CFRP-Ti stacks. Qualitative analysis was performed after drilling set number of holes by two DLC coated drills (DLC-Ar and DLC-Bn), and results compared with uncoated solid carbide (WC) drills tested under similar dry machining conditions. The wear progress was observed by SEM and EDX; and for extensive wear mechanism investigation, Focused Ion Beam (FIB) cross-sections were analysed. Moreover, morphological examination of etched drills after drilling experiment was performed to observe active cutting regions for overall damage extent, gain insight about coating reminiscences and underlying wear mechanism. The results demonstrate that DLC-Bn drill showed best performance with reduced thrust forces and torque, reduced wear of cutting edges and no fracture/chipping of drill corner compared to DLC-Ar and WC drill. Although, DLC-Ar drill does alleviate corner chipping but suffer premature coating failure, undergoes intense tribo-chemical wear, excessive removal of carbide grains and generation of highest thrust forces compared to WC drill.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"363 ","pages":"Article 119110"},"PeriodicalIF":6.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhixuan Sun , Yu Gong , Kun Chen , Hao Liu , Jianyu Zhang , Libin Zhao , Ning Hu
{"title":"A new bionic lattice structure design and compressive mechanical properties based on the beetle elytra","authors":"Zhixuan Sun , Yu Gong , Kun Chen , Hao Liu , Jianyu Zhang , Libin Zhao , Ning Hu","doi":"10.1016/j.compstruct.2025.119117","DOIUrl":"10.1016/j.compstruct.2025.119117","url":null,"abstract":"<div><div>To meet the demand for lightweight and high-strength materials in engineering applications, this research draws inspiration from the microscopic support structure of the beetle’s elytra. A novel hourglass-shaped lattice (HSL), based on biomimetic principles, was designed by extracting and transforming the hollow strut features of the beetle’s elytra. Nylon PA2200 was chosen as the matrix material for the specimen, which was fabricated using additive manufacturing and then subjected to a quasi-static compression test. The experimental results showed that the standard HSL structure (HSL-2S) possessing two connecting rods had a maximum increase in elastic modulus by 54.89 %, yield strength by 128.99 %, and compressive strength by 218.08 % as compared to the Circle, Square, and Square-incline thin-walled structures. Additionally, this research provided an in-depth analysis of the influence of design parameters, including the number of rods and the thickness of the shell, on structural performance using the method of controlled variables. The results showed that a reasonable arrangement of rods most effectively improves the mechanical performance of the structure. The research findings offered valuable design references for the development of lattice structures with excellent mechanical properties and efficient energy absorption.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"363 ","pages":"Article 119117"},"PeriodicalIF":6.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinze Cui , Xiyan Li , Yutai Luo, Simin Zhang, Feng Bao, Jiali Yu, Huichao Liu, Caizhen Zhu, Jian Xu
{"title":"Enhanced impregnation behavior and interfacial bonding of CF/PEEK composites by regulating molecular weight of poly (aryl ether ketone) interfacial binder","authors":"Jinze Cui , Xiyan Li , Yutai Luo, Simin Zhang, Feng Bao, Jiali Yu, Huichao Liu, Caizhen Zhu, Jian Xu","doi":"10.1016/j.compstruct.2025.119107","DOIUrl":"10.1016/j.compstruct.2025.119107","url":null,"abstract":"<div><div>The primary obstacle to enhancing the mechanical performance of CF/PEEK composites is the insufficient interfacial bonding strength and poor impregnation properties. The present study addresses this issue by focusing on the development of a highly heat-resistant and easily soluble poly (aryl ether ketone) (PFEEK) interfacial binder as well as a processing technology for chopped ultra-thin CF tapes. As a result, the CF/PEEK-2 composites (<em>Mw</em>: 12000 g/mol) exhibited optimal mechanical performance with interlaminar shear strength (ILSS), tensile strength, tensile modulus, tensile toughness, flexural strength, and flexural modulus of 86.0 MPa, 772.9 MPa, 50.2 GPa, 13.5 MJ/m<sup>3</sup>, 878.5 MPa, and 47.8 GPa, respectively, which can be attributed to the excellent impregnation properties and wettability of the CF bundles and PEEK matrix. Therefore, a heat-resistant (<em>T<sub>g</sub></em> > 250°C; <em>T<sub>d5%</sub></em> > 485°C) and diffluent PFEEK binder will provide crucial guidance for further large-scale applications of high-end CF/PEEK composites.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"362 ","pages":"Article 119107"},"PeriodicalIF":6.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yunpeng Ye, Xia Zheng, Chengliang Zhou, Xingong Li
{"title":"Macro-Micro structure engineering for reed-derived biochar composites to achieve synergetic dissipation capacities towards wide-band and strong electromagnetic wave absorption","authors":"Yunpeng Ye, Xia Zheng, Chengliang Zhou, Xingong Li","doi":"10.1016/j.compstruct.2025.119116","DOIUrl":"10.1016/j.compstruct.2025.119116","url":null,"abstract":"<div><div>Achieving integration of strong electromagnetic wave (EMW) absorption and wide absorption bandwidth through a single-component carbonaceous absorber is still considered a huge challenge due to the impedance mismatch and limited loss mechanisms. Herein, a reed-derived carbon/epoxy (RC/EP) composite absorber with ultra-wide absorption bandwidth and highly strong EMW absorption was fabricated by simultaneous regulation on the micro-structure of RC and establishment of macro-gradient of RC in EP matrix. The compartmentalized structure and gradient distribution of the optimized RC in the EP matrix boosted the reflection and scattering of the EMW, contributing outstanding impedance matching and synergetic EMW dissipation. Therefore, the RC/EP composite with the thickness of 2.0 mm presented a minimum reflection loss (RL<sub>min</sub>) of −54.3 dB and an effective absorption bandwidth (EAB) of 6.12 GHz. Varying the content and distribution of RC, the EAB of the RC/EP can cover 99.7 % of the whole Ku band. In addition, the stealth performance of RC/EP absorbing materials under actual far-field conditions is confirmed using Computer Simulation Technology (CST). This work provides a new way to realize a single-component carbonaceous absorber with both broadband and strong EMW absorbing capability, which can satisfy a wide range of applications in the fields of electronics, medical protection, and architectural invisible materials.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"363 ","pages":"Article 119116"},"PeriodicalIF":6.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Complex band structures of one-dimensional fluid-saturated porous phononic crystals in microscale","authors":"Chang Su, Wei Guan, Hengshan Hu","doi":"10.1016/j.compstruct.2025.119100","DOIUrl":"10.1016/j.compstruct.2025.119100","url":null,"abstract":"<div><div>Porous materials have enormous potential for constructing miniaturized phononic crystals (PCs) for high-frequency sound isolation and noise attenuation applications owing to their unique mechanical properties. This study established a theoretical model of elastic waves in microscale PCs formed by periodic arrangements of fluid-saturated porous materials and investigated the complex band structures of obliquely incident longitudinal waves in a one-dimensional case. The proposed model added the couple-stress theory to the Biot theory to take into account the size effect caused by the solid skeleton’s internal microstructures. The results showed that in the presence of wave-type conversion, there were three types of Bloch waves in the PCs, and an anti-crossing band gap was generated between each of the two waves. The shear-wave velocity and band-gap frequency increased considerably when the size effect was considered. The characteristic length and porosity of the softer material in the composition had the same impact on the band structure, and their increases can lead to a widening in the absolute band gaps. As the thickness difference between the two constituent materials of PCs decreased, the band gaps became increasingly noticeable.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"364 ","pages":"Article 119100"},"PeriodicalIF":6.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Field-based pre-analysis and optimization for manufacturing feasibility of automated fiber placement path planning","authors":"Xingya Xiao, Weiwei Qu, Di Yang, Yinglin Ke","doi":"10.1016/j.compstruct.2025.119112","DOIUrl":"10.1016/j.compstruct.2025.119112","url":null,"abstract":"<div><div>With the advent of automated fiber placement (AFP) machines, curvilinear tow paths are more prevalent within complex laying surfaces. However, the tow-steered pattern poses a challenge to the manufacturing process, easily causing manufacturing defects such as fiber wrinkle and gap/overlap. Therefore, it is necessary to analyze and improve the laying feasibility of the designed structure. This work applies the circulation and divergence of the orthogonal vector field to conduct a pre-analysis of the manufacturing performance (path parallelism and steering radius) of the designed fiber directions represented by angle parameterization, and provides a numerical solution for triangle mesh. In addition, path breakpoints associated with triangular gaps are considered as singularities in vector field, and their distribution probability is predicted with vector circulation. The validity of key metrics has been verified through typical ply surfaces. These analytical metrics facilitates a reasonable assessment of the manufacturability of the design site prior to actual placement, reducing manufacturing challenges. Their applications are explored in guidelines selection and breakpoint editing. Finally, an efficient smoothing optimization with complex form is proposed to enhance manufacturability of the design field. The experiments show that these metrics and optimization are suitable for complex open and rotating surfaces.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"363 ","pages":"Article 119112"},"PeriodicalIF":6.3,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}