今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
3D printing of FRP grid and bar reinforcement for reinforced concrete plates: Development and effectiveness
Jun-Jie Zeng, Zi-Tong Yan, Yuan-Yuan Jiang, Pei-Lin Li
doi:10.1016/j.compstruct.2024.117946
用于钢筋混凝土板的 FRP 网格和钢筋的 3D 打印:开发与效果
3D printed concrete has become increasing popular in research and industry communities, while it faces a lack of effective internal reinforcement. Fiber-reinforced polymer (FRP) reinforcement, which has been used widely as reinforcement for concrete structures, has also been adopted to enhance the performance of 3D printed concrete structures. However, conventional FRP manufacturing processes such as pultrusion does not allow on-site forming of the products, leading to difficulties in construction. This paper aims to solve the above issues by developing a novel form of 3D printed continuous fiber reinforced thermoplastic polymers (CFRTPs) reinforcement for 3D printed concrete structures. An experimental program on tensile behavior of 3D printed CFRTP bars and grids was conducted. Then the CFRTP reinforcement was used for 3D printed high-performance concrete to explore the effectiveness of the reinforcement. Twenty-two 3D printed concrete plates were tested to explore the effects of the loading direction and fabrication type on the flexural behavior of FRP reinforced high-performance concrete plates. Results show that the performance of the 3D printed HPC plates can be considerably enhanced owning to the FRP reinforcement and the CFRTP reinforcement are comparable to conventional FRP reinforcement with similar dimensions. This study identifies further research needs on CFRTP reinforcement for construction and will pave the way for studies on 3D printed reinforced concrete structures with both concrete and FRP reinforcement being printed simultaneously.
3D 打印混凝土在研究和工业界越来越受欢迎,但它却面临着缺乏有效内部加固的问题。纤维增强聚合物(FRP)加固材料已被广泛用作混凝土结构的加固材料,也被用于提高 3D 打印混凝土结构的性能。然而,拉挤等传统 FRP 制造工艺无法实现产品的现场成型,导致施工困难。本文旨在通过为 3D 打印混凝土结构开发一种新型的 3D 打印连续纤维增强热塑性聚合物(CFRTPs)加固形式来解决上述问题。本文对 3D 打印 CFRTP 钢筋和网格的拉伸行为进行了实验。然后,将 CFRTP 加固材料用于 3D 打印高性能混凝土,以探索加固材料的有效性。测试了 22 块 3D 打印混凝土板,以探索加载方向和制造类型对 FRP 加固高性能混凝土板抗弯行为的影响。结果表明,由于使用了玻璃钢加固材料,3D 打印高性能混凝土板的性能大大提高,而且 CFRTP 加固材料的性能与尺寸相似的传统玻璃钢加固材料相当。这项研究确定了建筑用 CFRTP 加固的进一步研究需求,并将为同时打印混凝土和 FRP 加固的 3D 打印钢筋混凝土结构的研究铺平道路。
From mixed to hydrodynamic regime in lubricated sliding of carbon fiber tows
Noël Brunetière, Kiran Bhantrakuppe Narayanappa, Olga Smerdova
doi:10.1016/j.compositesa.2024.108088
碳纤维丝束润滑滑动中从混合到流体力学机制的变化
Carbon fiber tows are used as reinforcement material in composite elements. To ensure mechanical integrity of the composite structure, it is important to ensure a good positioning of the carbon fibers in the mold during the manufacturing process. The positioning of the carbon fiber tows depends greatly on the friction with the mold. In the present paper, the friction between a carbon tow placed on a cylindrical pin rubbing against a rotating glass disk is experimentally studied in both dry and resin-lubricated conditions on a dedicated tribometer. The tests are performed for different loading levels and sliding speeds. The results are compared to numerical simulations taking into account contact mechanics and lubrication. The tows are modeled using a simple elastic foundation approach coupled with the Reynolds equation when the resin flow is considered. It appears that the impact of the deformability of the tow on its frictional behaviour is significant. It conditions the transition between mixed and hydrodynamic lubrication regimes.
碳纤维丝束在复合材料中用作加固材料。为了确保复合材料结构的机械完整性,在制造过程中必须确保碳纤维在模具中的良好定位。碳纤维丝束的定位在很大程度上取决于与模具的摩擦力。本文在专用摩擦磨损试验机上,对置于圆柱销上的碳纤维丝束与旋转玻璃盘在干燥和树脂润滑条件下的摩擦情况进行了实验研究。试验针对不同的负载水平和滑动速度进行。试验结果与考虑了接触力学和润滑的数值模拟结果进行了比较。在考虑树脂流动时,使用简单的弹性基础方法和雷诺方程对拖曳进行建模。结果表明,丝束的变形能力对其摩擦行为的影响很大。它是混合润滑和流体动力润滑状态之间过渡的条件。
Synthesis of conducting polymer intercalated sodium vanadate nanofiber composites as active materials for aqueous zinc-ion batteries and NH3 gas sensors at room temperature
Se Hun Lee, Juyeon Han, Ok Sung Jeon, Yongyeol Park, Dongpyo Hong, Ali Mirzaei, Jichang Kim, Min Kyoon Shin, Young Joon Yoo, Myung Sik Choi, Jeeyoung Yoo, Sang Yoon Park
doi:10.1016/j.compositesb.2024.111305
在室温下合成导电聚合物插层钒酸钠纳米纤维复合材料,作为锌离子水电池和 NH3 气体传感器的活性材料
Among the key technologies required for building industrial safety systems is portable integrated safety devices based on gas sensors and rechargeable batteries. In preparation for such integrated devices, this study focuses on the synthesis of sodium vanadate nanofibers (SVNF) and poly(3,4-ethylene dioxythiophene) (PEDOT) intercalated SVNF (E-SVNF) composites by a simple sonochemical approach for room temperature NH3 gas sensing and zinc ion battery (ZIB) studies. Applying E-SVNF to ZIBs resulted in superior rate capability, with a capacity of 192.13 mAh g−1 at 15 A g−1. Furthermore, they demonstrated long-term cycling stability, maintaining 83.47% of their capacity at 15 A g−1 even after 3,000 cycles. The gas sensor incorporating E-SVNF showcased a high response and excellent selectivity, even at room temperature, with response values of 1.059 for 10 ppm and 1.113 for 70 ppm of NH3 gas. These remarkable enhancements in the electrochemical performance of ZIBs and the gas sensor are attributed to the insertion of conductive polymers between SVNF layers. This resulted in improved electrical conductivity, increased interlayer distance in the vanadate nanofiber structure, enhanced layered structural stability, increased oxygen vacancies, a decreased work function, and the formation of p-p heterojunctions, all of which contribute to improved functionality of the composites materials. This research is expected to serve as a cornerstone for the development of industrial safety systems.
建立工业安全系统所需的关键技术之一是基于气体传感器和可充电电池的便携式集成安全装置。为了给此类集成设备做准备,本研究重点关注通过简单的声化学方法合成钒酸钠纳米纤维(SVNF)和聚(3,4-乙烯二氧噻吩)(PEDOT)插层 SVNF(E-SVNF)复合材料,用于室温 NH3 气体传感和锌离子电池(ZIB)研究。将 E-SVNF 应用于锌离子电池 (ZIB) 可获得卓越的速率能力,在 15 A g-1 的条件下,容量为 192.13 mAh g-1。此外,它们还表现出了长期循环稳定性,在 15 A g-1 循环后仍能保持 83.47% 的容量。即使在室温下,含有 E-SVNF 的气体传感器也具有高响应和出色的选择性,对 10 ppm 和 70 ppm 的 NH3 气体的响应值分别为 1.059 和 1.113。ZIBs 和气体传感器电化学性能的显著提高归功于在 SVNF 层之间插入了导电聚合物。这提高了导电性,增加了钒酸盐纳米纤维结构中的层间距离,增强了层状结构的稳定性,增加了氧空位,降低了功函数,并形成了 p-p 异质结,所有这些都有助于提高复合材料的功能。这项研究有望成为开发工业安全系统的基石。
4D printed bio-inspired mesh composite materials with high stretchability and reconfigurability
Chengjun Zeng, Liwu Liu, Xiaozhou Xin, Wei Zhao, Cheng Lin, Yanju Liu, Jinsong Leng
doi:10.1016/j.compscitech.2024.110503
具有高拉伸性和可重构性的 4D 打印生物启发网状复合材料
Strain engineering such as Kirigami design offers viable solutions for transforming rigid or even non-stretchable materials into highly stretchable structures, thus providing new opportunities for building flexible electronic devices with biological tissue-like mechanical properties. However, the stretchability of stretchable structures based on traditional Kirigami design strategies often relies on out-of-plane deformation, thus posing a great challenge for flexible electronic devices with high planarity requirements. Moreover, the low modulus properties of conventional soft materials also put forward new requirements for flexible electronic devices with complex mechanical environment adaptability. Here, Kirigami-like mesh composite materials (MCMs) based on shape memory polymer (SMP) and continuous carbon fibers, inspired by the laminar layout pattern of biological collagen tissues, were proposed and fabricated by 4D printing. 4D printed MCMs achieve elongation only through in-plane deformation and can combine excellent mechanical properties with high stretchability. The customizable fiber orientation enables MCMs with tunable stretchability from 1.8% to 375% and tensile modulus spanning four orders of magnitude from 0.04 MPa to 1375 MPa. In addition, owing to the variable stiffness properties and shape memory effect of SMP, it is also possible to achieve tunable stretchability and mechanical properties of MCMs with predetermined fiber orientation by controlling the ambient temperature, which facilitates the design of flexible electronic devices that conform to complex thermodynamic environments.
应变工程(如 "剪纸"设计)为将刚性甚至不可拉伸的材料转化为高度可拉伸的结构提供了可行的解决方案,从而为制造具有类似生物组织机械特性的柔性电子设备提供了新的机遇。然而,基于传统 ""剪纸"设计策略的可拉伸结构的可拉伸性往往依赖于平面外变形,因此对平面度要求较高的柔性电子器件构成了巨大挑战。此外,传统软材料的低模量特性也对具有复杂机械环境适应性的柔性电子器件提出了新的要求。受生物胶原组织层状布局模式的启发,本文提出了基于形状记忆聚合物(SMP)和连续碳纤维的类桐木网状复合材料(MCM),并利用 4D 打印技术进行了制造。4D 打印 MCM 仅通过面内变形实现伸长,可兼具优异的机械性能和高拉伸性。可定制的纤维取向使 MCM 具有 1.8% 至 375% 的可调拉伸性,以及从 0.04 兆帕到 1375 兆帕的四个数量级的拉伸模量。此外,由于 SMP 具有可变刚度特性和形状记忆效应,因此还可以通过控制环境温度来实现具有预定纤维取向的 MCM 的可调拉伸性和机械特性,从而有助于设计符合复杂热力学环境的柔性电子器件。