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【新文速递】2024年1月16日复合材料SCI期刊最新文章

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今日更新:Composite Structures 3 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇

Composite Structures

Dynamic compression-shear ignition mechanism of Al/PTFE reactive materials

Hengheng Geng, Rui Liu, Yeping Ren, Pengwan Chen, Chao Ge, Haifu Wang

doi:10.1016/j.compstruct.2024.117908

Al/PTFE反应材料的动态压缩-剪切点火机理

Ignition of Al/PTFE reactive materials can occur under dynamic loading. The ignition mechanism involves a mechanical-thermal-chemical coupled process, which draws the attention of scientists and engineers. However, it is difficult to understand the mechanism, especially under complex loadings. In this paper, three different shapes of Al/PTFE sample, 0° cylinder, 30° oblique cylinder and 45° oblique cylinder, were designed. The dynamic ignition tests were carried out by Split Hopkinson Pressure Bar (SHPB). The deformation, damage and fracture process were analyzed. The mechanical response depended on the shape of the sample, which determined the dynamic compression-shear states, further it induced different ignition behavior. The energy absorption rate ignition criterion was proposed to take the place of the traditional strain rate ignition criterion. The new criterion could match the testing well. In addition, numerical simulation on SHPB was conducted. It verified that Johnson-Cook model would describe the dynamic behavior of Al/PTFE reactive materials. The damage and the fracture of Al/PTFE under dynamic compression-shear loading was quantified well, and further was related to the ignition behavior observed during the tests. Finally, the dynamic compression-shear ignition mechanism of Al/PTFE reactive materials was revealed.

铝/聚四氟乙烯反应材料在动载荷作用下会发生着火。引燃机理涉及一个机械-热-化学耦合过程,引起了科学家和工程师的关注。然而,很难理解其机理,特别是在复杂载荷下。本文设计了3种不同形状的Al/PTFE试样,分别为0°圆柱体、30°斜圆柱体和45°斜圆柱体。采用分离式霍普金森压杆(SHPB)进行了动态点火试验。对其变形、损伤和断裂过程进行了分析。试样的力学响应取决于试样的形状,这决定了试样的动态压剪状态,进而导致不同的着火行为。提出了能量吸收率点火判据,取代了传统的应变率点火判据。新的标准可以很好地与测试相匹配。此外,还对SHPB进行了数值模拟。验证了Johnson-Cook模型能够描述Al/PTFE反应材料的动力学行为。动态压剪载荷对Al/PTFE的损伤和断裂进行了较好的量化,并进一步与试验中观察到的着火行为有关。最后,揭示了Al/PTFE反应材料的动态压缩-剪切点火机理。


Characterizing Damage Patterns and Evolution in Multi-Hole GLARE Laminates under Tensile Load via Integrated AE and DIC Techniques

Y.X. Zheng, K.J. Hu, M. Zhang, J.X. Zhu, F.L. Zhao, W.Q. Han, Q.H. Shi, Z.L. Cao

doi:10.1016/j.compstruct.2024.117911

基于声发射和DIC集成技术表征拉伸载荷下多孔眩光层合板的损伤模式和演化

In this study, a combined numerical simulation and experimental approach was employed to investigate the mechanical behavior and damage mechanisms of multi-hole GLARE laminates with varying off-axis angles under static tensile loading. Digital image correlation techniques were used to monitor changes in the strain field near the open hole region. The acoustic emission parameters were used to recognize damage patterns and evolution. The progressive damage evolution processes of various GLARE components were investigated using a 3D finite element model (FEM) based on the Hashin strain criterion and cohesive zone modeling. The results indicate that GLARE experiences damage modes such as aluminum alloy breakage, matrix cracking, fiber/matrix debonding, delamination, and fiber breakage. The frequency ranges associated with the five damage modes are as follows: [0-50 kHz], [100-175 kHz], [175-220 kHz], [220-300 kHz], and [300-400 kHz]. The dominant damage mode throughout the tensile phase is matrix cracking, but the ultimate failure of the specimen is determined by aluminum alloy breakage and fiber breakage. In addition, increasing the off-axis angle of the multi-hole leads to a shift in the final failure mode from tensile-dominated to tensile shear-dominated, while also slightly reducing the overall initial stiffness of the specimen.

采用数值模拟与实验相结合的方法,研究了不同离轴角的多孔眩光层压板在静态拉伸载荷作用下的力学行为和损伤机理。利用数字图像相关技术监测裸眼区域附近应变场的变化。利用声发射参数识别损伤模式和演化过程。采用基于Hashin应变准则和黏聚区建模的三维有限元模型,研究了不同眩光组件的渐进损伤演化过程。结果表明,眩光材料经历了铝合金断裂、基体开裂、纤维/基体脱粘、分层和纤维断裂等损伤模式。与五种损伤模式相关的频率范围如下:[0-50 kHz], [100-175 kHz], [175-220 kHz], [220-300 kHz]和[300-400 kHz]。拉伸阶段的主要破坏方式是基体断裂,但最终破坏是由铝合金断裂和纤维断裂决定的。此外,增加多孔离轴角会导致最终破坏模式从拉伸为主转变为拉伸剪切为主,同时也会使试件的整体初始刚度略有降低。


Auxetic Composite Absorbers based on foam-filled chiral frames for energy absorption in localized impact

Chuanqing Chen, Alessandro Airoldi, Antonio Maria Caporale, Giuseppe Sala, Xiaochun Yin

doi:10.1016/j.compstruct.2024.117916

基于泡沫填充手性框架的消声复合材料局部冲击吸能研究

In this paper, an innovative concept is proposed, based on the hexachiral auxetic frames filled with foams with enhanced energy absorption capabilities. Numerical assessments of the composite foam-filled auxetic absorbers, of pure foam blocks and unfilled auxetic frames for metallic and polymeric material combinations were accomplished considering a case of localized impact. The energy absorbed by the composite absorbers are found superior to the sum of the energies absorbed by constituent elements tested separately with clear advantages also at the level of the specific energy absorbed per unit mass. The interactions between the two constituents are analyzed and discussed. An experiment considering a 3D-printed polymeric hexachiral frame filled with open-cell soft polyurethane foam under localized impact is conducted to validate the numerical approach. Eventually, a parametric sensitivity study is conducted numerically to illustrate the effects of geometrical parameters on the energy absorption capacity. Overall, the results confirm the potential and the great design flexibility of the concept, provides the guidelines to design advanced energy absorbing system, underlies the importance of the combination between the frame and foam properties and the effect of the main geometrical parameters on the performance.

在此基础上,提出了一种具有增强吸能能力的泡沫填充六手性减振框架的创新概念。考虑局部碰撞情况,对金属和高分子材料组合的泡沫填充消声吸波器、纯泡沫块和未填充消声框架进行了数值评估。发现复合吸收剂吸收的能量优于单独测试的组成元素吸收的能量总和,在单位质量吸收的比能量水平上也具有明显的优势。分析和讨论了这两种成分之间的相互作用。以开孔软质聚氨酯泡沫塑料填充的3d打印聚合物六手体框架为研究对象,进行了局部冲击实验,验证了数值方法的有效性。最后,进行了参数敏感性数值研究,以说明几何参数对能量吸收能力的影响。总体而言,结果证实了这一概念的潜力和巨大的设计灵活性,为设计先进的吸能系统提供了指导,揭示了框架和泡沫性能之间结合的重要性以及主要几何参数对性能的影响。


Composites Part B: Engineering

Towards sustainable reprocessable structural composites: Benzoxazines as biobased matrices for natural fibers

Guillem Seychal, Louis Van Renterghem, Connie Ocando, Leila Bonnaud, Jean-Marie Raquez

doi:10.1016/j.compositesb.2024.111201

迈向可持续的可再加工结构复合材料:苯并恶嗪作为天然纤维的生物基基质

In this work, we synthesized and investigated three fully biobased benzoxazine matrices containing exchangeable ester bonds for natural fiber composites. The thermoset properties were investigated and the transesterification behavior was assessed. The obtained polymers show high tunability. Using isosorbide as the starting building block, the thermoset exhibits a glass transition of 130 °C, a tensile modulus of 2.5 GPa, and thermal stability leading to degradation occurring after 270 °C with 31% char at 800 °C. All formulations stress relax under catalyst-free conditions within an hour with properties recovery superior to 80%. Finally, flax composites were manufactured. We highlight strong affinities between the matrices and the fibers through high mechanical performances with a modulus over 30 GPa and stress at break of 400 MPa in the longitudinal direction. 5 GPa modulus and 47 MPa stress at break were found in the transverse direction. Excellent fire retardancy properties, with self-extinguishment and UL-94 V1 classification were obtained for the isosorbide-based/flax composite. The obtained composites were able to be welded with comparable results to glued ones, paving the way to processable laminates and stable cured prepreg perfectly suited for transportation-engineered applications.

在这项工作中,我们合成并研究了三种含交换酯键的全生物基苯并恶嗪基天然纤维复合材料。对其热固性进行了研究,并对其酯交换行为进行了评价。所得聚合物具有较高的可调性。使用异山梨酯作为起始构件,热固性材料表现出130°C的玻璃化转变,拉伸模量为2.5 GPa,热稳定性导致270°C后发生降解,800°C下炭化31%。在无催化剂条件下,所有配方在1小时内应力松弛,性能恢复优于80%。最后,制备了亚麻复合材料。我们通过高力学性能(模量超过30 GPa,纵向断裂应力为400 MPa)突出了基质和纤维之间的强亲和力。横向模量为5 GPa,断裂应力为47 MPa。结果表明,异山梨酯基/亚麻复合材料具有良好的自熄性和UL-94 V1级阻燃性能。所获得的复合材料能够焊接,其结果与粘合的结果相当,为可加工的层压板和稳定的固化预浸料铺平了道路,非常适合运输工程应用。


Engineered nanocomposites through embedding of smaller “organic inorganic” nanoparticles in thermoplastic Poly(2-Vinylpyridine) polymer matrix

Sanju Gupta, Alex Henson

doi:10.1016/j.compositesb.2024.111207

通过在热塑性聚(2-乙烯基吡啶)聚合物基体中嵌入更小的“有机无机”纳米颗粒来设计纳米复合材料

Polymer nanocomposites (PNCs) are significant for modern and future applications owing to their multifunctionality promoted by morphology and tailored interfaces between the constituents. However, ‘forward’ engineered polymer (host) composites with smaller size nanoparticles (guest) providing desired properties remains challenging as they depend upon nanoparticles aggregation, size, shape, and loading (volume or weight) fraction. This study strategically designs and develops PNCs comprising thermoplastic poly (2-vinylpyridine) (P2VP) polymer matrix impregnated with spherical polyhedral oligomeric silsesquioxane (N-POSS) nanoparticles (diameter ∼2–5 nm) and anisotropic planar nitrogenated graphene nanoribbons (GNR, strip width ∼5–10 nm) commensurate with polymer chain radius of gyration, Rg, (or segment length ∼1.5 nm) and comparable energy scales of electrostatic interaction and attractive hydrogen bonding. We investigated static and dynamic structure and thermophysical properties to correlate with interfacial regions and the results are compared with larger graphene oxide (GO, lateral dimension ∼100–200 nm) nanosheets and silica (SiO2, ∼25–50 nm) particles. While electron microscopy revealed nanoparticle distribution, the lattice bonding, conjugation length, and mechanical properties are determined from micro-Raman spectroscopy and atomic force microscopy, respectively. The differential scanning calorimetry provided a measure of glass transition temperature, Tg, with positive shift of ∼10–18 °C with nanoparticles loading indicating strength of structural relaxation/chain rigidity behavior and thermogravimetric analysis displayed increased thermal stability and conductivity (decreased interfacial resistance). We also measured temperature dependent dc electrical conductivity and dielectric relaxation spectroscopy gaining insights into percolation and dynamic interfacial layer. This study signified understanding of interactions and interfacial regions, key element to demystify the microscopic structure-property relationships.

聚合物纳米复合材料(pnc)由于其形态和成分之间的定制界面而具有多功能性,在现代和未来的应用中具有重要意义。然而,采用更小尺寸纳米颗粒(客体)的“正向”工程聚合物(主体)复合材料提供所需的性能仍然具有挑战性,因为它们取决于纳米颗粒的聚集、尺寸、形状和负载(体积或重量)分数。本研究战略性地设计和开发了pnc,包括热塑性聚(2-乙烯基吡啶)(P2VP)聚合物矩阵,其中浸染了球形多面体低聚硅氧烷(N-POSS)纳米颗粒(直径~ 2-5 nm)和各向异性平面氮化石墨烯纳米带(GNR,条带宽度~ 5 - nm),与聚合物链的旋转半径Rg(或片段长度~ 1.5 nm)相当,并具有可比较的静电相互作用和吸引氢键的能量尺度。我们研究了与界面区域相关的静态和动态结构以及热物理性质,并将结果与较大的氧化石墨烯(GO,横向尺寸~ 100-200 nm)纳米片和二氧化硅(SiO2, ~ 25-50 nm)颗粒进行了比较。电子显微镜显示了纳米颗粒的分布,微拉曼光谱和原子力显微镜分别测定了晶格键、共轭长度和力学性能。差示扫描量热法提供了玻璃化转变温度Tg的测量值,其正位移为~ 10-18 °C,纳米颗粒加载表明结构松弛/链刚性行为的强度,热重分析显示热稳定性和导电性增加(界面阻力降低)。我们还测量了温度相关的直流电导率和介电弛豫光谱,从而深入了解渗透和动态界面层。这一研究对了解相互作用和界面区域是揭开微观结构-性质关系的关键因素。


Composites Science and Technology

Efficient degradation of amine cured epoxy resin via the cleavage of C-N bond by amphiphilic dodecylbenzenesulfonic acid

Chizhou Wang, Ning Zhang, Shaodi Wu, Weijie Wang, Peng Zhao, Shiyu Jia, Yongqin Qi, Xianglin Hou, Xiaojing Cui, Tiansheng Deng

doi:10.1016/j.compscitech.2024.110442

 

两亲性十二烷基苯磺酸裂解C-N键高效降解胺固化环氧树脂

Amine-cured epoxy resin (EP) is often compounded with carbon fiber (CF) used for wind power blades due to its excellent performance. However, the insolubility and infusibility of service-life-expired carbon fiber reinforced epoxy resin (CFREP) hinder its sustainable recycling. We reported a new strategy for efficient degradation of EP and CFREP with 0.5 mol% amphiphilic dodecylbenzenesulfonic acid (DBSA) in aqueous system. It was found that the strong lipophilicity of DBSA accelerated its enrichment on EP surface, and further promoted the diffusion of DBSA and H2O to the resin bulk phase. As a result, the degradation ratio of the EP powder reached 100 % at 190 °C only in 10 h. The characterization of FT-IR and NMR proved that the degradation mechanism of EP was the selective cleavage of C-N bond catalyzed by H+. The resin degradation products (RDP) containing active hydrogen were used to prepare polyurethane (PU) with good mechanical properties. This method achieves complete recycling of waste CFREP in aqueous systems.

胺固化环氧树脂(EP)由于其优异的性能,常与碳纤维(CF)复合用于风力发电叶片。然而,碳纤维增强环氧树脂(CFREP)的不溶性和可灌注性阻碍了其可持续回收利用。本文报道了用0.5 mol%两亲性十二烷基苯磺酸(DBSA)在水溶液中高效降解EP和CFREP的新策略。发现DBSA的强亲脂性加速了其在EP表面的富集,进一步促进了DBSA和H2O向树脂体相的扩散。结果表明,在190 ℃下,仅10 h, EP粉末的降解率就达到了100% %。FT-IR和NMR表征证明了EP的降解机制是h +催化C- n键的选择性裂解。采用含活性氢的树脂降解产物(RDP)制备了具有良好力学性能的聚氨酯(PU)。该方法实现了水系统中废弃CFREP的完全回收。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemDeform断裂复合材料碰撞化学电子ADS焊接材料试验
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首次发布时间:2024-11-05
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【新文速递】2024年1月20日复合材料SCI期刊最新文章

今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 3 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 6 篇Composite StructuresInvestigations on the dynamic snap-through of MFC bonded self-resetting bistable laminatesP.M. Anilkumar, S. Scheffler, A. Haldar, E.L. Jansen, B.N. Rao, R. Rolfesdoi:10.1016/j.compstruct.2024.117906MFC键合自复位双稳态层合板的动态断通研究Unsymmetric composite laminates having two stable equilibrium configurations have been studied extensively in the recent past due to their potential applications in morphing structures. Surface bonded Macro Fiber Composites (MFC) actuators have been considered as a viable solution to trigger the snap-through transition in bistable laminates. Although MFC bonded bistable laminates are widely used in morphing applications, they might require considerably high voltage inputs to achieve the required levels of actuation control during the shape transition. As a solution, other possible energy sources can be combined with active MFC patches to reduce the snap-through energy required from the single source of MFC actuation. In this work, we examine the dynamic behavior of bistable composite plates actuated using MFC actuators, where external vibration energy has been used to assist with the MFC-controlled actuation between stable states. A refined semi-analytical model based on the Rayleigh–Ritz formulation has been proposed, where the membrane energy and the bending energy are separately evaluated. Bending components are directly evaluated using the approximated transverse displacement functions, whereas the membrane components are evaluated separately by combining compatibility conditions and equilibrium equations. Results from the proposed semi-analytical framework are compared with a full geometrically non-linear finite element framework and necessary experimental observations. The results show a significant reduction in the snap-through energy demand on MFC layers where external dynamic excitation assists the snap-through process. Additionally, a parametric study is performed using variable stiffness (VS) fiber orientation parameters, achieving bistable laminate-MFC configurations that lower snap-through requirements through the proposed morphing strategy. Thus, the study offers to aid a multi-efficient snap-through strategy for the morphing of multistable composite structures.具有两种稳定平衡结构的非对称复合材料层压板由于其在变形结构中的潜在应用,近年来得到了广泛的研究。表面粘合宏纤维复合材料(MFC)促动器被认为是触发双稳态层合板的通断过渡的可行解决方案。虽然MFC键合双稳态层压板广泛应用于变形应用,但它们可能需要相当高的电压输入才能在形状转变期间实现所需的驱动控制水平。作为一种解决方案,其他可能的能量来源可以与有源MFC贴片相结合,以减少MFC驱动的单一来源所需的穿透能量。在这项工作中,我们研究了使用MFC致动器驱动的双稳态复合材料板的动态行为,其中外部振动能量被用来辅助MFC控制的稳定状态之间的致动。提出了一种基于瑞利-里兹公式的改进半解析模型,其中膜能和弯曲能分别进行了评估。弯曲分量直接用近似的横向位移函数来计算,而膜分量则通过结合相容性条件和平衡方程来单独计算。所提出的半解析框架的结果与完整的几何非线性有限元框架和必要的实验观测结果进行了比较。结果表明,在外部动态激励辅助snap-through过程的MFC层上,snap-through能量需求显着降低。此外,使用可变刚度(VS)纤维方向参数进行了参数化研究,通过提出的变形策略实现了双稳态层压板- mfc配置,降低了卡通要求。因此,该研究为多稳定复合材料结构的变形提供了一种多高效的snap-through策略。Composites Part A: Applied Science and ManufacturingBasalt fibre degradation in seawater and consequences for long term composite reinforcementLouis Le Gué, Peter Davies, Mael Arhant, Benoit Vincent, Wouter Verbouwedoi:10.1016/j.compositesa.2024.108027 玄武岩纤维在海水中的降解及其对长期复合材料增强的影响Basalt fibres are increasingly employed as reinforcements in marine composites, but their behaviour in natural marine environments is underexplored. This study investigates basalt fibre ageing in renewed natural seawater at 15 °C and 40 °C. After one month in seawater at 15 °C and 40 °C, tensile strength dropped, stabilizing at approximately −40% and −60%, respectively. This rapid initial property decline, followed by slower degradation, is attributed to an altered surface layer on the fibres. Initially causing significant property loss, this layer then plays a protective role, preserving the fibre core. The impact on basalt/epoxy composites exposed to 7.5 years of seawater was less severe, with a 20% loss at 40 °C, demonstrating the protective function of the matrix. This study suggests that basalt fibres undergo rapid, then stable, property degradation in water, but remain suitable for use as epoxy matrix composite reinforcements, thanks to the protective role of the resin.玄武岩纤维越来越多地被用作海洋复合材料的增强材料,但其在自然海洋环境中的行为尚未得到充分研究。本文研究了玄武岩纤维在15°C和40°C再生天然海水中的老化情况。在15°C和40°C海水中浸泡一个月后,抗拉强度下降,分别稳定在- 40%和- 60%左右。这种最初性能的快速下降,随后是较慢的降解,是由于纤维表面层的改变。最初造成显著的性能损失,这一层随后起保护作用,保存纤维芯。暴露在7.5年海水中的玄武岩/环氧复合材料受到的影响较小,在40°C时损失20%,证明了基体的保护功能。这项研究表明,玄武岩纤维在水中经历了快速而稳定的性能降解,但由于树脂的保护作用,它仍然适合用作环氧基复合材料增强材料。Particle morphology dependence of the mechanical and electrical properties in the in-situ graphene reinforced Cu matrix compositesXianlong Li, Baisong Guo, Xiang Yu, ChuangChuang Yang, Shengfeng Zhou, Shaogang Cui, Zhiguo Zhang, Wei Lidoi:10.1016/j.compositesa.2024.108032原位石墨烯增强铜基复合材料力学和电学性能的颗粒形态依赖性Five forms of Cu powders including dendritic, spherical, flake-mix, flake-mill and cake morphologies were designed to in-situ grow Gr on Cu powders using polymethyl methacrylate as a solid carbon precursor. The Gr/Cu composite bulk samples were subsequently prepared by a rapid electrical current hot-pressed sintering process. The results show that the multilayered Grs are obtained on the Cu particles with different morphologies and uniformly dispersed in the bulk Gr/Cu composites. The in-situ formed Gr is an effective reinforcement in Cu matrix composites to achieve enhancement in both microhardness and tensile strength. The bulk Gr/Cu composites from the dendritic Cu and flake Cu-mill powders exhibited a superior combination between strength, ductility and electrical conductivity, achieving enhancements of 14% and 27% in their tensile strengths while retaining a slight decrease in electrical conductivity when compared to pure Cu. These results would provide theoretical guidance and experimental instructions for preparing high-performance Gr reinforced Cu matrix composites.以聚甲基丙烯酸甲酯为固体碳前驱体,设计了枝晶、球形、片状混合、片状磨粒和饼状五种形态的Cu粉,在Cu粉上原位生长Gr。随后采用快速电流热压烧结工艺制备了Gr/Cu复合材料体样。结果表明:在不同形貌的Cu颗粒上均可形成多层的Grs,并均匀分布在块状Gr/Cu复合材料中;在Cu基复合材料中,原位形成的Gr是一种有效的增强剂,可以同时提高材料的显微硬度和抗拉强度。枝晶Cu和片状Cu磨粉制备的大块Gr/Cu复合材料在强度、延展性和导电性方面表现出优异的组合,与纯Cu相比,其抗拉强度分别提高了14%和27%,而导电性却略有下降。研究结果为制备高性能Gr增强Cu基复合材料提供了理论指导和实验指导。Experimental characterisation and constitutive modelling of the intra-ply tensile and shear properties of unidirectional fibre reinforced thermoplastics (UD FRTPs) under solid-state stamp forming conditionsHongyan Wang, Zerong Ding, Xingtong Chen, Haibao Liu, Nan Lidoi:10.1016/j.compositesa.2024.108034 单向纤维增强热塑性塑料(UD FRTPs)在固态冲压成形条件下的拉伸和剪切性能的实验表征和本构建模To enable the success of solid-state stamp forming of unidirectional fibre reinforced thermoplastics (UD FRTPs), it is essential to accurately characterise and model the material deformation under desired conditions. This paper comprehensively investigates the intra-ply tensile and shear properties of unidirectional carbon fibre reinforced polyamide 6 (UD CF/PA6), which is a type of commonly used UD FRTP. To accomplish this, tensile and V-Notched Rail (VNR) shear tests are conducted for characterising the intra-ply transverse tensile and longitudinal shear properties, respectively. The temperature effects (180 – 220 ℃, at 0.01 /s for the transverse tensile deformation and at 0.04 /s for longitudinal shear deformation) and strain-rate effects (0.001 – 0.25 /s for transverse tensile deformation and 0.004 – 0.4 /s for the longitudinal shear deformation, both are at 200 ℃) are studied. It is found that temperature has significant effects on the intra-ply deformation properties, while the strain-rate effects are marginal. This paper also proposes a new physically based constitutive model considering all the deformable constituents, i.e., the polymer constituent reinforced by fibres (PrF) and the polymer-fibre interface (P-F). This model not only shows good prediction of the thermomechanical properties of UD CF/PA6 under intra-ply deformations, but also gives insights into the deformation mechanisms. The new physically based constitutive model is successfully embedded into Finite Element Analysis (FEA) software and validated through accurate prediction of intra-ply deformation of a CF/PA6 specimen under bias-extension. The methodologies and model developed here offer an effective tool for predicting the intra-ply deformation behaviours and guiding the solid-state stamp forming process of UD FRTPs.为了使单向纤维增强热塑性塑料(UD FRTPs)的固态冲压成形成功,在所需条件下准确表征和模拟材料变形至关重要。本文对常用的单向碳纤维增强聚酰胺6 (UD CF/PA6)的层内拉伸和剪切性能进行了全面的研究。为此,分别进行了拉伸和v型缺口轨(VNR)剪切试验,以表征层内横向拉伸和纵向剪切特性。研究了温度效应(180 ~ 220℃,横向拉伸变形速度为0.01 /s,纵向剪切变形速度为0.04 /s)和应变速率效应(横向拉伸变形速度为0.001 ~ 0.25 /s,纵向剪切变形速度为0.004 ~ 0.4 /s,均为200℃)。结果表明,温度对层内变形性能有显著影响,而应变速率对层内变形性能影响较小。本文还提出了一种新的基于物理的本构模型,考虑了所有可变形组分,即纤维增强聚合物组分(PrF)和聚合物-纤维界面(P-F)。该模型不仅能很好地预测UD CF/PA6在层内变形下的热力学性能,而且对变形机理也有深入的了解。将基于物理的本构模型成功嵌入有限元分析(FEA)软件中,并通过准确预测CF/PA6试件在偏置拉伸下的层内变形进行验证。本文开发的方法和模型为预测UD frtp的层内变形行为和指导固态冲压成形过程提供了有效的工具。Composites Part B: EngineeringBioinspired semi-flexible hydrogel with anti-inflammatory potential for natural tissue-mimicking bone regenerationJae Seo Lee, Hyo-Sung Kim, Haram Nah, Ho-Jin Moon, Na Re Ko, Sang Jin Lee, Wan-Kyu Ko, Sun Hee Do, Dong Nyoung Heo, Il Keun Kwondoi:10.1016/j.compositesb.2024.111223 仿生半柔性水凝胶,具有抗炎潜力,用于自然组织模拟骨再生Three-dimensional (3D) scaffolds are typically created to replace damaged tissues and mimic the stiffness of the target tissue. It is now well established that cells respond to the stiffness of these scaffolds. In this study, we developed a semi-flexible hydrogel to mimic natural tissue and facilitate bone regeneration. The hydrogel was designed to transition gradually from soft to hard, resembling the stiffness of the target tissue. We achieved strong bonding with adjacent tissues by crosslinking fibrinogen (FBG), inspired by blood clotting at wound sites. Additionally, we utilized the mechanism of collagen (COL) to create a hydrogel that consumes energy and changes its internal state with body temperature. The composite hydrogel promoted energy dissipation by strengthening the elastic fibers of FBG through COL, forming a dense structure. The hydrogel's hydrophilic surface initially facilitated rapid cell adhesion, and as cells penetrated the inner part, they became rigid, contributing to bone tissue formation. Furthermore, the modified hydrogel's stiffness and surface affinity reduced inflammation during early stages of regeneration. Overall, our bioinspired semi-flexible hydrogel offers a promising strategy for mimicking natural tissue, reducing inflammation, and bridging defects during bone regeneration.三维(3D)支架通常用于替换受损组织并模拟目标组织的刚度。现在已经确定细胞对这些支架的硬度有反应。在这项研究中,我们开发了一种半柔性水凝胶来模拟自然组织并促进骨再生。水凝胶被设计成从软到硬逐渐过渡,类似于目标组织的硬度。受伤口部位血液凝固的启发,我们通过交联纤维蛋白原(FBG)实现了与邻近组织的强结合。此外,我们利用胶原蛋白(COL)的机制创造了一种水凝胶,它消耗能量并随着体温改变其内部状态。复合水凝胶通过冷强化光纤光栅弹性纤维,促进能量耗散,形成致密结构。水凝胶的亲水表面最初促进了细胞的快速粘附,当细胞渗透到内部时,它们变得坚硬,有助于骨组织的形成。此外,改性水凝胶的硬度和表面亲和力减少了早期再生阶段的炎症。总的来说,我们的仿生半柔性水凝胶提供了一种很有前途的策略,可以模拟自然组织,减少炎症,并在骨再生过程中桥接缺陷。Composites Science and TechnologyJoint interface optimization of all-CFRTP composite honeycomb prepared by ultrasonic multi-spot weldingJunxian Xiang, Jie Tao, Funa Yang, Huaguan Li, Xi Chen, Yanyan Lin, Lili Yuandoi:10.1016/j.compscitech.2024.110456 超声多点焊接制备全cfrtp蜂窝复合材料接头界面优化An all carbon fiber reinforced polyetheretherketone (CF/PEEK) composite honeycomb is prepared by the multi-spot ultrasonic welding in this work. The interfacial responses and flat compression failure behaviors of the honeycomb are firstly analyzed. It is found that ultrasonic welding has both positive and negative effects on honeycomb performance. High-frequency vibration results in fiber waviness, which is beneficial to elevating both the bending resistance of the joints and the compression strength of the honeycomb. However, melted EDs also lead to resin-rich areas at the interface. Based on the findings, the multiwall carbon nanotubes/PEEK (MWCNTs/PEEK) energy directors are developed, providing new insights on optimizing the properties of the interface. The experimental results indicate that the interfacial node tensile strength is enhanced by 400 % (1267 kPa) with the MWCNTs content increasing to 7.5 wt%, and the optimized CF/PEEK honeycomb shows more superior specific energy absorption and specific compressive strength than those of the commercial light-weight honeycombs. Moreover, the joint failure behaviors are investigated thoroughly. The addition of MWCNTs is found to induce fiber bridging between the cell walls and facilitate stress transfer through the joint interface. The optimized ultrasonic welding method provides a new opportunity for efficient and volume manufacturing of carbon fiber reinforced composite honeycombs without dimension limitation and large mold costs.采用多点超声焊接法制备了全碳纤维增强聚醚醚酮(CF/PEEK)复合蜂窝材料。首先分析了蜂窝结构的界面响应和扁压破坏行为。结果表明,超声焊接对蜂窝材料的性能既有积极影响,也有消极影响。高频振动使纤维呈波纹状,有利于提高接头的抗弯性能和蜂窝的抗压强度。然而,熔化的EDs也会在界面处形成富含树脂的区域。在此基础上,开发了多壁碳纳米管/PEEK (MWCNTs/PEEK)能量总监,为优化界面性能提供了新的见解。实验结果表明,当MWCNTs含量增加到7.5 wt%时,界面节点抗拉强度提高了400 %(1267 kPa),且优化后的CF/PEEK蜂窝比能吸收和比抗压强度优于商品轻质蜂窝。此外,还对接头的破坏行为进行了深入的研究。研究发现,添加MWCNTs可诱导细胞壁之间的纤维桥接,并促进应力通过关节界面传递。优化后的超声焊接方法为无尺寸限制、模具成本高的碳纤维增强复合材料蜂窝的高效批量制造提供了新的契机。Synergistic of UV resistant water-borne polyurethane sizing with metal chelation to enhance the interfacial properties of CF/PA6 compositesYanan Zhao, Shengtao Dai, Weibing Pei, Jiaming Guo, Longxuan Gao, Yuhui Ao, Weifeng Du, Huiling Xu, Yu Liu, Liu Liudoi:10.1016/j.compscitech.2024.110449 耐紫外线水性聚氨酯浆料与金属螯合剂的协同作用提高CF/PA6复合材料的界面性能Currently, the challenge of achieving robust adhesion between carbon fibers and resins remains a focal point for exploring composites. This study introduces a waterborne polyurethane sizing agent employing natural biomass derived sodium alginate as the foundational material. The infusion of 4,4-dihydroxybenzophenone as a chain ext ender imparts the sizing agent with ultraviolet (UV) absorption capabilities. Additionally, chelation between Ca2+ and sodium alginate was harnessed to amplify the interfacial adhesion between the fibers and sizing agent, thereby fostering a more tenacious connection for the two entities and fortifying the fiber-resin interface. The ramifications of varying sizing agent concentrations on composite materials were methodically explored. Comparative analysis conducted against untreated CF composites discloses noteworthy enhancements in the interlaminar shear strength (ILSS) by 46 %, bending strength by 67 %, and interface shear strength (IFSS) by 57 % for CF-1.5 wt%/PA6 composites. Notably, even after enduring a week of xenon lamp aging, the mechanical integrity preserved at approximately 98 %. This inventive methodology presents a fresh avenue for bolstering the characteristics of CF composites.目前,实现碳纤维和树脂之间牢固粘合的挑战仍然是探索复合材料的焦点。介绍了一种以天然生物质衍生海藻酸钠为基础材料的水性聚氨酯施胶剂。注入4,4-二羟基二苯甲酮作为链引出剂,使施胶剂具有紫外吸收能力。此外,Ca2+和海藻酸钠之间的螯合作用被用来增强纤维和施胶剂之间的界面粘附,从而促进两个实体之间更牢固的连接,并加强纤维-树脂界面。系统地探讨了不同施胶剂浓度对复合材料的影响。与未经处理的CF复合材料进行的对比分析显示,CF-1.5 wt%/PA6复合材料的层间剪切强度(ILSS)提高了46 %,弯曲强度提高了67 %,界面剪切强度(IFSS)提高了57 %。值得注意的是,即使在氙灯老化一周后,机械完整性仍保持在98% %左右。这种创造性的方法为增强CF复合材料的特性提供了新的途径。3D printed bio-inspired self-similar carbon fiber reinforced composite sandwich structures for energy absorptionYonglin Chen, Zhengyi Jin, Wenbin Kang, Zhuangjian Liu, Weidong Yang, Yan Lidoi:10.1016/j.compscitech.2024.110453 3D打印仿生自相似碳纤维增强复合材料夹层结构的能量吸收Fractals widely found in nature possess amazing simple shape cell yet infinitely complex macrostructures. Importantly, all fractals manifest a degree of self-similarity that provides new structural design strategy for composite materials. At present, enhancing energy absorption capacity of lightweight carbon fiber reinforced composite structures is critical for their further engineering applications, and meanwhile biomimetic structures have demonstrated excellent mechanical properties compared to conventional engineering structures. In this work, we constructed bio-inspired fractal structures through three fundamental shape units (curve, circle, and hexagon), and investigated nonlinear mechanical responses of hierarchical self-similar structures inspired by snake-like serpentine, bamboo, and honeycomb, having distinct structure ratios related to cell sizes at different geometry levels. Firstly, such self-similar structures were fabricated into homogenous ones by 3D printing for assessing the energy dissipation contribution of polymer matrix. Moreover, the selected self-similar carbon fiber reinforced composites were additively manufactured and their energy absorption mechanisms of composite sandwich structures were studied via experiment and numerical methods. Additionally, the influences of the self-similar types, structure ratios, and cellular scales on nonlinear compressive behaviors of self-similar composite structures were investigated in detail. The results indicated that the fractal bamboo composite components with the structure ratio of 0.2 exhibit the highest energy absorption rates, with a satisfactory level of energy absorption capacity in potential engineering applications. This study can provide a useful reference in the field of biomimetic fractal design of fiber reinforced composite structures by 3D printing technique.自然界中广泛存在的分形具有极其简单的细胞形状和极其复杂的宏观结构。重要的是,所有分形都表现出一定程度的自相似性,为复合材料提供了新的结构设计策略。目前,提高轻质碳纤维增强复合材料结构的吸能能力是其进一步工程应用的关键,与此同时,仿生结构与传统工程结构相比已表现出优异的力学性能。在这项工作中,我们通过三种基本形状单元(曲线、圆形和六边形)构建了仿生分形结构,并研究了受蛇形、竹子和蜂窝启发的分层自相似结构的非线性力学响应,这些结构在不同几何水平上具有与细胞大小相关的不同结构比例。首先,利用3D打印技术将这种自相似结构制作成均匀结构,以评估聚合物基体的能量耗散贡献;采用增材制备了自相似碳纤维增强复合材料,并通过实验和数值方法研究了复合材料夹层结构的吸能机理。此外,还详细研究了自相似类型、结构比和细胞尺度对自相似复合材料结构非线性压缩行为的影响。结果表明,结构比为0.2的分形竹复合材料构件的吸能率最高,具有较好的工程应用潜力。该研究可为3D打印技术在纤维增强复合材料结构的仿生分形设计领域提供有益的参考。Construction of cellulose nanofiber/carbon nanotube synergistic network on carbon fiber surface to enhance mechanical properties and thermal conductivity of compositesGuipeng Quan, Yunhuan Wu, Weiwen Li, Daimei Li, Xudong Liu, Kui Wang, Shengtao Dai, Linghan Xiao, Yuhui Aodoi:10.1016/j.compscitech.2024.110454 在碳纤维表面构建纤维素纳米纤维/碳纳米管协同网络,提高复合材料的力学性能和导热性Drawing inspiration from the robustness and resilience of spider silk, this study harnessed a combination of polydopamine (PDA), cellulose nanofibers (CNFs), polyvinyl alcohol (PVA), and aminated carbon nanotubes (CNTs) to create a synergistic network through hydrogen and covalent bonding on the surface of carbon fibers (CFs). This strategy significantly bolstered the interfacial properties of the resulting composites. The enhancements in flexural strength, flexural modulus, interlaminar shear strength (ILSS), tensile strength, and interfacial shear strength (IFSS) were measured at 47.8 %, 75.2 %, 54.3 %, 55.6 %, and 51.8 %, respectively. These improvements are attributed to the formation of robust covalent and hydrogen bonds among PDA, CNF, PVA, and aminated CNTs. Furthermore, the thermal conductivity of the CF composites saw a 59.7 % increase, owing to the CNFs and CNTs. These nanofillers are instrumental in forming an efficient thermal conductivity pathway within the resin matrix, which contributes to the improved thermal conductivity. This study introduces a straightforward, eco-friendly, and innovative approach for the production of high-performance CF composites.从蜘蛛丝的坚固性和弹性中获得灵感,本研究利用聚多巴胺(PDA)、纤维素纳米纤维(CNFs)、聚乙烯醇(PVA)和胺化碳纳米管(CNTs)的组合,通过碳纤维(CFs)表面的氢和共价键来创建一个协同网络。这一策略显著增强了复合材料的界面性能。抗弯强度、抗弯模量、层间抗剪强度(ILSS)、抗拉强度和界面抗剪强度(IFSS)的提高分别为47.8% %、75.2% %、54.3% %、55.6% %和51.8 %。这些改进是由于PDA、CNF、PVA和胺化碳纳米管之间形成了牢固的共价键和氢键。此外,由于CNFs和CNTs的加入,CF复合材料的导热系数提高了59.7% %。这些纳米填料有助于在树脂基体内形成有效的导热途径,从而有助于提高导热性。本研究介绍了一种简单、环保、创新的生产高性能CF复合材料的方法。Machine-learning-assisted multiscale modeling strategy for predicting mechanical properties of carbon fiber reinforced polymersGuomei Zhao, Tianhao Xu, Xuemeng Fu, Wenlin Zhao, Liquan Wang, Jiaping Lin, Yaxi Hu, Lei Dudoi:10.1016/j.compscitech.2024.110455 碳纤维增强聚合物力学性能预测的机器学习辅助多尺度建模策略Carbon fiber reinforced polymers (CFRPs) possess light weight and high strength, making them highly attractive for various applications. However, the design parameter space of CFRPs is extensive, with the complex relationship between structures and mechanical properties. Traditional design methods that rely on trial and error or scientific intuition are laborious and expensive for achieving optimal properties of CFRPs. In light of this challenge, we proposed a machine-learning-assisted multiscale modeling strategy that can efficiently predict the mechanical properties of CFRPs. This strategy uses low-computational-cost machine learning (ML) models to replace traditional theoretical models and combines them with molecular dynamics simulation to predict the mechanical properties of CFRPs starting from resin molecules. Comparing predicted values with the proof-of-concept experiment and the existing experimental findings showed that the predicted values of the ML model are in good agreement with the experimental ones. This strategy can be a viable machine-learning-assisted solution to designing CFRPs.碳纤维增强聚合物(CFRPs)具有重量轻、强度高的特点,在各种应用中具有很高的吸引力。然而,碳纤维frp的设计参数空间广泛,结构与力学性能之间的关系复杂。传统的设计方法依靠试错法或科学直觉来实现cfrp的最佳性能,既费力又昂贵。针对这一挑战,我们提出了一种机器学习辅助的多尺度建模策略,可以有效地预测cfrp的力学性能。该策略使用低计算成本的机器学习(ML)模型取代传统的理论模型,并将其与分子动力学模拟相结合,从树脂分子开始预测cfrp的力学性能。将模型预测值与概念验证实验和已有实验结果进行比较,结果表明模型预测值与实验值吻合较好。这种策略可以作为设计cfrp的可行的机器学习辅助解决方案。Highly sensitive porous PDMS-based piezoresistive sensors prepared by assembling CNTs in HIPE templateLanxin Li, Jingqian Deng, Peng Kong, Wei Zou, Zhongjie Du, Hong Wang, Chen Zhangdoi:10.1016/j.compscitech.2024.110459 通过在HIPE模板中组装碳纳米管制备高灵敏度多孔pdms压阻传感器With the rapid development of the application in health-monitors and wearable devices, the demand for the piezoresistive sensors with both high flexibility and high sensitivity has been growing. In this work, a porous carbon nanotubes/polydimethylsiloxane (CNTs/PDMS) composite was prepared by high internal phase emulsion (HIPE) template. The PDMS foam with tens of micrometers of pores offered high flexibility and elasticity. Moreover, guided by cetyltrimethylammonium bromide (CTAB) in HIPE, CNTs were selectively distributed in inner pores’ surface of the foam, and then the 3D conductive network was constructed. As a result, the stress of the foam was 107.1 kPa at 60 % compressive strain and the electrical conductivity reached 9.77×10−5 S m−1, when the volume fraction of CNTs was 1 vol%. Finally, the flexible conductive foam was applied for a piezoresistive sensor. The sensor exhibited a high gauge factor (GF = 24.15) and a wide working range (0∼60 %). Furthermore, the human movements, such as finger bending and walking, were detected by as-prepared piezoresistive sensor, and a good response was obtained.随着压阻式传感器在健康监测和可穿戴设备中应用的迅速发展,对高灵活性和高灵敏度的压阻式传感器的需求越来越大。本研究采用高内相乳液(HIPE)模板制备了多孔碳纳米管/聚二甲基硅氧烷(CNTs/PDMS)复合材料。具有数十微米孔隙的PDMS泡沫具有很高的柔韧性和弹性。此外,在HIPE中十六烷基三甲基溴化铵(CTAB)的引导下,将碳纳米管选择性地分布在泡沫的内孔表面,构建三维导电网络。结果表明,当CNTs体积分数为1 vol%时,当压缩应变为60 %时,泡沫的应力为107.1 kPa,电导率为9.77×10−5 S m−1。最后,将柔性导电泡沫材料应用于压阻式传感器。该传感器具有高的测量因子(GF = 24.15)和宽的工作范围(0 ~ 60 %)。利用所制备的压阻式传感器对人体的手指弯曲、行走等动作进行检测,获得了良好的响应。来源:复合材料力学仿真Composites FEM

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