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 2 篇
Peridynamics for the fracture study on multi-layer graphene sheets
Xuefeng Liu, Zhiwu Bie, Peng Yu, Baojing Zheng, Xian Shi, Yong Fan, Xiaoqiao He, Chun Lu
doi:10.1016/j.compstruct.2024.117926
多层石墨烯薄片断裂的周动力学研究
Understanding the fracture properties of graphene sheets is a crucial step towards their practical applications. However, due to the limitations of experimental operations and all-atom (AA) methods, investigating the fracture of large-sized nano graphene sheets remains a formidable challenge. Especially, study on the layer-by-layer fracture of multi-layer graphene sheets (MLGS) is nearly impossible. To overcome this challenge, a peridynamic (PD) model is proposed in this study, which comprises the intra-layer part and the inter-layer part. The proposed PD model is validated by comparing the fracture toughness and the fracture forms of MLGS with existing experiments. It is found that the uniaxial tensile stress-strain curve of pre-cracked MLGS is closely related to the number of graphene layers in MLGS. The fracture property of MLGS can be enhanced by increasing the number of graphene layers, reducing the pre-crack length and blunting the pre-crack tip. Notably, asynchronous crack propagation with independent path observed in MLGS is a unique mechanism for strengthening the fracture property, which is distinct from monolayer graphene sheet. In this work, the PD theory is extended for the first time to investigate the in-plane fracture of large-sized nano MLGS.
了解石墨烯片的断裂特性是其实际应用的关键一步。然而,由于实验操作和全原子(AA)方法的限制,研究大尺寸纳米石墨烯片的断裂仍然是一个艰巨的挑战。特别是对多层石墨烯片的逐层断裂进行研究几乎是不可能的。为了克服这一挑战,本文提出了一种由层内部分和层间部分组成的周动力学(PD)模型。通过与现有实验对比MLGS的断裂韧性和断裂形式,验证了所提出的PD模型。研究发现,预裂MLGS的单轴拉伸应力-应变曲线与石墨烯层数密切相关。通过增加石墨烯层数、减小预裂纹长度和钝化预裂纹尖端,可以提高MLGS的断裂性能。值得注意的是,在MLGS中观察到的具有独立路径的异步裂纹扩展是一种独特的增强断裂性能的机制,这与单层石墨烯片不同。本文首次将PD理论扩展到研究大尺寸纳米MLGS的面内断裂。
Dual bionic-inspired stretchable strain sensor based on graphene/multi-walled carbon nanotubes/polymer composites for electronic skin
Weiqiang Hong, Xiaohui Guo, Tianxu Zhang, Xiaowen Zhu, Zhe Su, Yuan Meng, Yunong Zhao, Defeng Xu, Juncong Pan, Yinqi Huang, Hao Wang, Kai Xu, Hongyu Dong, Chenghao Zhang, Yanan Li, Xu Yan, Xingchen Huang
doi:10.1016/j.compositesa.2024.108043
基于石墨烯/多壁碳纳米管/聚合物复合材料的电子皮肤双仿生启发可拉伸应变传感器
With the rapid development of wearable electronic devices, stretchable strain sensors with wide strain range, high sensitivity, fast response, and high durability are urgently demanded. Here, a dual bionic-inspired stretchable strain sensor (DBSSS) with fingerprint patterns and biomimetic lotus root fiber structure is proposed. Silicone rubber (SR) is used as the encapsulation layer for the sensor, and multi-walled carbon nanotubes (MWCNT) are used as conductive bridges to connect graphene (GN) nanolaminates. The good cooperation of the two combined conductive materials with the fingerprint pattern structure significantly enhances the sensing function of DBSSS. DBSSS has high sensitivity (GF=35.33), wide strain sensing range (0–145%), fast response (∼80 ms), and good durability (>5000 cycles). Therefore, based on the excellent comprehensive performance of DBSSS, it can accurately realize gesture recognition, human micro-expression monitoring, and Morse code detection, which shows the broad application prospect of electronic skin.
随着可穿戴电子器件的快速发展,对应变范围宽、灵敏度高、响应速度快、耐久性高的可拉伸应变传感器提出了迫切的需求。本文提出了一种具有指纹图案和仿生莲藕纤维结构的双仿生可拉伸应变传感器(DBSSS)。硅橡胶(SR)被用作传感器的封装层,多壁碳纳米管(MWCNT)被用作连接石墨烯(GN)纳米层的导电桥。两种复合导电材料与指纹图案结构的良好配合,显著增强了DBSSS的传感功能。DBSSS具有高灵敏度(GF=35.33),宽应变传感范围(0-145%),快速响应(~ 80 ms)和良好的耐久性(>5000次循环)。因此,基于DBSSS优异的综合性能,能够准确实现手势识别、人体微表情监测、莫尔斯电码检测,显示出电子皮肤广阔的应用前景。
Enhanced interfacial property and thermal conductivity of pitch-based carbon fiber/epoxy composites via three-layer assembly of PDI/GN/PDI interphase
Xiaofeng Jiang, Chao Wang, Gang Li, Yunhua Yu, Xiaoping Yang
doi:10.1016/j.compositesb.2024.111238
通过PDI/GN/PDI界面相三层组装提高沥青基碳纤维/环氧复合材料的界面性能和导热性
Π-conjugate perylene diimide (PDI)/graphene (GN)/PDI interphase was designed and constructed on pitch-based carbon fiber (PCF) surface by multi-layer assembly, and the interfacial and thermal conductive performances of PCF/Epoxy (EP) composites with PDI, PDI/GN and PDI/GN/PDI interphase were investigated. Flat nanoscale structures with fragmented and wrinkled GN, PDI nanowires were respectively observed on PCF-GN, PCF-PDI/GN and PCF-PDI surface, while three-dimensional oblique cicada-wing nanostructure of three-layer interphase was constructed on PCF-PDI/GN/PDI surface due to the re-assembly of PDI under confinement constraint of GN substrate. Interlayer shear strength and transverse fiber bundle tensile strength of PCF-PDI/GN/PDI/EP composite were 28.4 %, 9.36 %, 12.0 % and 246 %, 85.8 %, 116 % higher than those of PCF-GN/EP, PCF-PDI/GN/EP and PCF-PDI/EP composites, which were attributed to the improvement of interface adhesion and the effectively buffer stress transfer between carbon fiber and resin matrix by introducing three-layer PDI/GN/PDI interphase. Additionally, PCF-PDI/GN/PDI/EP composites showed the highest heat conduction and thermal conductivity, ascribing to the construction of extra conductive paths and the weakening of phonons scattering from three-dimensional (3D) structure of PDI/GN/PDI interphase, which realized the formation of structure-function integration interphase of pitch-based carbon fiber composites.
通过多层组装在沥青基碳纤维(PCF)表面设计并构建了苝二酰亚胺(PDI)/石墨烯(GN)/PDI界面相Π-conjugate,研究了PDI、PDI/GN和PDI/GN/PDI界面相的PCF/环氧树脂(EP)复合材料的界面性能和导热性能。在PCF-GN、PCF-PDI/GN和PCF-PDI表面分别观察到碎片化和褶皱化的GN、PDI纳米线的扁平纳米结构,而在GN衬底约束下,PDI在PCF-PDI/GN/PDI表面进行了重新组装,形成了三层界面相的三维斜蝉翼纳米结构。PCF-PDI/GN/PDI/EP复合材料的层间抗剪强度和横向纤维束抗拉强度分别比PCF-GN/EP、PCF-PDI/GN/EP和PCF-PDI/EP复合材料分别提高28.4 %、9.36 %、12.0 %和246 %、85.8 %、116 %,这是由于引入三层PDI/GN/PDI界面相,提高了界面附着力,有效缓冲了碳纤维与树脂基体之间的应力传递。此外,PCF-PDI/GN/PDI/EP复合材料表现出最高的导热性和导热性,这是由于PDI/GN/PDI界面相的额外导电路径的构建和三维(3D)结构声子散射的减弱,实现了沥青基碳纤维复合材料结构-功能集成界面的形成。
Superior thermal transport and electrically insulating properties of epoxy composites with waxberry-like calcined alumina/poly diallyldimethylammonium chloride/diamond
Zhengdong Wang, Yuanhang Zhou, Meng Luo, Yumeng Zhang, Xiaolong Cao, Ziyan Zhang, Ran Wang, Xuefeng Zhang
doi:10.1016/j.compscitech.2024.110440
杨梅状煅烧氧化铝/聚二烯基二甲基氯化铵/金刚石环氧复合材料优越的热传递和电绝缘性能
This work reported a novel preparation of waxberry-like calcined alumina/poly diallyldimethylammonium chloride/diamond (AO*@ND) via a facile self-assembly of cationic polymer, electrostatic adsorption of nano-sized diamonds and calcination process. The incorporation of hybrid particles into an epoxy matrix significantly enhanced the thermal conductivity and dielectric properties. For example, the thermal conductivity of epoxy composite with 10 wt% calcined AO*@ND in air at 500 °C soars to a remarkable level of 0.70 W/(m·K) and 1.83 W/(m·K) at room temperature and 100 °C, respectively. In addition, its dielectric breakdown strength was 59.6 kV/mm, only showing a decrease of 11 % compared to that of epoxy. More importantly, the epoxy composites with the calcined AO*@ND showed an ultralow dielectric loss. The modification strategy of hybrid filler provides a new insight on the development of thermally conductive yet electrically insulating materials for future power modules and electrical equipment.
本文报道了一种通过阳离子聚合物的自组装、纳米金刚石的静电吸附和煅烧工艺制备杨梅状煅烧氧化铝/聚二烯基二甲基氯化铵/金刚石(AO*@ND)的新方法。将杂化颗粒掺入环氧树脂基体中,显著提高了其导热性和介电性能。例如,添加10 wt% AO*@ND的环氧复合材料在500℃空气中,室温和100℃时的导热系数分别达到0.70 W/(m·K)和1.83 W/(m·K)。此外,其介电击穿强度为59.6 kV/mm,仅比环氧树脂降低11%。更重要的是,经过煅烧的AO*@ND的环氧复合材料具有超低的介电损耗。混合填料的改性策略为未来电源模块和电气设备的导热绝缘材料的发展提供了新的思路。
Navigating the unknown: Tackling high-dimensional challenges in composite damage modeling with bootstrapping and Bayesian uncertainty quantification
Giuseppe Catalanotti
doi:10.1016/j.compscitech.2024.110462
导航未知:利用自举和贝叶斯不确定性量化解决复合材料损伤建模中的高维挑战
A methodology for quantifying uncertainty in high-dimensional problems involving sophisticated progressive damage models for composites is proposed. This approach combines bootstrapping and Bayesian Uncertainty Quantification to determine the distribution of Quantities of Interest typically related to structural response. Applied to a practical case involving a 40-dimensional problem with Open Hole Tension and Compression specimens, where stochastic variables include material and geometric parameters, as well as ply orientations, the methodology efficiently provides consistent predictions of QoI distributions. Its effectiveness makes it highly suitable for real industrial applications, enhancing capabilities in the design of composite structures.
提出了一种量化复合材料复杂渐进损伤模型高维问题不确定性的方法。这种方法结合了自举和贝叶斯不确定性量化来确定通常与结构响应相关的兴趣量的分布。将该方法应用于40维裸眼拉伸和压缩样品问题的实际案例,其中随机变量包括材料和几何参数以及层向,该方法有效地提供了qi分布的一致预测。它的有效性使其非常适合于实际工业应用,提高了复合材料结构设计的能力。