今日更新：Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 3 篇，Composites Science and Technology 1 篇
Composites Part A: Applied Science and Manufacturing
Stochastic modelling of out-of-autoclave epoxy composite cure cycles under uncertainty
Molly Hall, Xuesen Zeng, Tristan Shelley, Peter Schubel
doi:10.1016/j.compositesa.2024.108110
不确定情况下高压釜外环氧树脂复合材料固化周期的随机建模
Thermoset polymers and composites are subject to several sources of uncertainty which can produce a range of cure outcomes. Recent research into stochastically modelled thermoset cure has indicated that accounting for raw material and process uncertainty can model this range of expected output parameters. However, the uncertainty quantification methods are highly test-intensive, and the results of the simulations have been validated with limited experimental data. This study proposes a simple approach to cure kinetics uncertainty quantification that can be applied to any cure kinetics model without the need for additional testing. Stochastic cure kinetics and temperature conditions for a popular out-of-autoclave carbon fibre/epoxy prepreg were used to produce output distribution functions for key cure events, and the results were validated using data from ten cure replicates. The quantified variation expected from the cure of this prepreg resulted in processing recommendations to ensure quality metrics are met during processing.
Strain-rate dependent mixed-mode traction laws for glass fiber-epoxy interphase using molecular dynamics simulations
Sanjib C. Chowdhury, John W. Gillespie
doi:10.1016/j.compositesb.2024.111351
利用分子动力学模拟玻璃纤维-环氧树脂间相的应变速率相关混合模式牵引定律
In this paper, we establish a methodology to predict strain rate-dependent mixed-mode traction-separation responses (i.e., traction laws) for glass-epoxy composite interphase using molecular dynamics (MD) simulations. Glass-epoxy interphases with monolayer glycidoxypropyltrimethoxy silane are prepared by varying silane number density from 0.0 nm−2 to 3.9 nm−2 following the epoxy-amine diffusion and curing reactions. To established the effects of strain rate and mode-mixity on the interphase traction laws, the nano-meter size interphase domain is loaded in various mode-mixity (θ = 0° (Mode−II), 15°, 30°, 45°, 60°, and 90° (Mode−I)) with full range of strain rates from quasit-static to high strain rate (∼1e16/s) where a theoretical plateau strength limit is predicted. Following our previous work on Mode-I [Chowdhury et al., Composites Part B 237 (2022) 109877], mathematical model is developed for Mode-II as function of strain rate for different interphase structures (i.e., silane number density). The continuum equivalent bi-linear cohesive traction law is developed using the MD results to determine the mode-mixity quadratic functions and associated exponents for peak tractions, energy absorption, crack initiation and crack opening displacement from the mixed-mode simulations data. The MD predicted traction laws can be used to model interphase in micromechanics finite element analysis to bridge the length scale for the prediction of fiber-matrix debonding in composites.
在本文中，我们建立了一种方法，利用分子动力学（MD）模拟来预测玻璃-环氧复合材料相间的应变速率依赖性混合模式牵引分离响应（即牵引定律）。在环氧胺扩散和固化反应之后，通过改变硅烷数量密度（从 0.0 nm-2 到 3.9 nm-2），制备了具有单层缩水甘油氧丙基三甲氧基硅烷的玻璃-环氧中间相。为了确定应变速率和模式混合度对相间牵引力规律的影响，在不同的模式混合度（θ = 0° (Mode-II)、15°、30°、45°、60°和 90° (Mode-I)）和从准静态到高应变速率（∼1e16/s）的全范围应变速率下加载了纳米级相间域，并预测了理论上的高原强度极限。根据我们之前关于模式 I 的研究成果[Chowdhury 等人，Composites Part B 237 (2022) 109877]，针对不同的相间结构（即硅烷数量密度），建立了模式 II 的数学模型，并将其作为应变速率的函数。利用 MD 结果开发了连续等效双线性内聚牵引定律，以从混合模式模拟数据中确定模式-混合二次函数以及峰值牵引、能量吸收、裂纹起始和裂纹张开位移的相关指数。MD 预测的牵引定律可用于在微观力学有限元分析中建立相间模型，从而弥合复合材料中纤维-基体脱粘预测的长度尺度。
Abundant nucleation sites-available liquid crystal hydrogel mimics bone ECM mineralization to boost osteogenesis
Lin Li, Kun Liu, Yating Lin, Wei Wen, Shan Ding, Mingxian Liu, Changren Zhou, Binghong Luo
doi:10.1016/j.compositesb.2024.111340
丰富的成核点--可用液晶水凝胶模拟骨 ECM 矿化，促进骨生成
Bone extracellular matrix (ECM) is a unique organic-inorganic composite material derived from highly mineralized liquid crystal (LC) organic substrate. However, it remains a substantial challenge to design bone ECM-like LC materials with sufficient available nucleation sites to mimic the mineralization process of natural bone. Herein, we designed a bioinspired hydrogel with bone ECM-like LC organic substrate and inorganic phosphate mineralization nucleation sites for robust cell biomineralization and bone regeneration. Black phosphorus (BP) nanosheet was firstly loaded by bioactive layered double hydroxide (LDH) based on electrostatic attraction to improve the stability and photothermal performance of BP. Then, the LDH@BP was creatively added into chitin whisker/poly (ethylene glycol) diacrylate (CHW/PEGDA) LC hydrogel, abbreviated as LCgel, to fabricate LCgel/LDH@BP to highly mimic the mineralization microenvironment of bone ECM. The bone ECM-like LC topology of LCgel/LDH@BP is conducive to facilitating cell adhesion, proliferation and osteogenic differentiation. More importantly, the in-situ phosphate mineralization nucleation sites combined with mild hyperthermia induced by BP can further synergistically reinforce biomineralization of cells adhered on bone ECM-like LC substrate, thus substantially promoting cell biomineralization-mediated osteogenesis in vitro and in vivo. This study opens a new insight for the design of bioinspired hydrogel for cell biomineralization-mediated osteogenesis.
Enhancing mechanical performance and high-temperature lubrication enabled by MoS2/WB2 nanolayered films
Zhenrong Gao, Weiming Nie, Haixin Wang, Siming Ren, Dali Du, ShiYu Du, Jinlong Li
doi:10.1016/j.compositesb.2024.111350
利用 MoS2/WB2 纳米层薄膜提高机械性能和高温润滑性能
Molybdenum disulfide (MoS2) films are widespread application in aerospace, nuclear, mechanical, and electronic fields owing to their unique structural characteristics and inherent interlayer slip. However, their utility is hindered by environmental susceptibility, particularly oxidation at elevated temperatures and in humid environments, limiting their effectiveness. Herein, we report a nanocomposite integrating MoS2 with WB2 by periodic alternating arrangement, synthesized using magnetron sputtering technology. This nanolayered architecture effectively harnesses the synergistic properties of both materials, imparting exceptional mechanical properties, superior environmental adaptability and efficient high-temperature lubrication. Methodical experiments and atomistic simulations reveal the incorporation of WB2 promotes preferential growth of MoS2 along the (002) plane, yielding an impressive hardness-to-elastic modulus ratio of approximately 0.10. The resultant films demonstrate notable achievements: a minimal friction coefficient of 0.056 and a specific wear rate of 1.88 × 10−7 mm3 N−1 m−1 in humid air. These findings are primarily stem from the synergistic interaction between MoS2 and metal-oxide nanoparticles at the sliding interface. Remarkably, even at 400 °C, the engineered MoS2/WB2 nanocomposite achieves low friction and wear under high contact stress, outperforming conventional MoS2-based materials. This innovative design, complemented by insights into the high-temperature friction mechanism, holds promise for advancing the development of robust and high-temperature-resistant lubricants.
Nowadays, high-pressure sensors are broadly utilized in manufacturing and applications for ensuring safe production and preventing failures. However, present high-pressure sensors are mainly fabricated by high-strength metal and cement, which are too heavy or easy-corrosive to satisfy long-term usage. Polymer piezoresistive materials have great potential due to their stability and light weight, but achieving high strength and durability at the same time remains a serious challenge. In this work, a high-strength pressure sensor is fabricated by epoxy resin/carbon fiber (EP/CF) composite, where CF builds a conductive network as a reinforcing phase and EP provides a durable and light-weight base phase. The conductive mechanism based on stress-induced structure has been elucidated, and the performance of related sensors in various conditions is revealed. The lightweight(∼1.28 g/cm3) pressure sensor manifests a wide sensing response range from 22 kPa to 80 MPa. Moreover, the durability of this novel pressure sensor is verified by repeating loading and unloading at a high pressure of 10 MPa for more than 3500 cycles. Meanwhile, the high temperature and water resistance are furtherly confirmed, where EP/CF composites exhibits excellent cycling stability (10 MPa, >1000 cycles) after heating (100 °C) or soaking in water. Attributed to the comprehensive performance of high-strength, ultrawide detection range, durability and light weight, EP/CF composites are applied for road safety monitoring and deep-sea operation, showing wide application prospects in high-pressure monitoring field.
