今日更新：Composite Structures 3 篇，Composites Part A: Applied Science and Manufacturing 3 篇，Composites Part B: Engineering 10 篇
Composite Structures
Numerical investigation of bond-slip behaviour between CFRP strips and concrete in shear tests under static and blast loads
Azer Maazoun, Mohamed Ben Rhouma, Stijn Matthys, David Lecompte, Ahmed Siala
doi:10.1016/j.compstruct.2024.118148
静力和爆破荷载作用下CFRP条与混凝土粘结滑移特性的数值研究
The paper is structured into two main sections. In the first part, the focus is on the finite element (FE) analysis of bond slip in a single bond shear test between concrete and carbon fiber reinforced polymer (CFRP) strips under static loads. To model the test set-up, a plastic damage material model and an elastic material model are used for the concrete prism and the unidirectional CFRP strip respectively. Three approaches, including a perfect bond model, a cohesive bond model, and contact algorithms based on recent bond slip models, are employed to simulate the bond interface. The numerical model's validity is confirmed through comparison with experimental results from the literature. The paper predicts the debonding failure mode, the strain evolution along the bond length, and the delamination loads of the CFRP strip. The cohesive bond model exhibits good agreement between numerical and experimental data. In the second part of the paper, the developed FE model is tested under blast loading and compared to the experimental results of the blast tests conducted by the authors. The experimental and numerical findings highlight a significant dynamic enhancement effect on bond-slip properties due to the propagation of the blast wave within the concrete and the high loading rate.
Auxetic mechanical metamaterials contract or expand laterally when subjected to compressive or tensile load in the axial direction and offer potential benefits in areas such as flexible electronics, aerospace, and soft actuators. Nevertheless, when metamaterials are fabricated using conventional methods, their configurations and properties are fixed, which prohibits adaptation to the specific geometric requirements of their application environment. This limits their further development. This paper proposes an auxetic mechanical metamaterial with a negative Poisson's ratio and energy absorption capability. Compression specimens are fabricated with LCD photo-curable printing technology. The deformation mechanism and in-plane compression characteristics are examined through experimental and numerical simulation methods. The influence of unit cell geometrical control parameters on Poisson's ratio and energy absorption are also explored. The results indicate the dominant deformation mechanism of metamaterial during in-plane compression is bending deformation. The negative Poisson's ratio behavior is more pronounced when compressing along the X direction than along the Y direction, and the specimens also exhibit energy absorption capacity. In addition, the metamaterials prepared by 4D printing technology can be transformed from one configuration to another under external stimuli stimulation and force, and exhibit different mechanical properties, realizing programmable and reconfigurable, further expanding their application range.
当受到轴向压缩或拉伸载荷时，辅助机械超材料会横向收缩或膨胀，在柔性电子、航空航天和软执行器等领域具有潜在的优势。然而，当使用传统方法制造超材料时，它们的结构和性质是固定的，这就禁止了对其应用环境的特定几何要求的适应。这限制了它们的进一步发展。提出了一种具有负泊松比和能量吸收能力的机械辅助超材料。采用LCD光固化印刷技术制备压缩试样。通过实验和数值模拟的方法研究了其变形机理和面内压缩特性。探讨了单元胞几何控制参数对泊松比和能量吸收的影响。结果表明，超材料在面内压缩过程中的主要变形机制是弯曲变形。沿 X 方向压缩时，负泊松比行为比沿Y方向压缩时更为明显，且试样也表现出能量吸收能力。此外，利用4D打印技术制备的超材料可以在外界刺 激和力的作用下从一种形态转变为另一种形态，并表现出不同的力学性能，实现了可编程和可重构，进一步扩大了其应用范围。
Transient heat conduction in multi-material topology optimization of thermoelastic structures involving dynamic constraints
Minh-Ngoc Nguyen, Dongkyu Lee
doi:10.1016/j.compstruct.2024.118144
涉及动力约束的热弹性结构多材料拓扑优化中的瞬态热传导
This work presents a modified solid isotropic material with penalization (SIMP) for conducting dynamic-constrained multi-material topology optimization (MMTO) of thermoelastic structures subjected to transient thermal conduction. The novelty of this study is the multi-material optimization of instantaneous temperature conduction under specific frequency constraints, which has never been studied before. The proposed method has been developed for general models of multi-material interpolations such as thermal stiffness, heat capacity, and thermal stress coefficient. The temperature environment is formulated by applying prescribed mechanical and thermal loads that are exposed over a period of time. In this work, we focus on the objective of minimizing compliance in a transient heat conduction structure while simultaneously imposing constraints on the dynamics. With high temperatures, the stiffness of the optimization results decreases while stability is still guaranteed. The sensitivity of the objective function is subsequently calculated using the discretize-then-differentiate approach for the dynamic problem as well as the adjoint variable method. This study examines the impact of thermal fields and different time increments in conjunction with dynamic criteria. The outcomes of heat conduction result in notable alterations under identical dynamic constraint levels.
Composites Part A: Applied Science and Manufacturing
Novel application of dual-nozzle 3D printer for enhanced in-situ impregnation 3D printing of dry continuous fiber reinforced composites
Kui Wang, Yangyu Huang, Ping Cheng, Yi Xiong, Antoine Le Duigou, Yong Peng, Yanni Rao, Said Ahzi
doi:10.1016/j.compositesa.2024.108231
双喷嘴3D打印机在干法连续纤维增强复合材料原位增强浸渍3D打印中的新应用
This work reported a novel two-stage in-situ impregnation method for additively manufacturing dry fiber bundles reinforced polymer composites using a commercial dual-nozzle 3D printer. This process allowed simultaneous manufacturing of both continuous fiber prepreg filaments and continuous fiber reinforced polymer composites (CFRPCs). Initially, it was demonstrated that the two-stage in-situ impregnation method significantly enhanced the printing geometrical accuracy of specimens filled with rigid continuous carbon fiber. Subsequently, the tensile performance of CFRPCs, filled with twisted continuous ramie yarns and unwound continuous carbon fiber bundles, printed using single-stage and two-stage in-situ impregnations was compared. Significantly, the two-stage in-situ impregnation method facilitated a marked improvement in the tensile strength and modulus of CFRPCs. This improvement proved the enhanced impregnation effect of fibers, validating the effectiveness of the proposed two-stage in-situ impregnation approach for dry fiber bundles reinforced composites.
A coupled data-physics computational framework for temperature, residual stress, and distortion modeling in autoclave process of composite materials
Yongjia Xu, Ze Zhao, Kalyan Shrestha, Waruna Seneviratne, Shakya Liyanage, Upul Palliyaguru, Anand Karuppiah, Jim Lua, Nam Phan, Jinhui Yan
doi:10.1016/j.compositesa.2024.108218
复合材料热压灭菌过程中温度、残余应力和变形建模的耦合数据物理计算框架
It is challenging to obtain the full-field temperature profile during autoclave processes to control the temperature uniformity and minimize the residual stress and distortion of cured composite structures. This paper proposes a coupled data-physics computational framework for full-field temperature reconstruction and the subsequent residual stress/distortion modeling by using limited monitoring temperature data. Firstly, a Long Short-Term Memory (LSTM) model is developed for full field temperature reconstruction. In this LSTM model, a cross-recombination method is proposed to maximize the value of monitored temperature data. The method effectively cuts through the bottleneck of neural network training with limited labeled data. The LSTM model’s prediction stability is enhanced based on the mean-teacher and ensemble learning strategy. To train and validate the proposed method, we perform experiments using an autoclave at the National Institute for Aviation Research (NIAR). The LSTM model’s accuracy is assessed by comparing its predicted results with the thermocouple (TC) data from measurements and high-fidelity simulation data from computational fluid dynamics (CFD). The study shows that the proposed LSTM model can effectively reconstruct the full-field temperature using limited monitoring data and significantly improve accuracy and efficiency compared with the CFD-based counterpart. Then, we create a coupled data-physics computational framework by embedding the data-driven LSTM model into a physics-based thermo-mechanical finite element model to predict residual stress and distortion. The simulation results show that the coupled data-physics framework provides an effective way for process-to-performance modeling and simulation of autoclave curing processes.
Interfacial bonding strength plays a key role in the mechanical performance of fiber reinforced polymers. However, measurement of interfacial bonding strength in fiber reinforced soft composites (FRSCs) becomes a challenging issue, because the large deformation capability of soft matrix invalidates most of current testing methods. This paper demonstrates an advanced method combining experiments and simulation, which provides a convenient and reliable means to measure both tensile strength and shear strength of interfacial bonding for FRSCs. The specimen is made by embedding a fiber bundle in a soft plate for transverse tensile test. Various stress states along the fiber–matrix interface can be realized by controlling the inclination angle of fiber bundle to the stretching direction. Tensile strength and shear strength of interfacial bonding in FRSCs can be estimated based on the analysis of critical stress states. The comparison with the widely adopted fiber pull-out test indicates that the nominal shear strength obtained in pull-out test is severely underestimated.
Fire-Retardant Anti-Microbial Robust Wood Nanocomposite Capable of Fire-Warning by Graded-Penetration Impregnation
Wenbo Che, Zehui Li, Siqi Huo, Toan Dinh, Min Hong, Cristian Maluk, Youming Yu, Yanjun Xie
doi:10.1016/j.compositesb.2024.111482
分级渗透浸渍阻燃抗微生物坚固木纳米复合材料火灾预警性能研究
Wood, renowned for its sustainability, specific strength, and thermal insulation, stands as a highly sought-after sustainable structural material. However, the inherent flammability, decay susceptibility, and inadequate mechanical strength hinder its practical applications in high-rise buildings. Here, we report a groundbreaking solution to fabricate multi-functional fire-retardant wood (M-FRW) through a coupled delignification/impregnation procedure followed by densification treatment. The GO/BA created a hybridized network on the M-FRW surface, while BA molecules penetrated the wood cell. As-created M-FRW exhibits a superior flame retardancy due to the physical barrier and catalytic charring effect of GO/BA, as reflected by an ultrahigh limiting oxygen index value of >75% and an 85% reduction in the peak of heat release rate compared to natural wood. Furthermore, the GO/BA layer of M-FRW has a sensitive fire alarm response and ultralong alarm time (∼11280 s). More impressively, M-FRW exhibits an exceptional ability to inhibit decay fungi, mold fungi, and common bacteria due to the superimposed anti-microbial effect of GO and BA. Additionally, M-FRW shows desirable mechanical and thermal insulation properties. This work provides a facile strategy to fabricate a multi-functional advanced wood nanocomposite, making them hold great potential for various engineering applications, such as intelligent buildings.
Composite material based on piezoelectric core-shell nanofibers for tactile recognition
Giacomo Selleri, Filippo Grolli, Maria Roberta Randi, Emanuele Maccaferri, Tommaso Maria Brugo, Giovanni Valdrè, Andrea Zucchelli, Davide Fabiani
doi:10.1016/j.compositesb.2024.111494
基于压电核壳纳米纤维的触觉识别复合材料
In recent years, self-sensing composite materials based on the direct piezoelectric effect have attracted widespread interest as they combine the composite material's mechanical performances with the piezoelectric phase's sensing capability. In this context, piezoelectric nanofibers exhibit minimal impact on the mechanical structure of the composite – differently from bulky films or ceramic disks - and represent a promising strategy for robotic applications or wearable devices. This work aims to develop a self-sensing laminate based on piezoelectric core-shell nanofibers (PEDOT:PSS-based core and P(VDF-TrFE)-based shell). Each layer of the laminate is made of a flexible epoxy material and embeds aligned nanofibers. By orthogonally overlapping two layers, the intersection points of the matrix-like arrangement of the nanofibers generate a network of piezoelectric pixels, which are responsible for sensing. Such a self-sensing composite material exhibited a noticeable capability to recognize the exact position of a mechanical stimulus on its surface.
Multifunctional Properties of Carbon Nanotube Yarn/Aerogel Laminate Composites
Cecil Evers, Matt Kurilich, Jin Gyu Park, Claire Jolowsky, Kaylee Thagard, Richard Liang
doi:10.1016/j.compositesb.2024.111495
碳纳米管纱/气凝胶层压复合材料的多功能性能
This work explores the multifunctional performance of scalable carbon nanotube (CNT) yarn laminate composites. Tensile, thermal, electrical, and electromagnetic interference (EMI) shielding properties are compared to state-of-the-art unidirectional IM7/5250-4 carbon fiber composite (CFRP). CNT laminates achieved a specific tensile modulus of 249.7 ± 22.3 GPa/(g/cm3), which is over double the specific modulus of the CFRP, while maintaining a specific tensile strength of 1.88 ± 0.17 GPa/(g/cm3) which is comparable to the CFRP. CNT yarn laminates demonstrated superior thermal transport properties, with in-plane thermal conductivity of 75.78 ± 14.3 W/mK, over 13 times higher than the CFRP. CNT yarn laminates were also superior in electrical conductivity, achieving a longitudinal conductivity of 5,359 ± 417 S/cm and transverse conductivity of 36.87 ± 2.55 S/cm. This translated to superior EMI shielding properties, achieving over 100 dB in the X-band, which is nearly double that of the CFRP. Incorporating CNT aerogel interwoven between CNT yarns reduced the large property variance observed in the measurements, demonstrating a multifunctional material with tensile, thermal, and electrical properties superior to the CFRP, while potentially mitigating the scalability challenges inherent to CNT nanomaterials.
Strain rate-dependent behavior of cold-sprayed additively manufactured Al-Al 2 O 3 composites: Micromechanical modeling and experimentation
Saman Sayahlatifi, Zahra Zaiemyekeh, Chenwei Shao, André McDonald, James D. Hogan
doi:10.1016/j.compositesb.2024.111479
冷喷涂增材制造al - al2o3复合材料应变速率相关行为:微观力学建模与实验
Metal matrix composites (MMCs) fabricated by cold spray additive manufacturing (CSAM) are increasingly gaining attention as structural materials due to their rapid production and scalability. Herein, the failure behavior of CSAM Al-Al 2 O 3 composites under quasi-static and dynamic compression was studied by an experimentally informed/validated 3D microstructure-based finite element (FE) model. The debonding mechanism was found to grow at a higher rate consequently dampening the particle cracking mechanism when the strain rate rises to dynamic regimes. The stress-bearing capacity of the particles plays a key role in enhancing the flow stress and elongation at failure of the CSAM composite under high strain rates due to the lower propensity of particle cracking. Eventually, the model was exercised to study the microscale failure progression in the material under elevated temperatures. For the first time in the literature, this study informs on the correlation between the microscale failure mechanisms and the mechanical performance of CSAM MMCs at the macro scale across strain rates and temperatures whose outcomes are applicable to the design of next-generation materials with a tailored performance.
A universal strategy towards the fabrication of ultra-high temperature ceramic matrix composites with outstanding mechanical properties and ablation resistance
Materials with both excellent mechanical properties and good ablation resistance are urgently needed for the applications of thermal protection system in extreme high temperature oxidizing environments. However, owing to the lack of efficient fabrication processes, the existing materials suffer from either insufficient mechanical properties or poor ablation resistance. Herein, we report a novel solid–liquid combination fabrication strategy that successfully achieves the efficient incorporation of ultra-high temperature ceramics into 3D continuous carbon fiber performs as well as rapid densification. The relative density of the green body approaches the cubic close packing of spherical particles. Using Cf/ZrB2−SiC as an example, the as-prepared composite exhibits outstanding mechanical properties with a flexural strength surpasses 600 MPa and an unprecedented work of fracture of 11851 ± 838 J/m2, which is two orders of magnitude higher than that of the currently reported bulk UHTC matrix composites. Moreover, the high ZrB2 content endows the composites with excellent ablation resistance and is thus capable of maintaining long-term non-ablative conditions at 2500 °C. The strategy possesses remarkable universality and high design flexibility, providing a time-saving and cost-effective universal strategy for the on-demand design and fabrication of high-performance ceramic, carbon, metal, and polymer matrix composites.
Rational design of SiBCN ceramics with excellent attenuation to strong electromagnetic-wave-absorbing properties at low frequency
Quan Yang, Pingan Chen, Xiangcheng Li, Yingli Zhu
doi:10.1016/j.compositesb.2024.111486
合理设计具有优良低频衰减、强电磁波吸收性能的SiBCN陶瓷
To achieve strong electromagnetic wave absorbing properties, it is important to have good impedance matching, moderate electrical conductivity, and high polarization loss, particularly at low frequency. However, meeting these requirements for polymer-derived ceramics remains challenging. This paper proposes a simple approach to addressing this challenge by adjusting the crystallinity and defects of SiBCN ceramics. The addition of Sm as a catalyst and tailored heating temperatures were used to create SiBCN ceramics with adjustable crystallinities and defective nanograins. The controlled crystallinity provided good impedance matching, while the tailored defective nanograins offered high polarization loss. The combination of these factors results in high-performance electromagnetic wave absorption, with the SiBCN ceramics achieving a minimum reflection loss of -59.13 dB at 3.6 GHz and an effective attenuation bandwidth of 6.87 GHz with a thickness of 2.22 mm. This study provides an effective strategy for the design and fabrication of strong EMW absorbing materials.
Enhanced Mechanical Performance of Bamboo Fiber/Polypropylene Composites via Micro-Nano Reinforcing Strategy
Linmin Xia, Jianyu Wu, Han Wang, Zhijian Huang, Rilong Yang, Xuexia Zhang, Fei Guo, Jiqing Li, Yan Yu
doi:10.1016/j.compositesb.2024.111488
利用微纳增强策略增强竹纤维/聚丙烯复合材料力学性能
Developing high-performance plant fiber-reinforced thermoplastic polymer composites using environmentally friendly and cost-effective methods remains a significant challenge. In this study, we present a novel micro-nano strategy for producing robust short bamboo fibers (BFs) reinforced polypropylene (PP) composites (SBFPCs) without the need for chemical modification. Our approach involves the utilization of purified short micron BFs, which is surface-coated with holocellulose nanofibers (HNFs) extracted from bamboo parenchyma cells (BP). Through conventional injection processing, the resulting SBFPCs demonstrate remarkable mechanical enhancements with just a 0.2 wt% addition of HNFs compared to control samples. Notably, the mechanical properties of our SBFPCs surpass those of most reported short plant fiber-reinforced thermoplastic composites. The superior mechanical performance of our SBFPCs can be attributed to several factors, including the use of purified micron BFs with optimal aspect ratios as the primary reinforcement phase, enhanced interfacial mechanical interlocking between BFs and the PP matrix facilitated by the addition of HNFs, and the potential dispersion of HNFs within the PP matrix at submicron or nanoscale as a secondary reinforcement phase. This study highlights the promising application of SBFPCs in engineering areas with stringent mechanical requirements.
Phosphononitrile based bismaleimide electronic packaging substrate with both fire safety and dielectric properties: assisting 5G communication
Yifan Zhou, Wenbin Ye, Wei Liu, Fukai Chu, Weizhao Hu, Lei Song, Yuan Hu
doi:10.1016/j.compositesb.2024.111489
具有防火和介电性能的膦腈基双马来酰亚胺电子封装基板:辅助5G通信
Due to the high polarizability of traditional flame retardants, it is difficult to meet the excellent dielectric properties and flame retardancy required for electronic packaging materials. Therefore, we have designed a novel linear polyphosphazene that can balance the dielectric properties and flame retardancy of bismaleimide (BMI) composites. Here, fluorinated aromatic ring structure with the large freedom volume is connected to the main chain of polydichlorophosphazene (PDCP) as a side group, resulting in multifunctional fluorinated linear polyphosphazene (PBTFP). Attributed to the excellent P/N/F combination flame retardant strategy, extremely low polarizability, and large molecular free volume, PBTFP simultaneously improves the dielectric properties and flame retardancy of the BMI composites, including UL-94 rating of V0, and a dielectric constant (Dk) as low as 2.69. In addition, as an elastomer, PBTFP exhibits positive effects on improving the hydrophobicity and toughness of BMI. Therefore, through a simple affinity substitution reaction, we prepared a multifunctional fluorinated linear polyphosphazene modified BMI based electronic packaging substrate material that can be applied to 5G high-frequency communication.
3D Printed Architectured Silicone Composites Containing a UV-Curable Rheological Modifier with Tailorable Structural Collapse
Chengzhen Geng, Zhicheng Ding, Wen Qian, Yu Su, Fengmei Yu, Yaling Zhang, Yanqiu Chen, Yu Liu, Ai Lu
doi:10.1016/j.compositesb.2024.111490
3D打印结构有机硅复合材料含有一种可紫外光固化的流变改性剂，具有可定制的结构崩溃
3D printed silicones, combining the unique physiochemical performances of silicones with the attractive design freedom of additive manufacturing, have aroused intensive interest from academia and industry owing to their attractive applications. Direct writing (DW) was the most used method to enable the 3D printing of silicones, but it was limited by its conflicting rheological requirements. Herein, we present novel design of an ultraviolet (UV)-thermal dual-cure ink for UV assisted DW of silicone composites. A UV curable rheological modifier was key to the ink design, which would not only increase the ink viscosity and yield stress substantially at low contents, but also further enhance its shape-retaining capability during printing by UV-assisted curing. As a result, challenging structures with good mechanical performances and isotropy were printable. Interestingly, the degree of structural collapse for the product could be controlled by tailoring the printing parameters, which proved to be a new design dimension for property manipulation of 3D-printed cellular architectures. Rheology of the inks and boundary conditions for structural collapse were discussed in detail. This work will open new opportunities for the development of 3D-printed silicones with customized architectures and tailored performances.
Grain structure tailoring strategy for heterogeneous lamella SiCp/2024Al composites with exceptional strength-ductility synergy
Kan Liu, Qifeng Cui, Lu Shi, Jingyu Yang, Yunpeng Cai, Yishi Su, Qiubao Ouyang, Di Zhang
doi:10.1016/j.compositesb.2024.111491
具有优异强度-塑性协同作用的非均相片状SiCp/2024Al复合材料的晶粒结构定制策略
In this work, a novel grain structure tailoring strategy using one-stepped planetary ball milling, different from conventional powder metallurgy routes that pre-prepared components with different microstructures and then mixed them up, was implemented to fabricate micro- and nano-sized SiC particles (m- & n-SiCp)/2024Al composites with heterogeneous lamella structure. The controllable transformation from homogeneous to heterogeneous grain structures is achieved via nonuniformly distributed n-SiCps induced local grain refinement. Heterogeneous lamella composites exhibit a superior modulus-strength-ductility synergy of 95.3 GPa in Young’s modulus, 750.7 MPa in tensile strength and 4.9% in uniform elongation, particularly with no less than 145% and 175% improvements in ductility and toughness, compared with homogeneous composites. Compressive stress relaxation experiments were conducted to reveal the structural dependence of plastic deformation behaviors. Sustainedly rising hetero-deformation induced (HDI) stress produced by extra geometrically necessary dislocation (GND) accumulation at heterogeneous soft/hard domain interfaces and sequential activation of multiple dislocation mediated mechanisms based on load transfer in heterogeneous lamella composites contribute to the enhanced strain hardening capacity, which offers intrinsic toughening. Also, extrinsic toughening originates from enhanced microcrack multiplication and crack-tip blunting.
