今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 3 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 2 篇
Composite Structures
Mechanical properties and failure behaviors of T1100/5405 composite T-joint under in-plane shear load coupled with initial defect and high-temperature
Li Guowei, Cao Ertai, Jia Ben, Zhang Xuanjia, Wang Wenzhi, Huang Heyuan
doi:10.1016/j.compstruct.2023.117722
T1100/5405 复合材料 T 型接头在平面剪切载荷、初始缺陷和高温作用下的力学性能和失效行为
The T1100/5405, a novel carbon fiber resin matrix composite, boasts superior specific strength, stiffness, and broad applicability. This study rigorously investigated the in-plane shear performance and thermally coupled damage failure mechanisms of this composite in a T-joint context under initial defects, being highly relevant for hypersonic vehicles in high-temperature environments. Experimental tests yielded mechanical property parameters and in-plane shear data for varying test temperatures (25℃, 150℃) and defect radius (0mm, 15mm). Compared to flawless samples at room temperature, the synergistic impact of high temperature and defects expedited the structural damage failure process, reducing load-bearing capabilities significantly. A numerical model was established based, on the inherent structural relationship of the cohesive zone model and the continuum damage mechanics of the composite, whose accuracy was confirmed by experimental data. Further analysis revealed that a high-temperature environment would exacerbate the damage failure process of initial defects. Specifically, as the temperature rose, the defect radius increased, thus diminishing the shear capacity of T-joint. The maximum structural ultimate load has been reduced by 67.54%, which was perfectly aligned with experimental results. Consequently, the study provides practical insights for the structural design of hypersonic vehicle composite.
T1100/5405 是一种新型碳纤维树脂基复合材料,具有优异的比强度、刚度和广泛的适用性。本研究严格研究了这种复合材料在初始缺陷条件下 T 型接头的面内剪切性能和热耦合损伤失效机制,这与高温环境下的高超音速飞行器高度相关。实验测试得出了不同测试温度(25℃、150℃)和缺陷半径(0 毫米、15 毫米)下的机械性能参数和平面剪切数据。与室温下的无缺陷样品相比,高温和缺陷的协同影响加速了结构的破坏过程,大大降低了承载能力。根据内聚区模型的固有结构关系和复合材料的连续损伤力学,建立了一个数值模型,其准确性得到了实验数据的证实。进一步的分析表明,高温环境会加剧初始缺陷的损坏失效过程。具体来说,随着温度的升高,缺陷半径增大,从而降低了 T 型接头的抗剪能力。最大结构极限载荷降低了 67.54%,与实验结果完全一致。因此,该研究为高超音速飞行器复合材料的结构设计提供了实用的启示。
Composites Part A: Applied Science and Manufacturing
Facile fabrication of low-content surface-assembled MXene in silicone rubber foam materials with lightweight, wide-temperature mechanical flexibility, improved flame resistance and exceptional smoke suppression
Chen Hai-Yang, Li Yang, Wang Peng-Huan, Qu Zhang-Hao, Qin Yu-Qing, Yang Ling, Li Jia-Yun, Gong Li-Xiu, Zhao Li, Zhang Guo-Dong, Gao Jie-Feng, Tang Long-Cheng
Silicone rubber foam (SiRF) is a promising porous material that is widely applied in various fields. However, its intrinsic flammability nature remains a significant challenge. One of the simplest and most economical solutions is to incorporate high content flame-retardant fillers. Unfortunately, such approach is limited by several drawbacks, including poor filler dispersion, difficulty in processing and negative effect on mechanical flexibility. Herein, we report a green and facile strategy for surface-assembling ultralow content of MXene sheets bonded onto the pore surface of SiRF via the effective foaming reaction process. The as-prepared MSiRF-0.2 composite at 0.2 wt% MXene exhibited lightweight characteristic, wide-temperature mechanical flexibility, UL94-V0 grade, limited oxygen index of >27%, and exceptional smoke suppression (reduction by 88.24%). Furthermore, flame-retardant mechanism was discussed based on the char structure observation. This study provides a novel approach for fabricating mechanically flexible and flame-retardant SiRF via in-situ reactive assembly of low content MXene sheets.
Triple-shape memory polybenzoxazine resins and their composites
Luo Lan, Niu Zhihong, Hu Rongxiang, Zhang Fenghua, Liu Yanju, Leng Jinsong
doi:10.1016/j.compositesa.2023.107910
三重形状记忆聚苯并恶嗪树脂及其复合材料
Shape memory polymer (SMP) as a new type of smart material can be programmed into a temporary shape by external excitation. Benzoxazine is a novel thermosetting resin with excellent heat resistance, high glass transition temperature (Tg) and mechanical properties. Here, triple-shape memory polybenzoxazines with high Tg were obtained by copolymerization of phenol/polyetheramine with phenol/furanamine benzoxazines. Electrically driven composites were prepared using multi-walled carbon nanotubes, and the SMP electrically driven function was achieved by forming a complete and continuous conductive permeable network inside the composites, shape recovery can be completed in 15 s at 60v. Furthermore, at high temperatures the carbon residue rate is increased to 45 % at 800 °C, demonstrating the high performance of electrically driven shape memory polymer composites. The realization of the triple and electrically induced shape memory properties of shape memory polybenzoxazines broadens the way for their application in extreme high-temperature environments in aerospace and aviation.
Flexible Multiwalled Carbon Nanotubes/cellulose nanofibers Membrane with Rapid Temperature Increasing Induced by Interface Strengthening
Chen Siyao, Chen Zhiyu, Ou Yangling, Lyu Junwei, Li Junning, Liu Xiangyang, Liu Yang
doi:10.1016/j.compositesa.2023.107911
通过界面强化快速升温的柔性多壁碳纳米管/纤维素纳米纤维膜
Towards advanced electrical heaters with superior Joule heating property, high electrical conductivity has always been critical issue. Herein, in addition to the commonly recognized factor of electrical conductivity, we proved that the composite interface poses significant effect on temperature increasing as electrical heaters. Specifically, direct fluorination utilizing F2/N2 was applied to selectively decorate the outer walls of multiwalled carbon nanotubes (MWCNTs) while keeping the inner tube intact, which was followed by compositing it with cellulose nanofibers (CNFs) to prepare F-MWCNTs/CNFs flexible membrane. Due to the enhanced electrostatic interaction at the interface and stronger phonon vibrational coupling, interfacial phonon diffusion was significantly improved, which facilitated a higher temperature increase rate in the F-MWCNTs/CNFs membrane compared to the unmodified MWCNTs/CNFs membrane when subjected to an electric field. This unique interfacial effect holds promise for the development of high-performance electrical heaters with rapid response.
Silicon carbide fiber manufacturing: Cost and technology
Yilmaz Sefa, Theodore Merlin, Ozcan Soydan
doi:10.1016/j.compositesb.2023.111101
碳化硅纤维制造:成本与技术
Significant advances have been made in the past decade concerning silicon carbide fiber manufacturing methods resulting in near-stoichiometric small-diameter fibers that meet the property requirements for most of the ceramic matrix composites (CMC) and nuclear applications. The manufacturing cost, however, remained prohibitively high, preventing the use of it in different applications requiring much lower cost. Silicon carbide (SiC) fiber reinforced CMC is dominated by the cost of SiC fiber which comprises more than 50 % of the finished part cost. This article provides insight into the SiC fiber manufacturing costs and highlights the need for an alternative SiC fiber precursor and manufacturing method. Analysis of the existing polycarbosilane (PCS)-based SiC fiber manufacturing shows that the crosslinking (curing) and raw material preparation steps are high-cost steps that need lower cost options. Alternative SiC fiber precursor should be sought for lowering the cost of SiC fibers.
Interlaminar shear strength of Carbon/PEEK thermoplastic composite laminate: Effects of in-situ consolidation by automated fiber placement and autoclave re-consolidation
Automated manufacturing techniques, such as Automated Fiber Placement (AFP), offer an opportunity over conventional manufacturing methods, such as autoclave curing, to save time and expenses. The present research focuses on evaluating the Interlaminar Shear Strength (ILSS) of Carbon/PEEK thermoplastic composite laminates manufactured by AFP in-situ consolidation and autoclave re-consolidation using the Short-Beam Shear (SBS) test. Additionally, a methodology is proposed to capture the differences observed in ILSS using a finite element simulation. In this respect, a thermoplastic laminate was fabricated using AFP in-situ consolidation. Baseline laminate was also produced by re-consolidating another AFP-made laminate inside the autoclave. A micrographic study was conducted to investigate the void content and fiber distribution resulting from each manufacturing process. The test results showed that the AFP technique results in an ILSS of the laminate that is 37 % lower than that of the autoclave-reconsolidated laminate. The distinct mechanical behaviour in the SBS test arising from in-situ consolidation and autoclave re-consolidation was differentiated in the finite element modeling utilizing cohesive elements. This distinction was achieved by numerically finding the proper interface strength properties based on the SBS experimental results. These interface properties serve as valuable input parameters for conducting further finite element modeling and analyses of Carbon/PEEK thermoplastic composite laminates manufactured by AFP in-situ consolidation.
Metal coordination in polymer drives efficient phonon transfer through self-assembled microstructures
Zheng Shuxin, Mu Liwen, Zhang Suoying, Lu Xiaohua, Zhu Jiahua
doi:10.1016/j.compscitech.2023.110348
聚合物中的金属配位通过自组装微结构驱动高效声子传递
Molecular interactions such as hydrogen bond, van der Waals force, covalent bond in association with heat transfer in polymeric materials have been reported, while the relationship between metal-polymer coordination and thermal conduction has not been studied yet. In this work, the molecularly-assembled microstructure of the composites produced by metal coordination with polyvinyl alcohol (PVA) reveals a qualitative correlation between microstructure and thermal conductivity (TC). The ellipsoid-shaped domain and increased coil size create stable phonon transmission channels, which are beneficial for boosting TC by lengthening the mean free path of phonon propagation. Strong coordination between the metal ions and the hydroxyl groups in the polyvinyl alcohol chains results in competition between the inter- and intra-molecular OH–OH hydrogen bonds, which eventually takes precedence. Such coordination structure creates distinctive micro-crystal domains and is discovered to be essential for TC enhancement. Moreover, the power generation value of thermal conversion using PVA-H/2.0Fe(NO3)3 film is twice that of pure PVA-H film, which has higher and faster conversion efficiency. These materials have been demonstrated as excellent candidates for improving the conversion efficiency of thermoelectric devices. In summary, this work offers a new strategy for regulating TC through metal coordination and a fundamental comprehension of the link between metal coordination, microstructure, and TC in polymer composites.
Tailoring the mechanical and combustion performance of B/HTPB composite solid fuel with covalent interfaces
Jiang Yue, Leem Juyoung, Robinson Ashley M., Wu Shuai, Huynh Andy H., Ka Dongwon, Zhao Ruike Renee, Xia Yan, Zheng Xiaolin
doi:10.1016/j.compscitech.2023.110350
利用共价界面定制 B/HTPB 复合固体燃料的机械和燃烧性能
The development of high-performing solid fuels with desired mechanical and combustion properties is critical to future air-breathing propulsion systems for space exploration and hypersonic navigation. Boron (B)/hydroxyl-terminated polybutadiene (HTPB) composite has been studied for this purpose due to the high energy density (heat of combustion) of B and the appropriate processability and mechanical properties of HTPB. However, the weak interface between B and HTPB results in weakened mechanical properties, agglomerated B particles, and slow and inefficient combustion, especially for composites with high B loading (30 wt% and above). In this study, the effect of interface between B and HTPB on the combustion and mechanical performance of high-loading B/HTPB composites was investigated by surface functionalization of B particles. Three interfacial characteristics were compared: polar (pristine B)/nonpolar (HTPB), nonpolar (hydrocarbon-functionalized B)/nonpolar (HTPB), and covalently bonded (amine-functionalized B/HTPB) interfaces. It was found that both covalently bonded and nonpolar/nonpolar interfaces effectively reduced the aggregation of B particles in the HTPB matrix, even with up to 45 wt% B loading, thus promoting the combustion efficiency and burning rate. Moreover, covalently bonded interfaces in B/HTPB composites led to strain-hardening behaviors, resulting in enhanced strength, ductility, and toughness. This work highlights the significance of interface engineering in B/HTPB composites for the efficacy and safety of future air-breathing solid-fueled propulsion devices.
开发具有理想机械和燃烧特性的高性能固体燃料对于未来用于太空探索和高超音速导航的喷气推进系统至关重要。硼(B)/羟基封端聚丁二烯(HTPB)复合材料因其硼的高能量密度(燃烧热)以及 HTPB 的适当加工性和机械性能而被用于这一目的的研究。然而,硼和 HTPB 之间的弱界面会导致机械性能减弱、硼颗粒团聚、燃烧缓慢且效率低下,尤其是在硼含量较高(30 wt% 及以上)的复合材料中。本研究通过对 B 颗粒进行表面官能化处理,研究了 B 与 HTPB 之间的界面对高负载 B/HTPB 复合材料燃烧和机械性能的影响。比较了三种界面特性:极性界面(原始 B)/非极性界面(HTPB)、非极性界面(烃官能化 B)/非极性界面(HTPB)和共价键界面(胺官能化 B/HTPB)。研究发现,共价键界面和非极性/非极性界面都能有效减少 B 粒子在 HTPB 基质中的聚集,即使 B 的负载量高达 45 wt%,也能有效减少 B 粒子的聚集,从而提高燃烧效率和燃烧速率。此外,B/HTPB 复合材料中的共价键界面导致了应变硬化行为,从而提高了强度、延展性和韧性。这项研究强调了 B/HTPB 复合材料界面工程对于未来喷气式固体燃料推进装置的有效性和安全性的重要意义。