今日更新:Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 3 篇,Composites Science and Technology 2 篇Composites Part A: Applied Science and ManufacturingThe influence of impact-induced damage on electromagnetic shielding behaviour of carbon fibre reinforced polymer compositesE. Mikinka, T. Whittaker, P. Synaszko, W. Whittow, G. Zhou, K. Dragandoi:10.1016/j.compositesa.2024.108464 冲击损伤对碳纤维增强聚合物复合材料电磁屏蔽性能的影响Increasing interest in multifunctional carbon fibre reinforced polymer (CFRP) composite structures for electromagnetic (EM) shielding prompts discussions on their EM shielding durability. Herein, the EM shielding effectiveness (SE) of impact damaged and artificial delamination conditioned CFRP laminates was characterised and compared to intact specimens. The SE in two frequency regimes was investigated: the UHF (0.03–1.5 GHz) and Ka band (26–42 GHz). The lower frequency SE experiments demonstrated a positive effect of impact delamination, ascribed to the enhanced absorption caused by multiple reflections. Concurrently, owing to the reduced skin depth, severe damage involving fibre fracture was required to induce noticeable SE changes at higher frequencies. The effect of artificial delamination was a strong function of the lay-up, with a significant deterioration in thin cross-ply laminates due to the impaired contribution of through-the-thickness conduction loss. The lower frequency results were simulated in CST Microwave Studio, demonstrating good agreement with experimental values.碳纤维增强聚合物(CFRP)复合材料多功能电磁屏蔽结构引起了人们对其电磁屏蔽耐久性的讨论。本文对冲击损伤和人工分层条件CFRP层合板的电磁屏蔽效能(SE)进行了表征,并与完整样品进行了比较。研究了UHF(0.03-1.5 GHz)和Ka(26-42 GHz)两个频段的SE。低频SE实验表明,由于多次反射引起的吸收增强,冲击分层具有积极作用。同时,由于皮肤深度减少,需要纤维断裂的严重损伤才能在较高频率下引起明显的SE变化。人工分层的影响是铺层的一个强大功能,由于通过厚度传导损失的贡献受损,薄交叉层合板的性能显著恶化。在CST Microwave Studio中对低频结果进行了模拟,结果与实验值吻合较好。Composites Part B: EngineeringEffect of Field's metal particles coated with PVA, nano-SiO2 and PVA@nano-SiO2 on the performance of cement pastesCheng QIAN, Zhaocai ZHANG, Yu ZHUdoi:10.1016/j.compositesb.2024.111823菲尔德金属颗粒包覆PVA、纳米sio2和PVA@nano-SiO2对水泥浆体性能的影响In this paper, a modification method for physical surface coating of Field's metal particles (FMP) using individual/combined polyvinyl alcohol (PVA) and nano-silica (NS) is proposed. The properties of cement pastes modified by FMP@H2O, FMP@PVA, FMP@PVA@NS, FMP@NS were evaluated by mechanical test, EIS, NMR, XRD, TG, and SEM. The results showed that the flexural strength and compressive strength of cement pastes with FMP@PVA, FMP@PVA@NS, FMP@NS at 7 days increased 2.74∼13.01 % and 9.18∼18.10 %, respectively, compared to the control samples, due to the inhibition of calcium hydroxide (CH) nucleation crystallization in the connection region between FMP and matrix by PVA, and CH reacting with NS to generate CSH gels. The cement paste with FMP@PVA has the best matrix strength at 28 days, resulting from the optimized connection region. Additionally, the mechanism of modified FMP strengthening connection region was proposed to explain the uniform distribution of FMP in fresh state, and the directional growth of CH crystals, which has a good agreement with the results of mechanical properties, phase analysis, thermal analysis and SEM observation. In accordance with the research in this paper, FMP as a new functional raw material is expected to be applied in the mix design of large-volume concrete, oil-gas well cement, and geothermal cement, especially used for temperature self-regulation and crack self-healing of cementitious materials.本文提出了一种用单独/复合聚乙烯醇(PVA)和纳米二氧化硅(NS)改性菲尔德金属粒子(FMP)物理表面涂层的方法。采用力学试验、EIS、NMR、XRD、TG、SEM等方法对FMP@H2O、FMP@PVA、FMP@PVA@NS、FMP@NS改性水泥膏体的性能进行了评价。结果表明,与对照样品相比,FMP@PVA、FMP@PVA@NS、FMP@NS水泥浆体的抗折强度和抗压强度在7 d时分别提高了2.74 ~ 13.01%和9.18 ~ 18.10%,这是由于PVA抑制了FMP与基质连接区域的氢氧化钙(CH)成核结晶,以及CH与NS反应生成CSH凝胶。掺FMP@PVA的水泥浆体在28 d时基质强度最佳,这是由优化的连接区域产生的。此外,提出了改性FMP强化连接区的机理,解释了FMP在新鲜状态下的均匀分布和CH晶体的定向生长,这与力学性能、物相分析、热分析和SEM观察结果吻合较好。根据本文的研究,FMP作为一种新型的功能原料,有望应用于大体积混凝土、油气井水泥、地热水泥的配合比设计,特别是用于胶凝材料的温度自调节和裂缝自愈合。Stretchable supramolecular hydrogel with instantaneous self-healing for electromagnetic interference shielding control and sensingKunpeng Qian, Jianyu Zhou, Miao Miao, Sineenat Thaiboonrod, Jianhui Fang, Xin Fengdoi:10.1016/j.compositesb.2024.111826 具有瞬时自愈的可拉伸超分子水凝胶,用于电磁干扰屏蔽控制和传感Conductive hydrogels possess instantaneous self-healing and adhesive properties have generated great excitement in the fields of sensing and electromagnetic interference (EMI) shielding. In this study, we ingeniously designed hydrogel-based soft materials with high conductivity by using poly(vinyl alcohol) (PVA), positively charged Ti3C2Tx MXene and thioctic acid (TA) as source materials. Through concentration-induced ring-opening polymerization of TA monomers in an aqueous solution of potassium hydroxide (KOH), supramolecular poly(potassium thioctate) (poly(PT)) was obtained. Then, the multifunctional poly(PT)/PVA/p-MXene hydrogel with exceptional stretchability, substrate-adhesion and self-healing capability was achieved through abundant dynamic bonds, including disulfide bonds, hydrogen bonds, coordination bonds and electrostatic interactions. The hydrophobic main chains within poly(PT) provide robust protection against the oxidative degradation of MXene. This hydrogel shows outstanding strain sensing and extraordinary EMI shielding effectiveness (SE) of 48.56 dB caused by the inner structure, conductivity, and water content. Interestingly, the EMI SE can be regulated by reabsorbing moisture from the air, thereby enabling the reuse of dried hydrogel. Furthermore, the EMI SE can be dynamically modulated through controlled deformations, confirming the potential application for electromagnetic waves (EMWs) sensing. This innovative approach not only simplifies the fabrication of multifunctional materials but also expands the applications of adhesive hydrogels with conductivity.导电水凝胶具有瞬时自愈和粘接特性,在传感和电磁干扰屏蔽领域引起了极大的关注。本研究以聚乙烯醇(PVA)、带正电的Ti3C2Tx MXene和硫辛酸(TA)为原料,巧妙地设计了具有高导电性的水凝胶基软材料。通过在氢氧化钾水溶液中对TA单体进行浓度诱导开环聚合,得到了超分子聚硫辛酸钾(PT)。然后,通过丰富的动态键,包括二硫键、氢键、配位键和静电相互作用,获得了具有优异拉伸性、底物粘附性和自修复能力的多功能聚(PT)/PVA/p-MXene水凝胶。聚(PT)中的疏水主链对MXene的氧化降解提供了强大的保护。由于其内部结构、电导率和含水量,该水凝胶具有出色的应变传感和非凡的电磁干扰屏蔽效果(SE),达到48.56 dB。有趣的是,EMI SE可以通过从空气中重新吸收水分来调节,从而使干燥的水凝胶能够重复使用。此外,EMI SE可以通过控制变形进行动态调制,证实了电磁波(EMWs)传感的潜在应用。这种创新的方法不仅简化了多功能材料的制造,而且扩展了具有导电性的粘接水凝胶的应用。A hydro-thermo-chemo-mechanical model for slag-blended cementitious systems at early agesJun Wang, Zhangli Hu, Jian Zhang, Hua Li, Jiaping Liudoi:10.1016/j.compositesb.2024.111830早期矿渣混合胶凝体系的水-热-化学-力学模型A comprehensive hydro-thermo-chemo-mechanical model for predicting the early-age properties development of slag-blended cementitious systems is presented in this study. A new kinetics evolution for slag reaction that takes into account the heterogeneous nucleation effect and induction time of slag was proposed, with which the model effectively quantifies the contributions of slag to the hydration, energy exchange and mass conversation within blended systems. This paper provides a thorough documentation of input parameters, fundamental equations, and constitutive laws associated with the model. The hydro-thermo-chemo-mechanical model successfully predicts the heat release, hydration degrees of cement and slag, self-desiccation, basic creep and autogenous shrinkage in slag-blended cementitious systems. The predictions align well with the experimental observation obtained from this work and reported works in the literature, validating the accuracy and reliability of the proposed model in capturing and explaining the complex early-age behaviors of slag-blended cementitious systems.本文提出了一种综合的水-热-化学-力学模型,用于预测矿渣混合胶凝体系的早期性能发展。提出了考虑矿渣非均相成核效应和诱导时间的矿渣反应动力学演化模型,该模型有效地量化了矿渣对混合体系水化、能量交换和质量转化的贡献。本文提供了一个彻底的文件输入参数,基本方程,并与模型相关的本构律。水-热-化学-力学模型成功地预测了水泥-矿渣混合胶凝体系的放热、水化程度、自干燥、基本徐变和自收缩。这些预测与本研究获得的实验观察结果以及文献中报道的工作相吻合,验证了所提出模型在捕获和解释渣混合胶凝体系复杂的早期行为方面的准确性和可靠性。Composites Science and TechnologyA progressive optimization of axial compression performance of 3D angle-interlock tubular woven composites through textile structure and yarn configuration innovationsRui Xu, Jiaye Wang, Wei Zhang, Hailou Wangdoi:10.1016/j.compscitech.2024.110864 通过织物结构和纱线配置创新,逐步优化三维角互锁管编织复合材料轴向压缩性能Lightweight tubular composite materials with excellent compression performance are important structural components for load-bearing or energy absorption. Generally, outstanding performance depends on the structural design. Herein, a progressive structural optimization of 3D angle-interlock tubular woven reinforced composites (3DATWCs) is performed. The structural factors under consideration involve proportion of warp lining yarn, layers of weft yarn, surface constraint yarn and weft density. The axial compression performance and failure process of 3DATWCs with different structures are investigated through experiments and finite element method. The results indicate that increasing proportion of warp lining yarn can significantly improve the axial compression performance of 3DATWC. However, simply increasing proportion of warp lining yarn may decrease the straightness of yarn and constraint on warp yarns, leading to the performance reduction. The problem of performance reduction can be solved by introducing surface constraint yarn or increasing weft density. Finally, an optimization strategy is unveiled. Compared to ordinary structure, the ultimate load, plateau average load, ultimate stress, elastic modulus, total energy absorption and specific energy absorption of optimized 3DATWC increase by 101.88%, 96.12%, 77.46%, 142.55%, 119.06%, and 77.39%, respectively. Additionally, the axial compression performance is seriously affected by the fiber waviness, yarn waviness and interfacial properties, and can be further improved through reducing the waviness during the preparation of fabric preform.轻质管状复合材料具有优异的压缩性能,是承载或吸能的重要结构部件。一般来说,优异的性能取决于结构设计。在此基础上,对三维角互锁管编织增强复合材料(3DATWCs)进行了渐进式结构优化。考虑的结构因素包括经纱衬纱比例、纬纱层数、表面约束纱和纬密度。通过试验和有限元分析,研究了不同结构的3DATWCs轴压性能和破坏过程。结果表明,增加经纱衬里纱的比例,可以显著提高3DATWC的轴压性能。而单纯增加经衬纱的比例,会降低纱线的直线度和对经纱的约束,导致性能下降。通过引入表面约束纱或增加纬纱密度,可以解决性能下降的问题。最后,提出了优化策略。与普通结构相比,优化后的3DATWC极限荷载、平台平均荷载、极限应力、弹性模量、总能量吸收和比能量吸收分别提高了101.88%、96.12%、77.46%、142.55%、119.06%和77.39%。此外,纤维的波纹度、纱线的波纹度和界面性能对轴向压缩性能有严重影响,在织物预成型的制备过程中可以通过降低波纹度来进一步提高轴向压缩性能。Graphene-based hierarchical structure for significantly enhancing thermal conductivity of composites with high mechanical reinforcementXinyang Sun, Han Wang, Ni Lu, Jiangang Zhang, Chaoqun Ma, Xuhai Xiong, Zhenguo Zhu, Chang Liu, You Zengdoi:10.1016/j.compscitech.2024.110865 基于石墨烯的层次化结构显著提高了复合材料的导热性,具有较高的机械强度Significant enhancement in out-of-plane thermal conductivity of carbon fiber/epoxy laminated composites without sacrificing mechanical strength is of great challenge for advanced composites. In this study, a novel graphene-based hierarchical structure was constructed by combining graphene foams (GrFs) with graphene nanoplatelets (GNPs) together and laminating with carbon fiber (CF) fabrics. The GrFs acted as thermally-conductive skeletons in bridging CF fabrics together to remarkably increase out-of-plane thermal conductivity of composites, while the GNPs were helpful to further increasing heat-transfer paths and effectively transferring stress between continuous CFs for high mechanical reinforcement. The hierarchical composites exhibited extremely high out-of-plane thermal conductivity of 2.64 W/m·K, increasing by 158.8% than that of CF/Ep composites, and they also showed satisfactory tensile, flexural, and interlaminar shear strength. Such high performance is mainly due to the hierarchical structure, continuous heat-transfer paths, synergetic enhancement of GrFs with GNPs, and strong interfacial interactions between components for high-efficiency heat and stress transfer.如何在不牺牲机械强度的前提下显著提高碳纤维/环氧层合复合材料的面外导热系数是目前先进复合材料面临的一大挑战。在这项研究中,将石墨烯泡沫(GrFs)与石墨烯纳米片(GNPs)结合在一起,并与碳纤维(CF)织物复合,构建了一种新型的石墨烯基分层结构。GrFs作为桥接CF织物的导热骨架,显著提高复合材料的面外导热系数,而GNPs有助于进一步增加传热路径,并有效地在连续CF织物之间传递应力,从而获得高机械增强。层叠复合材料的面外导热系数为2.64 W/m·K,比CF/Ep复合材料提高了158.8%,并且具有良好的拉伸、弯曲和层间剪切强度。这主要得益于其层次化的结构、连续的传热路径、GrFs与GNPs的协同增强以及组分之间强的界面相互作用,从而实现高效的热应力传递。来源:复合材料力学仿真Composites FEM