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
Composite Structures
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。
Composites Part A: Applied Science and Manufacturing
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.
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.
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.