【新文速递】2024年9月21日固体力学SCI期刊最新文章

今日更新：Composite Structures 1 篇，Composites Part A: Applied Science and Manufacturing 2 篇，Composites Part B: Engineering 8 篇，Composites Science and Technology 2 篇Composite StructuresOn the interlaminar mode II fracture toughness evaluation of glass Fiber/Epoxy composites adding cotton and kenaf natural fibers Applying acoustic emission featuresAli Daemi, Seyed Reza Hamzeloo, Amir Refahi Oskoueidoi:10.1016/j.compstruct.2024.118591应用声发射特征评价添加棉花和红麻天然纤维的玻璃纤维/环氧复合材料的层间II型断裂韧性Considering the widespread use of polymer composites due to their diverse engineering properties, the incorporation of natural fibers is a novel approach to enhance their environmental properties and acquire additional engineering benefits. Applying natural fibers in composites can offer a biocompatible solution to plastic and polymer composite waste issues. Studying the overall properties of composites made with these fibers is a novel area of research. Investigating effective methods for detecting defects and measuring mechanical properties, such as integrity, resilience to failure, and fracture toughness, is particularly crucial. In the current study, the effect of adding cotton and kenaf natural fibers on the resistance to delamination, which is the most common type of failure in laminated composites, is investigated in mode Ⅱ of loading. Specimens of woven glass/epoxy composites with natural fibers were fabricated using the hand lay-up method and end notched three-point bending test was performed. Using the methods provided in the JIS K 7086 standard, the moment of initiation of delamination is determined in the samples. The results demonstrate that only using the mechanical methods provided in the mentioned standard is not sufficient to determine the initiation of delamination. Hence, the acoustic emission can be employed for an easier and more accurate determination of the initiation of delamination. According to the obtained results, cotton and kenaf fibers show a significant increase in the interlaminar fracture toughness of woven glass/epoxy composites. Using cotton fibers shows 212% − 249% and employing kenaf fibers shows 144% − 281% increase in interlaminar fracture toughness respectively. Among the different acoustic emission data analytics, the cumulative energy method shows the lowest mean percentage deviation error of %2.59 among other examined diagnosing techniques.考虑到聚合物复合材料由于其多样化的工程性能而被广泛使用，天然纤维的掺入是提高其环境性能和获得额外工程效益的一种新方法。在复合材料中应用天然纤维可以为塑料和聚合物复合材料废物问题提供生物相容的解决方案。研究由这些纤维制成的复合材料的整体性能是一个新的研究领域。研究检测缺陷和测量机械性能的有效方法，如完整性、失效回弹性和断裂韧性，尤为重要。在加载模式Ⅱ下，研究了添加棉花和红麻天然纤维对层合复合材料抗分层性能的影响，这是层合材料中最常见的破坏类型。采用手工铺层法制备了天然纤维编织玻璃/环氧复合材料试件，并进行了端缺口三点弯曲试验。使用JIS k7086标准中提供的方法，测定样品中的分层起始力矩。结果表明，仅使用上述标准中提供的力学方法不足以确定分层的开始。因此，声发射可以用于更容易和更准确地确定分层的起始。结果表明，棉花和红麻纤维的加入显著提高了玻璃/环氧复合材料的层间断裂韧性。棉纤维和红麻纤维的层间断裂韧性分别提高212% ~ 249%和144% ~ 281%。在不同的声发射数据分析方法中，累积能量法的平均百分比偏差误差最小，为%2.59。Composites Part A: Applied Science and ManufacturingEffect of geometry and adhesion on the performance of fiber reinforced thermoplastic composite joints with metal insertsMuhammad Ridha, Zhoucheng Su, Le Quan Ngoc Tran, Wei Ming Albert Yek, Sridhar Narayanaswamy, Tong Earn Taydoi:10.1016/j.compositesa.2024.108482几何形状和黏附对金属镶块纤维增强热塑性复合材料接头性能的影响Joints for laminated composite structures using mechanical fasteners or adhesives often face issues such as reduced strength from fiber breakage in mechanically fastened joints and complex preparation for adhesive joints. Additionally, adhesive joints require compatibility between the adhesive and the composite matrix, limiting their suitability for many thermoplastics. To address these challenges, this study explores a technique that uses metal inserts embedded during the consolidation of laminated thermoplastic composites. It investigates how the geometry of metal inserts and their adhesion to the fiber-reinforced thermoplastic composite affect the joint’s performance under out-of-plane loads. Results indicate that while mechanical locking assists in load transfer, the adhesion between the metal insert and the composite is crucial for the joint’s failure mechanism and overall performance. Strong adhesion delays final failure by requiring fiber breakage through the composite’s entire thickness, while weak adhesion leads to failure through fiber breakage on the bearing side.采用机械紧固件或胶粘剂的层压复合材料结构接头经常面临机械紧固接头中纤维断裂导致强度降低和胶粘剂接头制备复杂等问题。此外，粘合接头需要粘合剂和复合基体之间的相容性，这限制了它们对许多热塑性塑料的适用性。为了解决这些挑战，本研究探索了一种技术，在层压热塑性复合材料的巩固过程中使用嵌入的金属插入物。研究了金属嵌套的几何形状及其与纤维增强热塑性复合材料的粘附性如何影响关节在面外载荷下的性能。结果表明，虽然机械锁紧有助于载荷传递，但金属镶件与复合材料之间的粘附对接头的破坏机制和整体性能至关重要。强附着力通过要求纤维在复合材料的整个厚度上断裂来延缓最终的破坏，而弱附着力通过在轴承侧断裂纤维导致最终的破坏。A nanomodified-ultrasonic method to improve the shear strength of adhesively bonded composite jointsWei Feng, Le Chang, Jiamu He, Zheng Dai, Xintong Shi, Wei Xie, Fei Xudoi:10.1016/j.compositesa.2024.108483一种提高粘接复合材料接头抗剪强度的纳米改性超声方法Adhesive bonding method has become prevalent in joining composite structures in the aerospace and automotive industries. The bonding quality is critical in terms of service safety. This research proposed a nanomodified-ultrasonic method to enhance the shear strength of adhesively composite joints. Functional multi-walled carbon nanotubes (MWCNTs) were dispersed into the adhesive, followed by the ultrasonic vibration during the bonding process. Orthogonal experiments considering different combinations of the NWCNT concentrations, ultrasonic power, and ultrasonic time were conducted to investigate the effect of different factors and to obtain the optimal processing parameters. Results indicate that the nanomodified-ultrasonic method is beneficial to the composite bonded joint and a maximum increase of 75.1% in shear strength was achieved. Furthermore, the bondline before testing and fracture surface were critically analyzed to illustrate the enhancement mechanisms.在航空航天和汽车工业中，粘接方法已成为连接复合材料结构的普遍方法。粘接质量对使用安全至关重要。本研究提出了一种纳米改性超声方法来提高粘接复合材料接头的抗剪强度。功能型多壁碳纳米管(MWCNTs)被分散到胶粘剂中，粘接过程中伴随着超声振动。通过正交试验考察不同浓度、超声功率、超声时间组合对纳米碳纳米管的影响，得出最佳工艺参数。结果表明:纳米改性-超声处理有利于复合材料粘结接头的抗剪强度提高75.1%;此外，对测试前的结合线和断口表面进行了严格分析，以说明增强机制。Composites Part B: EngineeringSynergistically enhanced PVDF-based nanofiber membranes randomly embedded with ZnWO4@PDA nanorods for self-powered sensors with multi-mode free switchingHui Wang, Haijiao Lin, Shuhong Huang, Ling Li, Youwei Zhao, Wenming Zhangdoi:10.1016/j.compositesb.2024.111841 随机嵌入ZnWO4@PDA纳米棒的协同增强pvdf基纳米纤维膜用于多模自由开关自供电传感器In spite of the high level of attention paid to multifunctional sensors, the flexible and multifunctionality are still intractable challenges to be tackled. Herein, we design a flexible, hydrophobic and stable multifunctional sensing material by electrostatic spinning of PVDF/ZnWO4@PDA (PZP). The incorporation of ZnWO4@PDA into PVDF nanofibers can act as an effective nucleating agent and photosensitizer, which increases the polar crystalline phase and photovoltaic properties of PVDF. With the synergy of PVDF and ZnWO4@PDA, PZP based piezoelectric sensors offer significantly superior electrical output (28.4 V, 600 nA) and high sensitivity (1.04 V/kPa). Moreover, it is particularly surprising that photoelectric sensor based on PZP textiles has excellent optical properties, as confirmed by the response/recovery time (0.6 s/0.66 s) of simulated sunlight detection. Piezoelectric photoelectric effect exists in PZP textiles, as evidenced by the significant increase in the strain output current of photoelectric sensor when irradiated with sunlight. Furthermore, based on the coupling of piezoelectric effect and triboelectric effect of PZP composite, the contact out nano-triboelectric generator has enhanced the electrical output and electromechanical conversion efficiency. Therefore, this work has successfully prepared multifunctional sensing materials that integrate pressure sensing, audio recognition, underwater communication, optoelectronic detection and triboelectric energy collection, paving a new way for the flexible multifunctional sensors.尽管多功能传感器受到高度重视，但其灵活性和多功能性仍然是一个亟待解决的难题。本文采用PVDF/ZnWO4@PDA (PZP)静电纺丝的方法，设计了一种柔性、疏水、稳定的多功能传感材料。ZnWO4@PDA加入到PVDF纳米纤维中可以作为有效的成核剂和光敏剂，提高了PVDF的极性晶相和光伏性能。通过PVDF和ZnWO4@PDA的协同作用，基于PZP的压电传感器提供了显著优越的电输出(28.4 V, 600 nA)和高灵敏度(1.04 V/kPa)。此外，基于PZP纺织品的光电传感器具有优异的光学性能，模拟太阳光检测的响应/恢复时间(0.6 s/0.66 s)证实了这一点。PZP纺织品中存在压电光电效应，在阳光照射下光电传感器应变输出电流显著增加。此外，基于压电效应和摩擦电效应的耦合，接触式输出纳米摩擦发电机提高了电输出和机电转换效率。因此，本工作成功制备了集压力传感、音频识别、水下通信、光电探测和摩擦电能收集为一体的多功能传感材料，为柔性多功能传感器的发展开辟了新的道路。Flexible cellulose nanofiber-Fe3O4/liquid metal/graphene composite films with hierarchical gradient structure for efficient electromagnetic interference shielding and thermal managementSong Yang, Ying Zhang, Yilin Liu, Ting Gu, Fei Liudoi:10.1016/j.compositesb.2024.111844 具有分层梯度结构的柔性纤维素纳米纤维- fe3o4 /液态金属/石墨烯复合薄膜，用于高效电磁干扰屏蔽和热管理The development of flexible multifunctional composite films that simultaneously combine high electromagnetic interference (EMI) shielding and effective thermal management is urgently needed, yet it remains an extremely challenging task to meet the increasingly complex service requirements of integrated electronic devices, especially in the field of flexible wearable electronic products. Herein, a novel flexible composite film consisting of cellulose nanofibers/Fe3O4, cellulose nanofiber/liquid metal, and cellulose nanofibers/graphene nanoplatelets (CNF/Fe3O4&CNF/LM&CNF/GNPs) with a hierarchical gradient structure was fabricated using a vacuum filtration and cool-pressing technique. Benefitting from its unique hierarchical gradient structure design, the CNF composite film exhibits high electrical conductivity of 22.42 S cm-1, excellent EMI shielding effectiveness of 36.21 dB (with a thickness of only 0.18 mm), outstanding in-plane thermally conductivity of 8.98 W (m K)-1, and a fast electric-heating response. Furthermore, the CNF composite film also displays exceptional mechanical properties, with a strong tensile strength of 55.26 MPa and a toughness of 2.72 MJ m-3, due to the good deformability of LM and the formation of a “zigzag” crack path. This strategy holds promise for the manufacture of dual-function flexible composite films that exhibit excellent thermal conductivity and EMI shielding performance, with potential applications in portable electronic devices, artificial intelligence, communication equipment, and other relevant fields.开发兼具高电磁干扰屏蔽和有效热管理的柔性多功能复合薄膜是迫切需要的，但要满足集成电子器件日益复杂的使用需求，特别是在柔性可穿戴电子产品领域，仍然是一项极具挑战性的任务。本文采用真空过滤和冷压技术制备了一种由纤维素纳米纤维/Fe3O4、纤维素纳米纤维/液态金属和纤维素纳米纤维/石墨烯纳米片(CNF/Fe3O4和CNF/LM&CNF/GNPs)组成的具有分层梯度结构的新型柔性复合膜。得益于其独特的分层梯度结构设计，CNF复合膜具有22.42 S cm-1的高电导率，36.21 dB的优秀EMI屏蔽效能(厚度仅为0.18 mm)， 8.98 W (m K)-1的出色面内导热率和快速的电热响应。此外，由于LM具有良好的可变形性和“之字形”裂纹路径的形成，CNF复合膜表现出优异的力学性能，抗拉强度达到55.26 MPa，韧性达到2.72 MJ m-3。该策略有望制造出具有优异导热性和EMI屏蔽性能的双功能柔性复合薄膜，在便携式电子设备、人工智能、通信设备和其他相关领域具有潜在的应用前景。Synthesis of a novel biomass-based flame retardant featuring vinyl-terminated chemical cross-linking and application in flame retardancy, smoke suppression, toxicity reduction and mechanical enhancement of PAN composite fibersChunlong Zuo, Wei Tan, Jieyun Zhao, Lina Jiang, Yongli Zhang, Yuanlin Ren, Xiaohui Liudoi:10.1016/j.compositesb.2024.111846 端乙烯基化学交联新型生物质阻燃剂的合成及其在PAN复合纤维阻燃、抑烟、降毒和力学增强方面的应用To develop green and efficient polyacrylonitrile (PAN) fibers with excellent fire safety properties, a new biomass-based flame retardant (PPC@VA) with vinyl-terminated groups was prepared based on the reaction of hexachlorocyclotriphosphonitrile, teat polyphenols, ethylenediamine and vinylphosphoric acid. Subsequently, it was mixed with spinning solution to obtain PPC@VA/PAN through wet spinning, which were then chemically cross-linked via thermal initiation to achieve CC-PPC@VA/PAN fibers. CC-PPC@VA/PAN showed a significant improvement in flame retardancy with a limiting oxygen index value of 32.5%. The peak of smoke production rate, total smoke production and CO production rate were lowered by 81.9%, 77.8% and 91.3%. Besides, the hazardous gas HCN was greatly suppressed. Owing to the macromolecular entanglement, hydrogen bonding and covalent cross-linking, CC-PPC@VA/PAN improved elongation at break and tensile strength by 19.2% and 72.1%. Also, chemical cross-linking contributed to decrease the migration of P/N-based flame retardants, lower the potential risk of water eutrophication and increased the service life of the fibers.为开发具有优异防火性能的绿色高效聚丙烯腈(PAN)纤维，以六氯环三膦腈、茶多酚、乙二胺和乙烯基磷酸为原料，制备了端乙烯基阻燃剂(PPC@VA)。随后，将其与纺丝液混合，通过湿法纺丝得到PPC@VA/PAN，再通过热引发化学交联得到CC-PPC@VA/PAN纤维。CC-PPC@VA/PAN的阻燃性能显著提高，极限氧指数达到32.5%。产烟率、总产烟率和CO产烟率峰值分别降低81.9%、77.8%和91.3%。对有害气体HCN的抑制作用明显。通过高分子缠结、氢键和共价交联，CC-PPC@VA/PAN的断裂伸长率和抗拉强度分别提高了19.2%和72.1%。化学交联有助于减少P/ n基阻燃剂的迁移，降低水体富营养化的潜在风险，提高纤维的使用寿命。Diisocyanate-induced covalent cross-linking of MXene frameworks for electrically and mechanically robust EMI shielding filmsSeongeun Lee, Tae Yun Ko, Junpyo Hong, Albert S. Lee, Jae-Seung Lee, Seon Joon Kimdoi:10.1016/j.compositesb.2024.111847二异氰酸酯诱导的MXene框架的共价交联，用于电和机械上坚固的EMI屏蔽膜MXenes, two-dimensional transition metal carbides, nitrides, and carbonitrides, have emerged as versatile materials with remarkable physicochemical properties. However, their vulnerability to delamination or degradation in humid or liquid environments poses challenges for long-term stability. In this study, we present a novel approach to enhance MXene stability by synthesizing electrically conductive frameworks through covalent cross-linking using diisocyanates such as 1,4-phenylene diisocyanate (PDI) and hexamethylene diisocyanate (HDI). The resulting frameworks exhibit well-aligned MXene sheets covalently bonded throughout the film. The frameworks not only retained high electrical conductivity but also exhibited improved tensile strength and elongation at break compared to pristine MXene films. Moreover, the frameworks demonstrated exceptional stability under ultrasonic treatment in water, showing their enhanced structural durability. The chemically cross-linked MXene frameworks exhibited hydrophobicity and resistance to water, which contributed to their prolonged chemical stability as well. EMI shielding performance at Ka-band and X-band frequencies was comparable to pristine MXene films, in which SET values around 60 dB were retained in oxidative environments over a week these findings open avenues for the development of robust MXene-based materials with enhanced stability for diverse applications, including electromagnetic interference shielding.MXenes是一种二维过渡金属碳化物、氮化物和碳氮化物，是一种具有显著物理化学性质的多用途材料。然而，它们在潮湿或液体环境中容易分层或降解，这对其长期稳定性构成了挑战。在这项研究中，我们提出了一种新的方法，通过使用二异氰酸酯如1,4-苯基二异氰酸酯(PDI)和六亚甲基二异氰酸酯(HDI)通过共价交联合成导电框架来提高MXene的稳定性。所得到的框架在整个薄膜中呈现出共价键合的排列良好的MXene薄片。与原始MXene薄膜相比，该框架不仅保持了高导电性，而且表现出更高的拉伸强度和断裂伸长率。此外，框架在水中超声波处理下表现出优异的稳定性，显示出其增强的结构耐久性。化学交联的MXene骨架具有疏水性和耐水性，这也有助于其延长化学稳定性。在ka波段和x波段频率下的EMI屏蔽性能与原始MXene薄膜相当，其中SET值在氧化环境中保持约60 dB超过一周。这些发现为开发坚固的MXene基材料开辟了道路，该材料具有增强的稳定性，可用于各种应用，包括电磁干扰屏蔽。Multi-functional Finishing of Viscose Fabrics Based on Tea Polyphenols: Integrated Flame Retardant, Antibacterial, Hydrophobic, and UV-resistant FunctionalitiesWan-Meng Song, Li-Yao Zhang, Ru-Yu Fan, Yun Liu, Yu-Zhong Wangdoi:10.1016/j.compositesb.2024.111848基于茶多酚的粘胶织物多功能整理:集阻燃、抗菌、疏水和抗紫外线功能于一体Tea polyphenols (TP) are endowed with numerous outstanding properties due to their natural structure, and their use in the preparation of multifunctional finishing agents is a novel topic. In this paper, a multifunctional finishing agent, PAT, was prepared by using phytic acid and TP as raw materials and finished on the surface of viscose fabrics to obtain PAT-100. After measurement, the limiting oxygen index of PAT-100 achieved 32.9%, and the peak heat release rate was reduced by 90%. Due to the presence of polyphenolic groups, PAT exhibited excellent inhibitory effects on Staphylococcus aureus and Escherichia coli, and the UPF value was improved to 53.2. Furthermore, this system also improved the hydrophobicity of viscose fabrics, and the breaking force retention in the warp and weft directions reached 130% and 156%, respectively. This work presents new ideas for TP in the field of multifunctional finishing and increases the added value of viscose fabrics.茶多酚因其天然的结构而具有许多优异的性能，在制备多功能整理剂中的应用是一个新颖的课题。本文以植酸和TP为原料，制备了一种多功能整理剂PAT，并将其涂布在粘胶织物表面，得到了PAT-100。经测定，PAT-100的极限氧指数达到32.9%，峰值放热率降低90%。由于多酚基团的存在，PAT对金黄色葡萄球菌和大肠杆菌表现出良好的抑制作用，UPF值提高到53.2。此外，该体系还提高了粘胶织物的疏水性，经纬方向的断裂力保持率分别达到130%和156%。本研究为涤棉在多功能整理领域的应用提供了新的思路，提高了粘胶织物的附加值。Green and Sustainable Bamboo Based Composites with High Self-Bonding StrengthYongzhong Wu, Layun Deng, Fangyu Zhu, Qunying Mou, Xiazhen Li, Lin He, Yong Wang, Zhiyong Cai, Zheng Yu, Siyang Ji, Xianjun Lidoi:10.1016/j.compositesb.2024.111849具有高自粘强度的绿色可持续竹基复合材料Self-bonding technology is a forming method utilized for the production of bio-composites with notable advantages in terms of high strength and water resistance, while also being free from formaldehyde. The successful achievement of high-strength self-bonding biomaterials has been demonstrated, however, most of these achievements have relied on various surface chemical modifications with limited attention given to exploring non-additive approaches. This study aimed to investigate the feasibility of self-bonding formation through examining the effects of particle dispersion, lignin melting, and chemical bonding, in distinct unit morphologies without the use of any chemical additives. Also, the self-bonding mechanism of bamboo based composites (BBCs) was revealed, by examination of its microstructure, chemical composition and thermal stability. The findings indicated that raw component morphologies based on power, fiber, and bundle all effectively achieved high-strength self-bonding structures at a temperature of 155°C, a pressure of 55 MPa, and a duration time of 60 min. The density of the BBCs approached that of solid cell wall in bamboo, reaching a maximum of 1.44 g/cm3. The morphology of raw components had significant effect on the self-bonding performance of BBCs, with the powder exhibiting the highest performance, followed by the bundles, and the fibers showing the lowest. The powder-based BBC demonstrated a remarkable flexural strength of 61 MPa, a notable surface hardness of 32.5 kgf/mm and low 24 hr thickness swelling of 6.8%, all much more excellent than those observed in ordinary panels. The BBCs demonstrated the benefits of being environmentally friendly (free from formaldehyde), processing excellent water resistance and strong mechanical strengths. They were suitable for use in high-humidity environments and can meet the requirements for strong load-bearing conditions, even replacing some metal sliding bearing materials.自粘合技术是一种用于生产生物复合材料的成型方法，具有显著的高强度和耐水性，同时也不含甲醛的优点。高强度自结合生物材料的成功已经被证明，然而，这些成就大多依赖于各种表面化学修饰，对探索非添加剂方法的关注有限。本研究旨在探讨在不使用任何化学添加剂的情况下，通过考察颗粒分散、木质素熔化和化学键在不同单元形态下形成自键的可行性。通过对竹基复合材料微观结构、化学成分和热稳定性的分析，揭示了竹基复合材料的自粘合机理。结果表明，在155℃、55 MPa、60 min的温度条件下，基于功率、纤维和束的原始组分形态均能有效地形成高强度的自键结构，其密度接近竹的固体细胞壁密度，最大可达1.44 g/cm3。原料组分的形态对碳纳米管的自键性能有显著影响，其中粉末的自键性能最高，其次是束，纤维的自键性能最低。其抗折强度为61 MPa，表面硬度为32.5 kgf/mm, 24小时厚度溶胀率为6.8%，明显优于普通面板。BBCs展示了其环保(不含甲醛)、优异的耐水性和强大的机械强度等优点。它们适合在高湿度环境中使用，可以满足强承重条件的要求，甚至可以取代一些金属滑动轴承材料。Innovative binary Na0.5Bi0.5TiO3-based composite ceramics with excellent comprehensive energy storage performances under low electric fieldsChunhui Wu, Yongping Pu, Xiang Lu, Yating Ning, Lei Zhang, Bo Wang, Zhemin Chen, Pengfan Lv, Yongqiang Yang, Zhuo Wangdoi:10.1016/j.compositesb.2024.111853创新的二元na0.5 bi0.5 tio3基复合陶瓷，在低电场下具有优异的综合储能性能The insufficient energy storage properties (ESPs) of lead-free dielectric ceramics at low electric fields (E) hinder their applications in the integrated and miniaturized electronic equipment. From this perspective, a synergetic tactic for enhancing the ESPs of (1-x)(Na0.5Bi0.5)0.75Sr0.25TiO3-xCa(Mg1/3Ta2/3)O3 ceramics at low E is proposed by constructing composite ceramics in combination with the design of average ionic polarizability. Consequently, the best recorded ESPs (recoverable energy density Wrec ∼ 6.7 J/cm3 and energy efficiency η ∼ 92.5%) contrasted to other lead-free ceramics at the same E (260 kV/cm) are attained in the x = 0.15 ceramics. This is owing to the improved breakdown E caused by the second phase Bi4Ti3O12 and the retentive high-polarization characteristic of matrix. In addition, rapid discharge time (∼66.8 ns), excellent thermal (30 ∼ 130 °C) and frequency (1 ∼ 100 Hz) stability are also achieved. Hence, the present work offers an innovative insight into the optimization of comprehensive ESPs for dielectric ceramics at low E.无铅介电陶瓷在低电场（E）下的储能特性（ESP）不足，阻碍了它们在集成化和微型化电子设备中的应用。从这个角度出发，通过构建复合陶瓷并结合平均离子极化率的设计，提出了一种协同策略，以提高 (1-x)(Na0.5Bi0.5)0.75Sr0.25TiO3-xCa(Mg1/3Ta2/3)O3 陶瓷在低电场下的 ESPs。因此，在相同 E（260 kV/cm）下，x = 0.15 陶瓷的静电除尘器记录（可回收能量密度 Wrec ∼ 6.7 J/cm3，能量效率 η ∼ 92.5%）与其他无铅陶瓷相比最好。这是由于第二相 Bi4Ti3O12 提高了击穿 E 值，以及基体具有保持高极化特性。此外，还实现了快速放电时间（∼66.8 ns）、出色的热稳定性（30 ∼ 130 °C）和频率稳定性（1 ∼ 100 Hz）。因此，本研究为优化低 E 值介电陶瓷的综合静电除尘器提供了创新性见解。Sustainable Engineering Polymer Composites Fabricated Using Delignified Bamboo Fiber as Reinforcement and Walnut Shell Powder as FillerLe Li, Shouqing Liu, Guanben Du, Shuyang Jiang, Jing Yang, Jianli Zhang, Taohong Lidoi:10.1016/j.compositesb.2024.111857以去木质素竹纤维为增强材料，核桃壳粉为填料制备可持续工程高分子复合材料Developing sustainable engineering materials using renewable resources and agro-wastes represents an effective method for reducing carbon emissions and environmental pollution. In this study, a novel approach to fabricating high-performance biomass-based polymer composites was presented. Specifically, partially delignified bamboo fiber (DBF) and walnut shell powder (WSP) were incorporated into the matrix, namely melamine-hexamethylenediamine-urea (MHU) resin which was previously known for its excellent interfacial compatibility. Mechanical property investigations show that the DBF, acting as the reinforcement, provided the hybrid composites with high flexural and tensile strength up to 220 and 120 MPa, respectively, greatly surpassing those of commercial wood-plastic composites, wood-based composites, and natural wood, making them promising structural materials. As the filler, walnut shell powder endowed the composites with high hardness (Shore D > 90) and an appealing mirror-like surface gloss. Owing to the protection provided by the MHU matrix, the composite containing 38% MHU exhibited outstanding flame retardancy (UL 94-V0 grade), which was further supported by cone calorimeter test (CCT) results. An unexpected and intriguing finding is that the composites exhibited fluorescence under UV irradiation. The rare silvery-grey fluorescence color imparted self-anticounterfeiting property to the composites. This study demonstrated the significant potential of bamboo fiber and walnut shell in the development of sustainable engineering materials.利用可再生资源和农业废弃物开发可持续工程材料是减少碳排放和环境污染的有效方法。本研究提出了一种制备高性能生物质基聚合物复合材料的新方法。具体来说，将部分去木素化的竹纤维(DBF)和核桃壳粉(WSP)加入到基体中，即三聚氰胺-六亚甲二胺-尿素(MHU)树脂，这种树脂以前以其优异的界面相容性而著称。力学性能研究表明，DBF作为增强剂，使复合材料具有较高的抗弯强度和抗拉强度，分别达到220和120 MPa，大大超过了商用木塑复合材料、木基复合材料和天然木材，是一种很有前景的结构材料。核桃壳粉作为填料，使复合材料具有较高的硬度(邵氏D > 90)和极好的镜面光泽度。由于MHU基体的保护作用，含38% MHU的复合材料表现出优异的阻燃性(UL 94-V0级)，锥量热测试(CCT)结果进一步证实了这一点。一个意想不到的和有趣的发现是复合材料在紫外线照射下表现出荧光。罕见的银灰色荧光使复合材料具有自防伪性能。本研究表明竹纤维和核桃壳在可持续工程材料的开发中具有巨大的潜力。Composites Science and TechnologyThermal-mechanical-chemical coupled model and three-dimensional damage evaluation based on computed tomography for high-energy laser-ablated CFRPYaoran Li, Jiawei Chen, Shengyu Duan, Panding Wang, Hongshuai Lei, Zeang Zhao, Daining Fangdoi:10.1016/j.compscitech.2024.110867 高能激光烧蚀CFRP的热-机-化耦合模型及三维损伤评价High-energy laser is widely used for machining carbon fiber reinforced polymer (CFRP) composites because of their high precision and fine quality. However, the mechanism by which CFRPs are damaged by high-energy laser in processing is unclear. In this article, the coupled mechanism of laser-ablated CFRPs is investigated experimentally and theoretically. The three-dimensional morphology of laser-damaged CFRPs is captured by computed tomography (CT), which quantitatively characterizes the degree of pyrolytic charring and internal delamination. Accordingly, a thermal-mechanical-chemical coupled model is established considering the matrix pyrolysis, pyrolysis gases flow, sublimation of the charring layer and mechanical failure. The progressive loss of solid media and the inhomogeneous deformation of CFRPs are incorporated into the traditional ablation kinetic model, making it possible to describe the damage to CFRPs caused by both chemical reactions and thermal stress. The predicted damage morphology is consistent with the experimental results, revealing the generation of internal defects due to the synergistic effects of interlaminar tensile stress and matrix pyrolysis. Additionally, the effects of charring layer sublimation, laser power and process time on damage responses are analyzed, and the real-time evolution of damage degree is investigated.高能激光因其加工精度高、质量好而被广泛应用于碳纤维增强聚合物(CFRP)复合材料。然而，cfrp在加工过程中受到高能激光损伤的机理尚不清楚。本文对激光烧蚀cfrp的耦合机理进行了实验和理论研究。通过计算机断层扫描(CT)捕获激光损伤CFRPs的三维形态，定量表征热解炭化和内部分层的程度。在此基础上，建立了考虑基体热解、热解气体流动、炭化层升华和机械破坏的热-机-化耦合模型。传统的烧蚀动力学模型将固体介质的逐渐损失和cfrp的不均匀变形纳入烧蚀动力学模型，从而可以同时描述化学反应和热应力对cfrp的损伤。预测的损伤形态与实验结果一致，揭示了层间拉应力和基体热解协同作用下内部缺陷的产生。分析了炭化层升华、激光功率和工艺时间对损伤响应的影响，并研究了损伤程度的实时演变。Effect of atomic oxygen and vacuum thermal aging on graphene and glass fibre reinforced cyanate ester-based shape memory polymer composite for deployable thin wall structures.Sandaruwan Jayalath, Eduardo Trifoni, Jayantha Epaarachchi, Madhubhashitha Herath, Eleftherios E. Gdoutos, Bandu Samarasekaradoi:10.1016/j.compscitech.2024.110870 原子氧和真空热老化对石墨烯和玻璃纤维增强氰酸酯基形状记忆聚合物复合材料可展开薄壁结构的影响。Deployable components and structures are a crucial part of space exploration. Due to fewer parts, low weight and cost, shape memory polymers (SMPs) and their composites (SMPCs) are considered ideal candidates for this. However, lower thermal stability and poor durability in the space environment have limited their applicability. This research work details the development of Graphene Nanoplatelets (GNP) filled Glass Fibre (GF) reinforced cyanate ester-based SMPC with 0/90° and ±45° sandwich fibre lay-up configuration capable of multidirectional shape programming. The SMP matrix was synthesised by mixing Cyanate Ester and Polyethylene Glycol (PEG) with added GNP. SMPC was fabricated by pouring the SMP mixture into a pre-prepared glass mould with the added GF layers. The synthesised SMPC showed shape programming and recovery at 169.01±0.62°C and stable thermomechanical properties at the temperature of 130°C. Durability tests at extreme environmental conditions including Atomic Oxygen exposure, thermal vacuum aging, and elevated-temperature behaviour tests were conducted as these tests evaluate the durability and applicability of the SMPC for use in Earth’s orbits and lunar environments. The performances of the samples before and after durability tests were measured through mechanical tests, shape memory effect tests and a series of characterisation methods such as microscopic image analysis, FTIR and dynamic mechanical analysis. According to the results, AO exposure affected the SMPCs by eroding their surface. There were no changes in the chemical structure of the SMPC yet the thermomechanical, mechanical and shape memory properties were decreased without compromising their safe operational levels such as storage onset temperatures (128.79±3.08°C), maximum tensile stress (114.99±21.52 MPa), shape fixity (100%) and recovery ratios (100%). The erosion resistance of the GNP-filled SMPCs was improved with ∼54.35% less erosion than the SMPC without GNP. The vacuum thermal aging slightly slowed shape recovery from 31.17% to 8.32% at 160°C due to PEG crosslink degradation, however, 100% shape recovery was achieved at the end. Further durability tests under cryogenic temperatures and effects after vacuum thermal cycles are warranted to observe the synergistic effect on the SMPC for future developments. Exploring the scalability and additive manufacturability of the developed SMPC can be advantageous in the future while mitigating challenges such as complex shape programming, long-term materials degradation, resource efficiency and compliance with safety standards.可展开部件和结构是空间探索的重要组成部分。由于零件少、重量轻、成本低，形状记忆聚合物(SMPs)及其复合材料(smpc)被认为是理想的候选材料。然而，其热稳定性较低，在空间环境中的耐久性较差，限制了其适用性。这项研究工作详细介绍了石墨烯纳米片(GNP)填充玻璃纤维(GF)增强氰酸酯基SMPC的开发，该SMPC具有0/90°和±45°夹层纤维铺设配置，能够进行多向形状编程。以氰酸酯和聚乙二醇(PEG)为原料，加入GNP合成SMP基质。将加入GF层的SMP混合物倒入预先准备好的玻璃模具中制备SMPC。合成的SMPC在169.01±0.62℃时表现出形状可编程和恢复，在130℃时表现出稳定的热力学性能。在极端环境条件下进行了耐久性测试，包括原子氧暴露、热真空老化和高温行为测试，这些测试评估了SMPC在地球轨道和月球环境中使用的耐久性和适用性。通过力学试验、形状记忆效应试验以及显微图像分析、FTIR、动态力学分析等一系列表征方法，对耐久性试验前后试样的性能进行了测定。结果表明，AO暴露对smpc的影响主要是对其表面的侵蚀。SMPC的化学结构没有发生变化，但其热力学、力学和形状记忆性能均有所下降，但不影响其安全运行水平，如储存起始温度(128.79±3.08℃)、最大拉伸应力(114.99±21.52 MPa)、形状固定性(100%)和回复率(100%)。填充GNP的SMPC的抗侵蚀能力比没有GNP的SMPC减少了54.35%。在160°C时，由于PEG交联降解，真空热老化使形状恢复从31.17%略微减慢到8.32%，但最终形状恢复达到100%。进一步的低温耐久性试验和真空热循环后的影响是有必要的，以观察对SMPC的协同效应，为未来的发展做准备。探索已开发的SMPC的可扩展性和增材制造性在未来将有利于减轻复杂形状编程、长期材料降解、资源效率和符合安全标准等挑战。来源：复合材料力学仿真Composites FEM