【新文速递】2023年11月5日复合材料SCI期刊最新文章

今日更新：Composite Structures 5 篇，Composites Part A: Applied Science and Manufacturing 6 篇，Composites Science and Technology 1 篇

Composite Structures

Experimental and numerical optimization of variable stiffness tensile coupons with a hole for maximum stiffness

Wu Zhenbo, Zhao Tian, He Chunwang, Liao Haitao, Li Ying

doi:10.1016/j.compstruct.2023.117643

带孔最大刚度可变拉伸试样的实验和数值优化

Anisotropic stiffness properties of carbon fiber-reinforced polymer composites (CFRPCs) can be designed by arranging the fiber path. In this paper, we propose a novel method to optimize the fiber path using the genetic algorithms (GA) and simulated annealing algorithms (SAA) combined with the quasi-uniform cubic B-spline curves. The optimization goal is to obtain the largest reaction force of an open-hole plate under uniaxial tensile loading. After the finite element method (FEM) and experimental verifications, the optimized variable-stiffness specimen owes the higher strength and stiffness, compared with the unidirectional one. Besides, the stress concentration can be reduced. One of the key points of this paper is to use the GA and SAA to control the slight data points to optimize the B-spline curve. By reducing the number of optimization variables, the computational efficiency is improved greatly. Moreover, by increasing the interval variables of the B-spline curve, we further improve the accuracy of optimization results. The range of values for the control points can be easily adjusted according to the manufacturing and design requirements. We also compare the optimization results of GA and SAA. Both of them can get the similar optimization results, and the SAA has a better convergence speed and accuracy. The proposed optimization method can be extended for three-dimensional preform and structure design in the future.

碳纤维增强聚合物复合材料（CFRPC）的各向异性刚度特性可以通过安排纤维路径来设计。本文提出了一种利用遗传算法（GA）和模拟退火算法（SAA）结合准均匀立方 B-样条曲线优化纤维路径的新方法。优化目标是获得开孔板在单轴拉伸载荷下的最大反作用力。经过有限元法（FEM）和实验验证，与单向试样相比，优化后的变刚度试样具有更高的强度和刚度。此外，还能减少应力集中。本文的重点之一是利用 GA 和 SAA 控制微小数据点来优化 B-样条曲线。通过减少优化变量的数量，大大提高了计算效率。此外，通过增加 B-样条曲线的区间变量，我们进一步提高了优化结果的精度。控制点的取值范围可根据制造和设计要求轻松调整。我们还比较了 GA 和 SAA 的优化结果。两者都能得到相似的优化结果，而 SAA 的收敛速度和精度更高。所提出的优化方法将来可以扩展到三维预成型和结构设计中。

Deformation failure mechanism and constitutive model of gradient aluminum foam under impact loading

Liu Xiongfei, Wang Yanru, He Ximin, Liu Hanqing, Cao Shaojun

doi:10.1016/j.compstruct.2023.117684

冲击荷载下梯度铝泡沫的变形破坏机理和构成模型

The dynamic mechanical response and energy absorption characteristics of gradient aluminum foam under impact loading with strain rates of 150 s−1, 340 s−1, and 550 s−1 have been studied based on the Split Hopkinson Pressure Bar (SHPB) test in this paper. X-CT and numerical simulations were carried out to analyze the deformation of the micro-porous structure of gradient aluminum foam during impact compression. A constitutive model for gradient aluminum foam under impact load was further established. The results show that the mechanical properties of aluminum foam are positively correlated with the strain rate. The better energy absorption effect of gradient aluminum foams than the homogeneous aluminum foam under impact loading was confirmed. Negative gradient aluminum foam exhibited a 46.9 % higher specific energy absorption rate than homogeneous aluminum foam. The failure mode of homogeneous and positive gradient aluminum foam was observed to be 'from the proximal to the distal', whereas negative gradient aluminum foam exhibited a 'from the distal to the proximal' failure mode. The Sherwood-Frost model, considering the shape, density, and strain rate function correction, could accurately predict the impact stress–strain curve of gradient aluminum foam, which can be served as a reference for the optimal design of gradient aluminum foams.

本文基于分离式霍普金森压力棒（SHPB）试验，研究了梯度铝泡沫在应变速率为 150 s-1、340 s-1 和 550 s-1 的冲击载荷下的动态力学响应和能量吸收特性。通过 X-CT 和数值模拟分析了梯度铝泡沫在冲击压缩过程中的微孔结构变形。并进一步建立了梯度铝泡沫在冲击载荷下的构成模型。结果表明，泡沫铝的力学性能与应变速率呈正相关。在冲击载荷下，梯度铝泡沫比均质铝泡沫具有更好的能量吸收效果。负梯度铝泡沫的比能量吸收率比均质铝泡沫高 46.9%。据观察，均质铝泡沫和正梯度铝泡沫的失效模式是 "从近端到远端"，而负梯度铝泡沫的失效模式是 "从远端到近端"。舍伍德-弗罗斯特模型考虑了形状、密度和应变率函数修正，能准确预测梯度铝泡沫的冲击应力-应变曲线，可作为梯度铝泡沫优化设计的参考。

An investigation of Fatigue Behavior and Residual Strength Model of Steel-GFRP Composite Bar

Cai Yong-Jian, Xie Zhi-Hong, Xiao Shu-Hua, Huang Ze-Run, Lin Jia-Xiang, Guo Yong-Chang, Zhuo Ke-Xian, Huang Pei-yan

doi:10.1016/j.compstruct.2023.117685

钢-GFRP 复合材料棒的疲劳行为和残余强度模型研究

Steel-fiber reinforced polymer (FRP) composite bar (SFCB) combines the advantages of corrosion resistance of FRP and good ductility of steel, and is a promising reinforcement material to improve the service life of marine structures. However, the fatigue behavior of SFCB is complex and has not been explored. Therefore, in this study, fatigue tests were conducted at different stress levels (0.32, 0.36, and 0.41 of quasi-static tensile strength with a fixed stress ratio of 0.1) and tensile tests were performed after fatigue pre-damage for a certain number of cycles (25%, 50%, and 75% of the fatigue life) to investigate the fatigue behavior of SFCB. The results show that fatigue failure is caused by steel core fracture, and the FRP layer can improve the fatigue life. Compared with the change of residual strength, the stiffness degradation of SFCB during fatigue loading was not significant. Finally, a residual strength prediction model containing known parameters of the S-N curve is also proposed, which can well predict the residual strength decay of SFCB after fatigue damage. In conclusion, these findings and the proposed residual strength prediction model contribute to the understanding and design of SFCBs.

钢纤维增强聚合物（FRP）复合材料（SFCB）兼具 FRP 的耐腐蚀性和钢的良好延展性，是一种很有前途的增强材料，可提高海洋结构的使用寿命。然而，SFCB 的疲劳行为十分复杂，尚未得到深入研究。因此，本研究在不同应力水平（0.32、0.36 和 0.41 的准静态抗拉强度，固定应力比为 0.1）下进行了疲劳试验，并在疲劳预损伤后进行了一定循环次数（疲劳寿命的 25%、50% 和 75%）的拉伸试验，以研究 SFCB 的疲劳行为。结果表明，疲劳破坏是由钢芯断裂引起的，而玻璃钢层可以提高疲劳寿命。与残余强度的变化相比，SFCB 在疲劳加载期间的刚度退化并不显著。最后，还提出了一个包含 S-N 曲线已知参数的残余强度预测模型，该模型可以很好地预测 SFCB 在疲劳破坏后的残余强度衰减。总之，这些发现和提出的残余强度预测模型有助于理解和设计 SFCB。

Mechanistic modeling considering the bottom edge cutting effect and the material anisotropy during end milling of the aluminum honeycomb core

Li Chao, Duan Chunzheng, Tian Xiaodong, Wang Chao

doi:10.1016/j.compstruct.2023.117686

考虑铝蜂窝芯端面铣削过程中底边切削效应和材料各向异性的力学模型

In the end milling of aluminum honeycomb core, the bottom edge of the cutter and the feed direction of the cutter will have a significant impact on the surface machining quality. If the above two factors are neglected in mechanistic modeling, the surface machining quality will be difficult to improve. In this paper, a mechanistic model considering the bottom edge cutting effect and the anisotropic characteristics of the material is firstly proposed to accurately predict cutting forces. Based on the contact relationship between the bottom edge and the honeycomb wall, a cutting force model of the bottom edge is developed, which includes the geometric characteristics of the bottom edge and the thin-walled cutting angle. For anisotropic characteristics of the material, a dynamic variation model of the entry and exit angles in any cutting direction is established on the basis of the structural model of the honeycomb core and cutting edge trajectory. The proposed mechanistic model was validated through a series of milling experiments. The results indicate that this model can be used to predict the cutting force of various parts of the cutter (including bottom and flank edges) and any feed direction.

在铝蜂窝芯的端铣加工中，铣刀底刃和铣刀进给方向对表面加工质量有很大影响。如果在力学建模中忽略上述两个因素，表面加工质量将难以提高。本文首先提出了一种考虑底刃切削效应和材料各向异性特征的力学模型，以准确预测切削力。根据底边与蜂窝壁的接触关系，建立了底边切削力模型，其中包括底边的几何特征和薄壁切削角。针对材料的各向异性特征，在蜂窝芯结构模型和切削刃轨迹的基础上，建立了任意切削方向上进入角和退出角的动态变化模型。通过一系列铣削实验对所提出的力学模型进行了验证。结果表明，该模型可用于预测刀具各部分（包括底刃和侧刃）和任何进给方向的切削力。

Trans-scale dynamic shear-lag model for the impact performance of fiber-reinforced composites

Cong Chaonan, Liu Junjie, Yu Zhongliang, Wei Yueguang, Wei Xiaoding

doi:10.1016/j.compstruct.2023.117688

纤维增强复合材料冲击性能的跨尺度动态剪切滞后模型

This study proposes a new trans-scale dynamic shear-lag model that integrates the strain gradient linear viscoelasticity theory to investigate the effects of size and viscous softening on the dynamic mechanical properties and energy absorption characteristics of fiber-reinforced composites with micro- and nano-structures. The proposed model clarifies how the strain gradient effect can decrease energy dissipation in the matrix. Our investigation suggests that both classical and higher-order viscosities of the submicron-scale matrix can synergistically optimize energy dissipation. Furthermore, parametric studies demonstrate that the attenuation efficiency of absorbed energy changes non-monotonically with microstructure and constituent properties, such as matrix thickness, strain gradient elasticity parameter, classical viscosity, and high-order viscosity. The trans-scale dynamic shear-lag model advances our understanding of the energy dissipation in the submicron-scale viscoelastic matrix of fiber-reinforced composites and provides valuable guidance for developing composites with micro- and nano-structures that display exceptional dynamic properties.

本研究提出了一种新的跨尺度动态剪切滞后模型，该模型整合了应变梯度线性粘弹性理论，用于研究尺寸和粘性软化对具有微米和纳米结构的纤维增强复合材料的动态力学性能和能量吸收特性的影响。所提出的模型阐明了应变梯度效应如何降低基体中的能量耗散。我们的研究表明，亚微米尺度基体的经典粘度和高阶粘度可以协同优化能量耗散。此外，参数研究表明，吸收能量的衰减效率与微观结构和组成特性（如基体厚度、应变梯度弹性参数、经典粘度和高阶粘度）呈非单调变化。跨尺度动态剪切滞后模型加深了我们对纤维增强复合材料亚微米尺度粘弹性基体中能量耗散的理解，为开发具有微米和纳米结构的复合材料提供了宝贵的指导，使其显示出卓越的动态特性。

Composites Part A: Applied Science and Manufacturing

Suppression of compression induced delamination in tapered laminated composites using a ply scarfing method

Gordon Tharan, Wisnom Michael R., Chul Kim Byung

doi:10.1016/j.compositesa.2023.107870

使用层叠围巾法抑制锥形层压复合材料中的压缩诱导分层

Thickness tapering of composite laminates is a common strategy for efficient and lightweight composite structures. The termination of specific plies necessary to achieve such tapering is well known to introduce sites for delamination initiation in laminates. This propensity for delamination is highly dependent on the thickness of the terminated ply, which presents a significant challenge in using thicker materials to improve the production rate of large-scale composite structures. In this work, the effectiveness of ply scarfing in improving the compressive failure stress of tapered laminates made using thick, unidirectional non-crimp fabrics (NCF) was experimentally investigated for the first time. Unidirectional tapered laminates were manufactured using two different NCFs with fibre areal weights of 620 and 1070 g/m2 via resin infusion. Specimens made of the 1070 g/m2 material which incorporated a ply terminated using the ply scarfing method were compared with those including plies terminated using the conventional ply-drop method. which incorporated a ply terminated using the ply scarfing method. The compression failure behaviour of the specimens was analysed using a high-speed camera. The results showed that ply scarfing suppressed delamination of the belt plies under compression and increased the failure stress by ∼60%. Furthermore, the tapered geometry of the terminated ply’s end was effective in preventing the void entrapment at the ply drop and significantly reducing the manufacturing variability.

复合材料层压板的厚度渐变是实现高效轻质复合材料结构的常用策略。众所周知，为实现这种锥形结构而必须终止特定的层板，从而在层板中引入分层起始点。这种分层倾向在很大程度上取决于终止层的厚度，这对使用更厚的材料来提高大规模复合材料结构的生产率提出了巨大挑战。在这项工作中，我们首次通过实验研究了使用厚的单向非卷曲织物（NCF）制作的锥形层压板在改善压缩破坏应力方面的效果。单向锥形层压板是使用两种不同的 NCF 通过树脂灌注制造的，纤维平均重量分别为 620 克/平方米和 1070 克/平方米。用 1070 克/平方米的材料制成的试样与用传统的层叠方法制成的试样进行了比较，前者包含了用层叠围巾法终止的层叠，后者包含了用层叠围巾法终止的层叠。使用高速照相机分析了试样的压缩破坏行为。结果表明，褶皱法抑制了带层在压缩条件下的分层，并将破坏应力提高了 60%。此外，终止层末端的锥形几何形状可有效防止层落处的空隙裹挟，并显著降低 制造变异性。

Development of a spread-tow fabric composite bipolar plate with fiber-spreading effect for vanadium redox flow battery

Choe Jaeheon, Lee Dongyoung, Yoon On Seung, Su Kim Seong, Woo Lim Jun

doi:10.1016/j.compositesa.2023.107878

开发用于钒氧化还原液流电池的具有纤维铺展效应的铺展式织物复合双极板

This study investigates a spread-tow fabric carbon/epoxy composite as an alternative to graphite bipolar plates in vanadium redox flow batteries. A spread-tow fabric composite can leverage the electrical and mechanical properties of conventional unidirectional and densely woven fabrics. Spread-tows can reduce the morphological effect of fiber tows on both properties by minimizing the height variation in the fabric and the generation of crimps, referred to as the fiber-spreading effect. The developed spread-tow carbon/epoxy composite bipolar plate with a 10k spread-tow exhibited an area-specific resistance similar to that of a unidirectional fabric and lower than that of conventional 1k and 3k woven fabric composites. Furthermore, the tensile strength reached 762 MPa, approximately 85% higher than that of the unidirectional fabric composite. The spread-tow bipolar plate specimen demonstrated gas tightness for 100 h and achieved an energy efficiency of 81.18% without any damage or degradation during single-cell charge/discharge tests.

本研究探讨了在钒氧化还原液流电池中，将铺展式碳/环氧织物复合材料作为石墨双极板的替代品。展丝织物复合材料可充分利用传统单向密织织物的电气和机械特性。通过最大限度地减少织物的高度变化和卷边（即纤维蔓延效应）的产生，展丝可减少纤维束对这两种特性的形态影响。所开发的展丝碳/环氧复合材料双极板具有 10k 展丝，其特定区域阻力与单向织物相似，低于传统的 1k 和 3k 编织物复合材料。此外，拉伸强度达到 762 兆帕，比单向织物复合材料高出约 85%。在单电池充放电测试中，展拖双极板试样在 100 小时内表现出气密性，能量效率达到 81.18%，且无任何损坏或退化。

MXene/Cellulose Composites as Electromagnetic Interference Shields: Relationships between Microstructural Design and Shielding Performance

Aghvami-Panah Mohammad, Ameli Amir

doi:10.1016/j.compositesa.2023.107879

作为电磁干扰屏蔽材料的 MXene/纤维素复合材料：微结构设计与屏蔽性能之间的关系

High performance and sustainable shielding materials are in great demand to mitigate electromagnetic interference (EMI) pollution. MXene/polymer composites have emerged as highly efficient EMI shields. Cellulose as a naturally occurring polymer has garnered a great deal of attention owing to its sustainability, abundance, and desirable mechanical properties. Therefore, MXene/cellulose composites have become attractive EMI solutions with outstanding effectiveness. Micro/nano-structural design plays a key role for the shielding performance and mechanisms. This paper aims to outline recent advances in MXenes/cellulose EMI shields and provide a deep understanding of the structure-performance relationships in both solid and porous shields. After discussing the shielding mechanisms, the role of hybrid material composition, interactions, interfaces, morphology, and fabrication methods on the shielding efficiency and mechanisms are scrutinized. Overall, solid composite films exhibit reflection dominant shielding mechanism, while porous materials and complex microstructures can be designed for enhanced absorption. Finally, the challenges hindering the widespread adoption of MXene/cellulose shields are highlighted and their future horizons are unveiled.

在减轻电磁干扰（EMI）污染方面，对高性能和可持续屏蔽材料的需求量很大。MXene/聚合物复合材料已成为高效的电磁干扰屏蔽材料。纤维素作为一种天然聚合物，因其可持续性、丰富性和理想的机械性能而备受关注。因此，MXene/纤维素复合材料已成为极具吸引力的 EMI 解决方案，而且效果显著。微/纳米结构设计对屏蔽性能和机制起着关键作用。本文旨在概述 MX 烯/纤维素 EMI 屏蔽的最新进展，并深入了解固体和多孔屏蔽的结构-性能关系。在讨论了屏蔽机理之后，还仔细研究了混合材料的成分、相互作用、界面、形态和制造方法对屏蔽效率和机理的作用。总体而言，固体复合薄膜的屏蔽机制以反射为主，而多孔材料和复杂微结构的设计可以增强吸收。最后，强调了阻碍 MXene/纤维素屏蔽广泛应用的挑战，并揭示了其未来前景。

Real-time evaluating temperature-dependent interfacial shear strength of thermoplastic composites based on interfacial stress impedance effect of magnetic fibers

Li Yunlong, Feng Tangfeng, Wang Yunfei, Zhu Zihao, Peng Hua-Xin, Xu Peng, Qin Faxiang

doi:10.1016/j.compositesa.2023.107874

基于磁性纤维界面应力阻抗效应实时评估热塑性复合材料随温度变化的界面剪切强度

Thermoplastic composites are susceptible to service environments. Precise evaluation of temperature-dependent interfacial shear strength (IFSS) is essential for determining and predicting mechanical properties and service life. However, great challenge exists in the measurement of temperature-dependent IFSS by micromechanical tests, due to polymer deformation at elevated temperatures. Here, we report a novel prediction methodology based on the interfacial stress impedance effect of magnetic fibers (MFs) for non-destructive and real-time evaluation of temperature-dependent IFSS. The MFs are optimized by annealing and surface modification to obtain a linear relationship between the impedance properties of MF and radial compressive stresses. Through the impedance measurement and corresponding IFSS micromechanical test, a correlation model between the IFSS of composite and impedance of MF is established. The IFSS at elevated temperatures calculated by this model is consistent with the results of micromechanical tested by up to 95 %, and allows for evaluating the IFSS of composites beyond the glass transition point. The prediction methodology utilizing MF features merits of convenient operation from the impedance measurement as well as high reliability and wide operating temperature from the nonmechanical nondestructive test, paving a novel avenue to real-time evaluate temperature-dependent IFSS of advanced thermoplastic composites.

热塑性复合材料容易受到使用环境的影响。精确评估随温度变化的界面剪切强度（IFSS）对于确定和预测机械性能和使用寿命至关重要。然而，由于聚合物在高温下会发生变形，因此在通过微机械测试测量随温度变化的 IFSS 方面存在巨大挑战。在此，我们报告了一种基于磁性纤维（MF）界面应力阻抗效应的新型预测方法，用于无损和实时评估随温度变化的 IFSS。通过退火和表面改性对磁性纤维进行优化，以获得磁性纤维阻抗特性与径向压应力之间的线性关系。通过阻抗测量和相应的 IFSS 微机械测试，建立了复合材料的 IFSS 与 MF 阻抗之间的相关模型。该模型计算出的高温下的 IFSS 与微机械测试结果的一致性高达 95%，可用于评估玻璃化转变点之后复合材料的 IFSS。利用 MF 的预测方法具有阻抗测量操作方便、非机械无损测试可靠性高、工作温度范围广等优点，为实时评估先进热塑性复合材料随温度变化的 IFSS 铺设了一条新途径。

MOFs Decorated TA-MoS2 Nanosheets Improving the Mechanical and Fire Properties of Epoxy Resins: Interface Engineering Design Based on Virginia Creeper

Yin Lian, Shi Congling, Wang Changhao, Qiu Peiyun, Qian Xiaodong, Zhou Keqing

doi:10.1016/j.compositesa.2023.107876

MOFs Decorated TA-MoS2 Nanosheet Improving the Mechanical and Fire Properties of Epoxy Resins：基于弗吉尼亚爬山虎的界面工程设计

Developing high-performance polymers with outstanding fire safety and mechanical performance remains a thorny challenge. Hence, inspired by Virginia creepers, an interface engineering design was used to load NH2-MIL-Fe onto the surface of tannic acid (TA)-modified molybdenum disulfide (MoS2), gestating TA-MoS2-NMFe nanohybrids with biomimetic structure. The TA-MoS2-NMFe exhibited well dispersion and interfacial compatibility in the epoxy resin (EP) matrix, which facilitated the improvement of the EP nanocomposites properties. Subsequently, the EP/TA-MoS2-NMFe nanocomposites showed a creeper sucker structure that could withstand high external force, resulting in growths of 49.9% in tensile strength and 67.3% in elongation at break. Moreover, the incorporation of TA-MoS2-NMFe decreased the maximum thermal degradation rate from 1.35%/℃ to 1.0%/℃, leading to EP nanocomposites with excellent thermal stability. Likewise, compared to pure EP, EP/TA-MoS2-NMFe achieved reductions of 42.3%, 41.2%, 50.8% and 71.1% in the peak heat release rate, total heat release, peak smoke production rate and smoke factor, respectively, which was better than reported works. It was due to the catalytic carbon formation of metal ions, the expansion charring characteristics of TA, barrier effect of MoS2 and dilution effect of nonflammable gases. Briefly, this work provides an innovative way to developing high-performance polymers from a bionic perspective.

开发具有出色防火安全性和机械性能的高性能聚合物仍然是一项棘手的挑战。因此，受弗吉尼亚州爬山虎的启发，我们利用界面工程设计将 NH2-MIL-Fe 添加到单宁酸（TA）修饰的二硫化钼（MoS2）表面，孕育出具有仿生物结构的 TA-MoS2-NMFe 纳米杂化物。TA-MoS2-NMFe 在环氧树脂（EP）基体中表现出良好的分散性和界面相容性，这有助于改善 EP 纳米复合材料的性能。随后，EP/TA-MoS2-NMFe 纳米复合材料呈现出可承受高外力的爬行吸盘结构，使拉伸强度增长了 49.9%，断裂伸长率增长了 67.3%。此外，TA-MoS2-NMFe 的加入使最大热降解率从 1.35%/℃ 降至 1.0%/℃，从而使 EP 纳米复合材料具有优异的热稳定性。同样，与纯 EP 相比，EP/TA-MoS2-NMFe 的峰值放热率、总放热率、峰值发烟率和发烟系数分别降低了 42.3%、41.2%、50.8% 和 71.1%，优于已有报道。这主要得益于金属离子的催化成碳作用、TA 的膨胀炭化特性、MoS2 的阻隔作用和不可燃气体的稀释作用。简而言之，这项工作为从仿生学角度开发高性能聚合物提供了一条创新之路。

Investigation of nanocomposite system with long-chain phosphorus-containing intercalator-modified Montmorillonite nanosheets

Zhang Shenghe, Chu Fukai, Hu Weizhao, Wang Bibo, Yuen Richard K.K., Hu Yuan

doi:10.1016/j.compositesa.2023.107877

含长链磷插层剂改性蒙脱石纳米片的纳米复合材料系统研究

The biodegradable polyester polybutylene adipate-co-terephthalate (PBAT) is a synthetic material that can melt and ignite easily when exposed to fire. Herein, we synthesized a long-chain phosphorus-containing intercalator by grafting 9,10-dihydro-9-oxa-10-phos-phaphenanthrene10-oxide (DOPO) onto long-chain quaternary ammonium salts (BHMDAC). Then inserted it into the sodium-based montmorillonite (MMT) nanosheets at the ratio of 25.9 wt% to obtain organic modified nanosheets. Subsequently, they were mixed into the PBAT matrix, and a series of performance such as microscopic dispersion, thermal stability, flame retardancy, mechanism and mechanical properties of nanocomposite were investigated. Compared with PBAT (1138.42 kW/m2), PBAT/MMT-(DOPO-BHMDAC) 5 wt% exhibited the lowest peak heat release rate value (508.04 kW/m2), which was reduced by 55.37 %. After adding 1 wt% MMT/DOPO-BHMDAC, the tensile strength of the sample increased from 25.1 MPa to 32.0 MPa, and the elongation at break increased to 826%. This work provides a new perspective for future research on high-performance degradable polyester materials.

可生物降解聚酯聚己二酸丁二醇酯（PBAT）是一种遇火容易熔化和燃烧的合成材料。在此，我们将 9,10-二氢-9-氧杂-10-磷菲10-氧化物（DOPO）接枝到长链季铵盐（BHMDAC）上，合成了一种长链含磷插层剂。然后将其按 25.9% 的比例加入钠基蒙脱石（MMT）纳米片中，得到有机改性纳米片。随后，将它们混合到 PBAT 基体中，研究了纳米复合材料的微观分散性、热稳定性、阻燃性、机理和力学性能等一系列性能。与 PBAT（1138.42 kW/m2）相比，PBAT/MMT-(DOPO-BHMDAC) 5 wt%的热释放率峰值最低（508.04 kW/m2），降低了 55.37 %。添加 1 wt% MMT/DOPO-BHMDAC 后，样品的拉伸强度从 25.1 MPa 提高到 32.0 MPa，断裂伸长率提高到 826%。这项研究为今后高性能可降解聚酯材料的研究提供了新的视角。

Composites Science and Technology

Ultra-thin composites membrane for deployable structures: XCT driven characterization and FE modeling of folding structure

Din Israr Ud, Ahmed Adnan, Tarek Farah, Cantwell Wesley, Khan Kamran A.

doi:10.1016/j.compscitech.2023.110341

 

用于可部署结构的超薄复合材料膜：折叠结构的 XCT 驱动表征和 FE 建模

Light-weight, ultra-thin, high performance, origami-inspired deployable folding structures can be fabricated by simulating various designs and material combinations. In this study, an XCT-driven finite element (FE) model of a building block in a typical full-scale origami structure consisting of stiff and fold regions was developed. Following our previous work, the stiff region of the fold sample was fabricated using a hot compression molding technique whereas hand layup was employed for the fold region. XCT-driven FE based homogenization was carried out on an RVE of real microstructure of both ultra-thin composite laminates. The FE homogenization results were found to be in good agreement with the experimentally-measured effective stiffness properties of both the stiff and fold regions, with a maximum error of ∼10%. Folding tests were conducted on a simple fold and the force vs. displacement and moment vs. curvature curves were plotted. The applicability of XCT-driven FE modeling to simulate foldable structures were demonstrated using post-buckling and bending analysis available in the FE software ABAQUS®. A uniform and symmetric fold curvature, along with the corresponding force vs. displacement response were predicted using XCT-driven FE techniques and found to be in good agreement with data from the experimental tests. The peak force predicted by the FE model showed an error of ∼5.2% compared to the experimental fold test.

通过模拟各种设计和材料组合，可以制造出轻质、超薄、高性能、受折纸启发的可部署折叠结构。在本研究中，我们开发了一个 XCT 驱动的有限元（FE）模型，该模型是由刚性区域和折叠区域组成的典型全尺寸折纸结构中的一个构件。根据我们之前的工作，折纸样品的刚性区域采用热压成型技术制造，而折叠区域则采用手糊工艺。在两种超薄复合材料层压板真实微观结构的 RVE 上进行了基于 XCT 驱动的 FE 均质化。结果表明，FE 均质化结果与实验测量的刚度和折叠区域的有效刚度特性十分吻合，最大误差为 10%。对简单折叠进行了折叠试验，并绘制了力与位移和力矩与曲率的关系曲线。利用 FE 软件 ABAQUS® 中的后屈曲和弯曲分析，证明了 XCT 驱动的 FE 建模在模拟可折叠结构方面的适用性。使用 XCT 驱动的有限元技术预测了均匀对称的折叠曲率以及相应的力与位移响应，结果发现与实验测试数据非常吻合。FE 模型预测的峰值力与实验折叠测试的误差为 5.2%。