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【新文速递】2024年8月2日复合材料SCI期刊最新文章

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今日更新:Composite Structures 10 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Science and Technology 3 篇

Composite Structures

An experimental-analytical investigation of particle size effect on the mode I fracture behavior of polymer/graphene nanocomposites

Sara Amirahmadi, Sankha Aditya, Samit Roy

doi:10.1016/j.compstruct.2024.118420

颗粒尺寸对聚合物/石墨烯纳米复合材料I型断裂行为影响的实验分析研究

Due to their outstanding specific mechanical and functional properties, the engineering use of polymer nanocomposites and their carbon composites is becoming increasingly pervasive. Current and potential applications include micro- and flexible electronics, energy storage devices, and the use as reinforcement for advanced carbon fiber composites for light-weighting of aerospace and mechanical structures, thereby reducing their fuel consumption and carbon footprint. While a large amount of data and models regarding the effect of the weight fraction of nanoplatelets on the mechanical properties of nanocomposites is currently available in the literature, an aspect often overlooked is the scaling of the fracture behavior and the related particle size effects. Not only is the lack of understanding of size effects in nanomaterials hindering the full exploitation of their properties, it is also a serious issue since the design of large nanocomposite structures or small-scale electronic components requires capturing the scaling of their mechanical properties and developing predictive capabilities. This paper aims at filling this knowledge gap by proposing a novel analytical and experimental approach to investigate particle size effects in nanocomposites at and leveraging the acquired knowledge to improve their fracture properties, from the nanoscale all the way to the macroscale. To this end, crack initiation fracture toughness data for graphene/epoxy nanocomposite are presented as a function of nanoparticle size and weight fraction and compared with model predictions using a novel analytical model based on enhanced crack-tip shielding effect due to the reduced nanoparticle size. Extensive fracture test data are presented for model calibration and model verification.

由于聚合物纳米复合材料及其碳复合材料具有优异的机械性能和功能特性,其工程应用日益广泛。目前和潜在的应用包括微型和柔性电子产品、能量存储设备,以及用作航空航天和机械结构轻量化的先进碳纤维复合材料的增强材料,从而降低其燃料消耗和碳足迹。虽然目前文献中有大量关于纳米薄片重量分数对纳米复合材料力学性能影响的数据和模型,但一个经常被忽视的方面是断裂行为的尺度和相关的粒径效应。缺乏对纳米材料尺寸效应的理解不仅阻碍了其性能的充分利用,而且由于大型纳米复合材料结构或小型电子元件的设计需要捕获其机械性能的缩放并开发预测能力,这也是一个严重的问题。本文旨在通过提出一种新的分析和实验方法来研究纳米复合材料中的颗粒尺寸效应,并利用所获得的知识来改善纳米复合材料的断裂性能,从纳米尺度一直到宏观尺度。为此,将石墨烯/环氧纳米复合材料的裂纹起裂韧性数据作为纳米颗粒尺寸和重量分数的函数,并使用基于纳米颗粒尺寸减小导致裂纹尖端屏蔽效应增强的新型分析模型与模型预测进行了比较。提供了大量的断裂试验数据,用于模型校准和模型验证。


The deployment of 3-D morphing surfaces: A 2-D auxetic metamaterial approach through buckling-induced mechanism

Chengyang Lu, Ruizhi Li, Yifan Zheng, Fei Pan, Yuli Chen, Xiaotian Zhang

doi:10.1016/j.compstruct.2024.118432

三维变形表面的展开:一种基于屈曲诱导机制的二维形变超材料方法

The 3-dimensional shape morphing is desired in applications such as aerospace, soft robotics and medical devices. Via the arrangement of auxetic cells, this paper proposes a box-shaped morphing block concept consisting of 2-dimensional metamaterial to realize 3D shape morphing driven through the structural buckling approach. Firstly, the expansion, bending and twisting deformation modes of the morphing block distinguished by varied Poisson’s ratio arrangement of the auxetic face cells on boundary lattices are introduced. Then, we verify the deployment of 3D deformation through a series of quasi-static tensile experiments, which present a good agreement with our simulation results and demonstrate the effectiveness of induced buckling mechanism. Finally, more complex morphing features are realized by a hybrid combination of the different deformation modes, while their deployment mechanisms are discussed. This morphing block concept with tailorable shape-shifting capability can be an excellent candidate in the 3D morphing structure application.

在航空航天、软机器人和医疗设备等应用中需要三维形状变形。本文提出了一种由二维超材料组成的箱形变形块概念,通过结构屈曲驱动实现三维形状变形。首先,介绍了变形块的膨胀、弯曲和扭转变形模式,这些变形块是由边界格上的异形面单元的不同泊松比排列来区分的。然后,我们通过一系列的准静态拉伸实验验证了三维变形的部署,结果与我们的模拟结果吻合良好,证明了诱导屈曲机制的有效性。最后,通过不同变形模式的混合组合实现了更复杂的变形特征,并讨论了它们的展开机制。这种具有可定制变形能力的变形块概念在三维变形结构应用中具有良好的应用前景。


SiCp/Al composites from conventional to empowered machining: Mechanisms and processability

Dewei Liu, Changhe Li, Peiming Xu, Wei Wang, Yanbin Zhang, Min Yang, Xin Cui, Benkai Li, Mingzheng Liu, Teng Gao, Yusuf Suleiman Dambatta, Aiguo Qin

doi:10.1016/j.compstruct.2024.118433

SiCp/Al复合材料从传统加工到强化加工:机理和可加工性

SiCp/Al composites, known for their outstanding properties, are widely used in aerospace, automotive, and other fields. Despite extensive research, a complete theoretical framework and evaluation system for processing these composites have not yet been established. To enhance their processability, it is crucial to understand how processing-induced characteristics affect their machinability and to establish a robust evaluation system. This study addresses this gap by first reviewing the influence of particle properties on the mechanical properties of SiCp/Al composites. Next, both conventional and advanced machining mechanisms are analyzed, and the processability based on the cutting/grinding forces and surface roughness is evaluated. The results show that advanced machining techniques significantly improve processability compared to conventional methods. The ultrasonic elliptical vibration-assisted turning of the 25 vol% SiCp/Al6061 composites resulted in an 82.4% reduction in the cutting force. Laser-assisted turning of 45 vol% SiCp/Al composites achieved an 89.8% improvement in surface roughness (Sa). Finally, we identify research gaps and future challenges in processing SiCp/Al composites, providing technical support and theoretical guidance for both industry and academia.

SiCp/Al复合材料以其优异的性能而闻名,广泛应用于航空航天、汽车等领域。尽管进行了广泛的研究,但尚未建立完整的加工这些复合材料的理论框架和评价体系。为了提高其可加工性,了解加工诱发特性如何影响其可加工性并建立健全的评价体系至关重要。本研究首先回顾了颗粒性能对SiCp/Al复合材料力学性能的影响,从而解决了这一空白。其次,分析了传统和先进的加工机构,并基于切削/磨削力和表面粗糙度评估了可加工性。结果表明,与传统加工方法相比,先进的加工技术显著提高了加工性能。超声椭圆振动辅助车削25 vol% SiCp/Al6061复合材料的切削力降低了82.4%。激光辅助车削45 vol% SiCp/Al复合材料的表面粗糙度(Sa)提高了89.8%。最后,我们确定了SiCp/Al复合材料加工的研究差距和未来挑战,为工业界和学术界提供了技术支持和理论指导。


Bio-inspired topology optimization driven design for 3D printed radially graded meta-structures; Design, modeling and mechanical characteristics

Khalegh Kouhi-Lakeh, Mohsen Teimouri, Masoud Asgari

doi:10.1016/j.compstruct.2024.118435

三维打印径向梯度元结构仿生拓扑优化驱动设计设计,建模和机械特性

This study is focused on applying a topology optimization-driven design procedure on a predefined radial design domain to generate bio-inspired radially graded porous structures which are suitable to be used as energy absorbers and lightweight structures, bone scaffolds and implants in biomechanical applications. A topology optimization method is applied on two predefined design domains as well as a theoretical design approach based on geometrical parameters. In this regard, the optimized structures are geometrically studied and the design areas are formulated parametrically. The topology-optimized graded structures have been manufactured using the SLA 3D printing technology for sample compression tests. Numerical and experimental approaches are applied to them simultaneously and the finite element analyses (FEA) are verified. Finally, a parametric study is done to study the effects of the design variables on the architecture of generated designs and their mechanical properties, revealing a non-linear relation between design variables and properties. This study proposes a theoretical design method based on a topology-optimized design domain. A parametric study has been done, which allows designers to produce various geometries and choose the best one according to their needs. The design step is followed by mechanical characterization of the novel radial structures using experimentally-validated FE analyses.

本研究的重点是在预定义的径向设计域上应用拓扑优化驱动设计程序,生成仿生径向梯度多孔结构,该多孔结构适用于生物力学应用中的能量吸收器和轻质结构,骨支架和植入物。在两个预先确定的设计域上采用拓扑优化方法和基于几何参数的理论设计方法。在这方面,优化结构进行了几何研究,并制定了参数化设计区域。利用SLA 3D打印技术制造了拓扑优化的梯度结构,并进行了样品压缩测试。采用数值和实验相结合的方法对其进行了分析,并对有限元分析结果进行了验证。最后,进行了参数化研究,研究了设计变量对生成设计的结构及其力学性能的影响,揭示了设计变量与力学性能之间的非线性关系。本研究提出一种基于拓扑优化设计域的理论设计方法。进行了参数化研究,使设计人员能够产生各种几何形状,并根据他们的需要选择最佳的几何形状。设计步骤之后是利用实验验证的有限元分析对新型径向结构进行力学表征。


Parametric optimization framework for designing sandwich panels with auxetic core subjected to impact load

Edinilson A. Costa, Larissa Driemeier

doi:10.1016/j.compstruct.2024.118436

抗冲击夹层板减芯设计的参数化优化框架

An auxetic material can use the negative Poisson ratio to make the impact area denser and better absorb energy. This unique behavior can be exploited for building sandwich panels that absorb more energy per unit of weight. This work proposes a methodology to design lightweight auxetic-core sandwich panels with enhanced impact energy absorption capability. The method is based on an optimization framework whose function is a parameterized Finite Element model of a 3D auxetic structure. Metamodeling is used instead of direct optimization. The performance of different surrogate models, including Artificial Neural Networks, are computed and the best-ranked model is used for the subsequent optimization task carried-out with the aid of a genetic algorithm. The applicability of the framework is demonstrated by creating a sandwich panel with a 3D reentrant auxetic core subjected to a ballistic load, which is 36% lighter than the baseline design and 28% thinner than the literature reference honeycomb sandwich.

减振材料可以利用负泊松比使冲击区域更致密,吸收能量更好。这种独特的性能可以用于建造每单位重量吸收更多能量的夹层板。这项工作提出了一种设计具有增强冲击能量吸收能力的轻质异形芯夹芯板的方法。该方法基于优化框架,其函数是三维结构的参数化有限元模型。使用元建模代替直接优化。计算了包括人工神经网络在内的不同代理模型的性能,并将排名最高的模型用于借助遗传算法执行的后续优化任务。该框架的适用性通过创建一个具有三维可入式辅助核心的夹层板来证明,该夹层板承受弹道载荷,比基准设计轻36%,比文献参考蜂窝夹层薄28%。


Prediction of bond strength and failure mode of FRP bars embedded in UHPC or UHPSSC utilising extreme gradient boosting technique

Pei-Fu Zhang, Xiao-Ling Zhao, Daxu Zhang, Mudassir Iqbal, Xuan Zhao, Qi Zhao, Yiliyaer Tuerxunmaimaiti, Congshui Yu

doi:10.1016/j.compstruct.2024.118437

利用极端梯度增强技术预测嵌入UHPC或UHPSSC的FRP筋的粘结强度和破坏模式

The bond strength and failure mode of fibre-reinforced polymer (FRP) bars embedded in ultra-high-performance concrete (UHPC) and ultra-high-performance seawater sea sand concrete (UHPSSC) are significant to ensure the structural integrity of FRP-UHPC/UHPSSC structures. Given the multiplicity influencing bond interaction, conventional methods face challenges in developing predictive models and equations. For precise prediction and comprehensive investigation of bond performance in FRP-UHPC/UHPSSC, this paper employed an effective approach utilising extreme gradient boosting (XGBoost) technique to predict bond strength and failure mode. Two XGBoost predictive models were established based on a dataset comprising 542 data points with 14 input parameters. The developed models demonstrated reliable performances through an exhaustive assessment. SHAP (SHapley Additive exPlanations) analysis was employed to study the influences of input variables considering the bond mechanism. Specifically, the bonded-length-to-diameter ratio is pivotal in bond strength prediction, followed by FRP surface properties, concrete compressive strength and cover-to-diameter ratio; while cover-to-diameter ratio, bar diameter and concrete compressive strength stand out in failure mode prediction. Furthermore, explicit SHAP-based bond strength predictive equations were derived for concrete splitting and pullout failures. The developed model and equation demonstrate a closer approximation to experimental results compared to that in ACI 440.1R-15

纤维增强聚合物(FRP)筋在高性能混凝土(UHPC)和高性能海水海砂混凝土(UHPSSC)中的粘结强度和破坏模式对保证FRP-UHPC/UHPSSC结构的完整性具有重要意义。考虑到影响键相互作用的多样性,传统方法在建立预测模型和方程方面面临挑战。为了准确预测和全面研究FRP-UHPC/UHPSSC的粘结性能,本文采用了一种有效的方法,利用极端梯度增强(XGBoost)技术来预测粘结强度和破坏模式。基于包含542个数据点和14个输入参数的数据集,建立了两个XGBoost预测模型。通过详尽的评估,所开发的模型显示了可靠的性能。采用SHapley加性解释(SHapley Additive explanatory, SHapley可加性解释)分析,考虑键合机制,研究输入变量的影响。具体而言,粘结长径比是预测粘结强度的关键,其次是FRP表面性能、混凝土抗压强度和覆盖直径比;而覆盖直径比、钢筋直径和混凝土抗压强度在破坏模式预测中较为突出。此外,导出了基于shap的混凝土劈裂和拉拔破坏的显式粘结强度预测方程。与aci440.1 r -15相比,所建立的模型和方程更接近实验结果


Damage characterization of CFRP /steel double-lap bonded joints based on AE and DIC

Zhiyuan Zhang, Changhang Xu, Jing Xie, Xueying Sun, Wenao Wang, Na Li

doi:10.1016/j.compstruct.2024.118441

基于声发射和DIC的CFRP /钢双搭接接头损伤表征

CFRP/steeljoints are commonly used in construction and can cause unpredictable damage when subjected to external loading. However, it is still challenging tocharacterize the damage evolution behavior of joints under different loads. In this study, acoustic emission (AE) and digital image correlation (DIC) techniques are used to monitor the damaged state of joints, and a decision tree (DT) algorithm was proposed. From the monitoring results of AE and DIC, it can be found that the damage process of the joint is divided into three stages and is mainly accompanied by four damage modes, namely adhesive failure, cohesive failure, skin failure, and steel deformation. In addition, it also reveals that the AE signal is more sensitive to the early damage of the joint, while the DIC is more sensitive to the late damage of the joint. The identification results of the DT algorithm show that the main damage mechanisms of the joints under the tensile loading conditions are adhesive failure and cohesive failure, while the primary damage mechanism under the bending loading conditions is adhesive failure. The combination of these two techniques successfully enables the damage characterization of joints and provides a framework for analyzing the damage mechanisms of joints.

CFRP/钢节点通常用于建筑中,当受到外部载荷时可能造成不可预测的损伤。然而,表征不同荷载作用下节点的损伤演化行为仍然是一个挑战。本文采用声发射(AE)和数字图像相关(DIC)技术对关节损伤状态进行监测,并提出了一种决策树(DT)算法。从声发射和DIC的监测结果可以发现,接头的损伤过程分为三个阶段,主要伴随着粘结破坏、内聚破坏、蒙皮破坏和钢材变形四种损伤模式。此外,还揭示了声发射信号对关节早期损伤更敏感,而DIC对关节晚期损伤更敏感。DT算法的识别结果表明,在拉伸加载条件下,接头的主要损伤机制为粘结破坏和内聚破坏,而在弯曲加载条件下,接头的主要损伤机制为粘结破坏。这两种技术的结合成功地实现了关节损伤表征,为分析关节损伤机理提供了框架。


Compression-compression fatigue damage of wrinkled carbon/glass hybrid composite laminates

Xing-Yuan Miao, Xiao Chen, Steffen Rasmussen, Malcolm McGugan

doi:10.1016/j.compstruct.2024.118443

起皱碳/玻璃杂化复合材料层合板的压缩疲劳损伤

Compression-compression fatigue tests were carried out to study the compressive fatigue damage mechanisms of a carbon/glass hybrid composite laminate with a manufacturing-induced wrinkle defect. As reported in literature, thin wrinkled composite laminates could show sensibly different fatigue behaviours and damage mechanisms in the presence of tension and compression cyclic loadings. The sensitivities of composites to tension and compression cyclic loadings were not the same. In this study, the damage modes and cracking sequence of a thick wrinkled laminate were identified by the strain fields from digital image correlation (DIC). Acoustic emission (AE) and infrared (IR) thermography were used to detect the damages and explore the potential capabilities of non-destructive evaluation methods when applied to detection of fatigue induced damages in composite structures under operational cyclic loadings. Two primary damage modes were identified and detected before the final failure of the laminate i.e. debonding between the resin-rich layer and the laminate and interlaminar cracks. Debonding occurred earlier than interlaminar cracking. Out-of-plane stresses due to fibre waviness drove the initiation of these damages. Under the settings of AE in this study AE captured early debonding activities but did not detect the micro damage accumulating before the formation of interlaminar crack. Interlaminar crack initiation was tracked by IR thermography at cross-section of the specimen based on the distinct temperature localisations that occur with this micro damage. No distinct temperature localisations occurred during the formation of debonding as it is mode-I driving under compression-compression cyclic loading, so IR thermography did not detect the debonding crack. The results of this study show the potential of using complementary non-destructive damage evaluation methods to inspect early damages in composite structures. The early detection of damages would give early warning signs before the damages become critical. It is found that AE and IR thermography should be used as complementary tools to detect different damage modes.

采用压缩-压缩疲劳试验研究了一种带有制造诱导褶皱缺陷的碳/玻璃杂化复合材料层合板的压缩疲劳损伤机理。据文献报道,薄皱复合材料层合板在拉伸和压缩循环载荷下表现出明显不同的疲劳行为和损伤机制。复合材料对拉伸和压缩循环载荷的敏感性不相同。利用数字图像相关(DIC)的应变场识别厚起皱层压板的损伤模式和开裂顺序。利用声发射(AE)和红外(IR)热成像技术对复合材料结构进行损伤检测,探索无损评价方法在循环荷载作用下检测复合材料结构疲劳损伤的潜力。在层板最终破坏前,识别并检测到两种主要的破坏模式,即富树脂层与层板之间的脱粘和层间裂纹。剥离发生早于层间开裂。纤维波纹性引起的面外应力导致了这些损伤的发生。在本研究的声发射设置下,声发射捕获了早期的脱粘活动,但没有检测到层间裂纹形成之前积累的微损伤。基于这种微损伤产生的不同温度定位,通过红外热像仪在试样的横截面上跟踪层间裂纹的起裂。由于在压缩-压缩循环加载下为i型驱动,在脱粘形成过程中没有明显的温度局部化,因此红外热像仪未检测到脱粘裂纹。本研究结果显示了利用互补无损损伤评估方法检测复合材料结构早期损伤的潜力。损害的早期发现可以在损害变得严重之前提供早期预警信号。发现声发射和红外热成像可以作为互补工具来检测不同的损伤模式。


Energy absorption assessment of recovered shapes in 3D-printed star hourglass honeycombs: Experimental and numerical approaches

Amin Farrokhabadi, Houyu Lu, Xin Yang, Ali Rauf, Reza Talemi, Amir Hossein Behravesh, Seyyed Kaveh Hedayati, Dimitrios Chronopoulos

doi:10.1016/j.compstruct.2024.118444

3d打印星形沙漏蜂窝恢复形状的能量吸收评估:实验和数值方法

This study provides an experimental and numerical evaluation of the energy absorption performance of a 3D-printed star hourglass honeycomb structure with a novel design made from pure and reinforced PLA by chopped carbon fibers and continuous glass fiber. The study further investigates the energy absorption response of this structure after the shape recovery due to thermal stimuli under the quasi-static compressive loading. As an additive manufacturing process, Fused Deposition Modeling is used to produce the specimens with pure and reinforced PLA filament. The difference in the nonlinear response of PLA due to plasticity and damage in tension and compression loading directions, as a feature that helps the shape recovery, is considered in mechanical response analysis using the Finite Element approach. Then, in the obtained results distinguish constitutive laws in tension and compression mechanical properties are employed leading to a failure model using the appropriate algorithm consistent with the experiments. According to the obtained results which reveal good agreement regarding the experimental results, by designing appropriate auxetic configuration selecting suitable geometry parameters, and employing the proper material with diverse properties in tension and compression directions, it is possible to fabricate a lattice structure inherits the shape recovery after the compression deformation which exhibits acceptable energy absorption performance even the second shape recovery.

本研究通过实验和数值方法对一种新型的3d打印星形沙漏蜂窝结构的吸能性能进行了评估。该结构由纯聚乳酸增强,由短切碳纤维和连续玻璃纤维制成。进一步研究了在准静态压缩载荷作用下,该结构在热刺 激下恢复形状后的能量吸收响应。作为一种增材制造工艺,熔融沉积建模被用于生产纯PLA和增强PLA长丝的样品。利用有限元方法进行力学响应分析时,考虑了PLA在拉伸和压缩加载方向上由于塑性和损伤引起的非线性响应差异,这是一种有助于形状恢复的特征。然后,在得到的结果中,区分拉伸和压缩力学性能的本构规律,采用与实验相一致的适当算法建立失效模型。所得结果与实验结果吻合较好,通过设计适当的形变构型,选择合适的几何参数,采用适当的拉伸和压缩方向性能不同的材料,可以制造出继承压缩变形后形状恢复的晶格结构,即使是第二次形状恢复也具有良好的吸能性能。


A novel strategy for constructing electro-conductive segregated network of polyphenylene sulfide-based foam enables electromagnetic shielding effectiveness

Xinyi Liu, Zun Yuan, Yuanchun Zhang, Ping Xu, Xiaowen Zhao, Yun Yu, Lin Ye

doi:10.1016/j.compstruct.2024.118446

 

一种新型的聚苯硫醚基泡沫导电隔离网络构建策略,使其具有良好的电磁屏蔽效果

Developing polyphenylene sulfide (PPS)-based electromagnetic shielding foam is significant to broaden its applications in aerospace, electronic communications, etc., while introducing too many conductive fillers induced poor foaming ability of PPS. In this work, the skinless PPS foamed beads (S-PPS) were prepared, and coated with epoxy (EP)/carbon nanotubes (CNT) conductive interface layer, while the porous structure of bead surface greatly enhanced interface interaction between the two phases by forming interfacial mechanical interlocking structure with high adhesive strength. Thereby S-PPS@EP/CNT foam with conductive segregated network was obtained by surface adhesion-assisted molding method of supercritical CO2 (scCO2) bead foaming. CNTs were dispersed uniformly and entangled with each other in interface layer, and the conductivity of interface layer and S-PPS@EP/CNT foam increased remarkably with extremely low percolation threshold, attributed to confined distribution of CNTs in interface layer, and perfect conductive segregated network formed at lower CNT content. With increasing CNT content, the complex permittivity, dielectric loss factor and conductivity of foams increased, so that the ability to attenuate electromagnetic waves through polarization loss and conductivity loss was enhanced, showing significantly improved electromagnetic shielding performance and absorption-based shielding mechanism. This work provided a facile and innovative way for fabrication of PPS-based electromagnetic shielding foam.

开发基于聚苯硫醚(PPS)的电磁屏蔽泡沫对拓宽其在航空航天、电子通信等领域的应用具有重要意义,但过多导电填料的引入会导致 PPS 的发泡能力变差。本研究制备了无皮 PPS 发泡珠子(S-PPS),并在其表面涂覆了环氧树脂(EP)/碳纳米管(CNT)导电界面层,而珠子表面的多孔结构大大增强了两相之间的界面相互作用,形成了具有高粘合强度的界面机械互锁结构。因此,通过超临界二氧化碳(scCO2)微珠发泡的表面粘附辅助成型方法,获得了具有导电离析网络的 S-PPS@EP/CNT 泡沫。CNT在界面层中均匀分散并相互缠结,界面层和S-PPS@EP/CNT泡沫的导电率显著提高,渗流阈值极低,这归功于CNT在界面层中的密闭分布,并且在CNT含量较低时形成了完美的导电隔离网络。随着 CNT 含量的增加,泡沫的复介电常数、介质损耗因数和电导率也随之增加,从而提高了通过极化损耗和电导率损耗衰减电磁波的能力,显著改善了电磁屏蔽性能和基于吸收的屏蔽机理。这项工作为制备基于 PPS 的电磁屏蔽泡沫提供了一种简便、创新的方法。


Composites Part A: Applied Science and Manufacturing

Integrating experimental and numerical analyses for microscale tensile behavior of ceramic particle reinforced TRIP steel composites: A study on local deformation and damage evolution

ChenChun Chiu, Vimal Prabhakar, ShaoChen Tseng, Faisal Qayyum, Sergey Guk, ChingKong Chao, Ulrich Prahl

doi:10.1016/j.compositesa.2024.108384

 

陶瓷颗粒增强TRIP钢复合材料微尺度拉伸行为的实验与数值分析:局部变形与损伤演化研究

This study investigates deformation, interfacial, and particle damage in a magnesium-partially stabilized zirconia (Mg-PSZ) particle-reinforced transformation-induced plasticity (TRIP) steel composite using SEM in situ tensile tests and finite element simulations. The simulation models employ an elastic model for ceramic particles and a Johnson-Cook plastic model for the matrix, considering individual perfect cohesive zone model (CZM) and combined CZM/extended finite element method (XFEM) models along the interface. The simulation and experimental results are qualitatively and quantitatively consistent for the initiation and evolution of interfacial and particle failure with a relative error in crack length of only 4.6 %. Furthermore, crack propagation analysis by the debonding angle reveals that damage starts earlier with a sharper particle geometry. Prioritizing non-linear interfacial morphologies in particles and controlling reinforcement edges perpendicular to the loading can achieve lower and constrained debonding angles, thereby continuing to provide a strengthening effect and finally enhancing material behavior.

本研究利用SEM原位拉伸试验和有限元模拟研究了镁-部分稳定氧化锆(Mg-PSZ)颗粒增强相变诱发塑性(TRIP)钢复合材料的变形、界面和颗粒损伤。仿真模型采用陶瓷颗粒的弹性模型和基体的Johnson-Cook塑性模型,考虑了沿界面的单个完美黏聚区模型(CZM)和CZM/扩展有限元法联合模型(XFEM)。模拟结果与实验结果在定性和定量上基本一致,裂纹长度的相对误差仅为4.6%。此外,裂纹扩展分析通过剥离角揭示损伤开始早,更尖锐的颗粒几何形状。优先考虑颗粒中的非线性界面形态,并控制垂直于加载的增强边缘,可以实现较低的约束脱粘角,从而继续提供强化效果,最终提高材料性能。


Composites Science and Technology

Coaxial direct ink writing of ZnO functionalized continuous carbon fiber-reinforced thermosetting composites

Zhuoyuan Yang, Evan Medora, Zefu Ren, Meng Cheng, Sirish Namilae, Yizhou Jiang

doi:10.1016/j.compscitech.2024.110782

 

ZnO功能化连续碳纤维增强热固性复合材料的同轴直墨书写

Additive manufacturing of fiber-reinforced thermosetting composites is of great importance for various applications. However, improving the quality of the fiber/matrix interface under various additive manufacturing processes is still in the early stages. Herein, for the first time, we report the coaxial direct ink writing of zinc oxide (ZnO) functionalized continuous carbon fiber-reinforced thermosetting polymer composites. Both elastomeric and rigid thermosetting polymers reinforced with ZnO functionalized continuous carbon fiber composites can be printed into single filaments with turning angles and multi-layer tall arbitrary structures. The printed ZnO functionalized epoxy composites achieve Young's modulus of 3.69 GPa, which is 15.3% higher than pristine fiber-reinforced composites. The printed composite exhibits resistance under various environmental conditions. Additionally, ZnO functionalization significantly enhanced the fiber-matrix interface strength, with improvements of 57%. The reduced modulus of ZnO functionalized fibers is 174% higher than that of pristine fibers. ZnO nanowires enhance the heating transfer rate of carbon fibers by 17% within the same heating time. Our innovative coaxial direct ink writing offers a general strategy for multi-material printing, laying the groundwork for future additive manufacturing of functional composite devices and structures with enhanced performance.

增材制造纤维增强热固性复合材料在各种应用中具有重要意义。然而,在各种增材制造工艺下,提高纤维/基体界面质量仍处于早期阶段。在此,我们首次报道了氧化锌功能化连续碳纤维增强热固性聚合物复合材料的同轴直接墨水书写。用ZnO功能化连续碳纤维复合材料增强弹性体和刚性热固性聚合物都可以打印成具有转角的单长丝和多层高任意结构。打印的ZnO功能化环氧复合材料的杨氏模量为3.69 GPa,比原始纤维增强复合材料高15.3%。打印的复合材料在各种环境条件下都具有良好的耐受性。此外,ZnO功能化显著提高了纤维-基体界面强度,提高了57%。氧化锌功能化纤维的还原模量比原始纤维高174%。在相同的加热时间内,ZnO纳米线使碳纤维的传热速率提高了17%。我们创新的同轴直接墨水书写为多材料打印提供了一种通用策略,为未来功能复合材料器件和结构的增材制造奠定了基础。


Customizable 3D-printed decoupled structural lithium-ion batteries with stable cyclability and mechanical robustness

Xu Ma, Yinhua Bao, Na Li, Bo Lu, Yicheng Song, Junqian Zhang, Daining Fang

doi:10.1016/j.compscitech.2024.110783

可定制的3d打印解耦结构锂离子电池,具有稳定的可循环性和机械稳健性

Structural batteries are considered one of the promising strategies for improving the endurance of electric vehicles. However, the trade-off between load-bearing capability and electrochemical performance remains a significant challenge. This paper proposes an efficient 3D printing-assisted fabrication strategy for high-performance structural batteries with customizable geometric configurations. The composite structural battery sample shows a bending modulus of 24.5 GPa, which could withstand maximum tensile stress and three-point bending stress of 155 MPa (specific tensile strength of 88340 N m kg-1) and 123 MPa (specific bending strength of 61553 N m kg-1). Meanwhile, it can achieve a high energy density of 120 Wh kg-1 and 210 Wh L-1 (3.5 mA cm-2) and superior capacity retention of up to 92% after 500 cycles (10.5 mA cm-2). More importantly, the in-situ mechanical-electrochemical test demonstrates exceptional performance, retaining an ultra-high capacity of 98.7% under a tensile stress of 80 MPa, and maintaining a capacity retention rate of 97 % with an average capacity decay per cycle of only 0.18 % under a bending stress of 96.3 MPa. In addition, finite element analysis is also used to verify the failure mechanism of the battery under bending load. Meanwhile, the fabricated structural battery can be applied to autonomous mobile robots, showing the multifunction energy storage and load-bearing. As a result, this work showcases the great potential of incorporating high-performance structural batteries into engineering applications such as small-scale warehousing, logistics equipment, and intelligent robotics.

结构电池被认为是提高电动汽车续航能力的有前途的策略之一。然而,在承载能力和电化学性能之间的权衡仍然是一个重大挑战。本文提出了一种高效的3D打印辅助制造策略,用于具有可定制几何结构的高性能结构电池。复合材料结构电池样品的弯曲模量为24.5 GPa,可承受最大拉伸应力155 MPa(比拉伸强度88340 N m kg-1)和三点弯曲应力123 MPa(比弯曲强度61553 N m kg-1)。同时,它可以实现120 Wh kg-1和210 Wh L-1 (3.5 mA cm-2)的高能量密度,并在500次循环(10.5 mA cm-2)后保持高达92%的卓越容量。更重要的是,原位力学电化学测试显示了优异的性能,在80 MPa的拉伸应力下保持了98.7%的超高容量,在96.3 MPa的弯曲应力下保持了97%的容量保持率,平均每循环容量衰减仅为0.18%。此外,还采用有限元分析验证了电池在弯曲载荷作用下的失效机理。同时,制造的结构电池可应用于自主移动机器人,显示出多功能储能和承载能力。因此,这项工作展示了将高性能结构电池纳入小型仓储、物流设备和智能机器人等工程应用的巨大潜力。


Loading rate effect on the shear behavior of the carbon fiber/epoxy interface

Kai Yan, Xunqiandi Cao, Ximing Xie, Haijuan Mei, Jianbo Tang, Xiangyu Sun, Fuzeng Ren

doi:10.1016/j.compscitech.2024.110785

 

加载速率对碳纤维/环氧树脂界面剪切性能的影响

Carbon fiber (CF)/epoxy (EP) composites are widely used in structural components. Quasistatic and dynamic shear experiments were designed and conducted to investigate the effect of the loading rate on the shear behavior of the CF/EP interface. Using numerical simulation, the accuracy of the new shear testing methods to test the shear behavior of interface under both quasistatic and dynamic loading conditions was verified. The shear failure stress increases with increasing loading rate, and the failure mode of the CF/EP interface changes from fiber-matrix debonding to almost entirely brittle fracture of the matrix and fiber-matrix debonding. The proposed dynamic shear test method is promising for testing the shear behavior of interface between two kinds of materials or phases, and the shift in the failure mode is a consequence of the effect of the loading rate on the shear behavior of the CF/EP interface.

碳纤维(CF)/环氧树脂(EP)复合材料在结构部件中有着广泛的应用。设计了准静态和动态剪切实验,研究了加载速率对CF/EP界面剪切性能的影响。通过数值模拟,验证了新剪切试验方法在准静态和动加载条件下测试界面剪切性能的准确性。剪切破坏应力随加载速率的增加而增大,CF/EP界面的破坏模式由纤维-基体脱粘转变为基体和纤维-基体几乎完全脆性断裂。所提出的动态剪切试验方法有望测试两种材料或相之间界面的剪切行为,而破坏模式的转变是加载速率对CF/EP界面剪切行为影响的结果。




来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveSystemHPCInspire振动疲劳断裂复合材料非线性化学拓扑优化通用航空航天汽车建筑裂纹理论
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【新文速递】2024年8月12日复合材料SCI期刊最新文章

今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 1 篇Composite StructuresBlast resistance of 3D-printed Bouligand concrete panels reinforced with steel fibers: Numerical investigationsVuong Nguyen-Van, Phuong Tran, Ngoc San Ha, Yi Min Xie, Farhad Aslanidoi:10.1016/j.compstruct.2024.118481钢纤维增强3d打印Bouligand混凝土板的抗爆性能:数值研究3D-printed concrete structures inspired by Bouligand architecture with helically twisted sequences exhibit excellent mechanical performance owing to its aligned fiber orientation. In this study, 3D-printed concrete panels with different numbers of layers (five, ten, and 15 layers) and spiral angles (0°, 15°, 30°, and 45°) are designed for numerical investigations of their blast-resistant capacity. A multi-scale model is developed to capture the isotropic and anisotropic properties of the fiber-concrete composite. The adequacy and accuracy of the model are evaluated and validated by experimental data in the literature. Blast resistance of different types of panels in terms of time histories of central-point deflection, contact explosion-induced plastic dissipation energy, stress propagation, and principal stress distribution is examined. It is found that extrusion-based concrete panels with aligned fiber orientation substantially enhance the blast resistance compared to traditional cast concrete panels with random fiber orientation. Furthermore, more layers of printed concrete panels prove to be more efficient in filtering blast waves. In particular, shifting a pitch angle of 30° after printing each layer plays an important role in reducing the maximum deflection. Meanwhile, 3D-printed concrete panels with a pitch angle of 0° can better mitigate blast-induced damage. Through parametric studies, the intrinsic mechanism of steel fibers aligned in 3D-printed panels is numerically analyzed to support the conclusions.受Bouligand建筑的启发,具有螺旋扭曲序列的3d打印混凝土结构由于其排列的纤维取向而表现出优异的机械性能。在本研究中,设计了不同层数(5层、10层和15层)和螺旋角(0°、15°、30°和45°)的3d打印混凝土面板,对其抗爆能力进行了数值研究。建立了一种多尺度模型来捕捉纤维-混凝土复合材料的各向同性和各向异性特性。通过文献中的实验数据对模型的充分性和准确性进行了评价和验证。从中心点挠度、接触爆致塑性耗散能、应力传播和主应力分布等方面考察了不同类型板的抗爆性能。研究发现,纤维取向排列的挤压基混凝土板的抗爆性能明显优于纤维取向不规则的传统浇筑混凝土板。此外,多层印刷混凝土板被证明在过滤冲击波方面更有效。特别是,在打印每层后移动30°的俯仰角对减少最大挠度起着重要作用。同时,3d打印的0°俯仰角混凝土板可以更好地减轻爆炸引起的损伤。通过参数化研究,对钢纤维在3d打印板中排列的内在机理进行了数值分析,以支持上述结论。Composites Part A: Applied Science and ManufacturingA simulation strategy for fatigue modeling of delamination in composite structures under multiple loading conditions considering loading history and R -curve effectsI. Lecinana, L. Carreras, J. Renart, J. Zurbitu, B.H.A.H. Tijs, A. Turondoi:10.1016/j.compositesa.2024.108402 考虑加载历史和R曲线效应的复合材料结构分层疲劳建模仿真策略This work evaluates the ability of cohesive zone modeling-based approaches to predict delamination in composite materials that develop large process zones under complex loading conditions. The R -curve effects subjected to static and fatigue loading under multiple loading modes, considering the loading history, are analyzed. To this end, the delamination predictions of a state-of-the-art CZM-based simulation strategy are evaluated by blind simulation of a validation benchmark test. The validation test promotes a non-self-similar delamination scenario, including a process zone that evolves under different loading mode conditions with a non-straight leading delamination front. Good delamination prediction accuracy is achieved. In addition, insights into the relationship between the features of the simulation strategy and the physics of the delamination process are discussed. With regard to the limitations of the simulation strategy, particular attention should be paid to modeling the contribution of an evolving process zone based on the loading mode history.这项工作评估了基于内聚区建模的方法预测复合材料在复杂载荷条件下形成大工艺区的分层的能力。考虑载荷历史,分析了多种载荷模式下静载荷和疲劳载荷作用下的R曲线效应。为此,通过验证基准测试的盲模拟来评估最先进的基于czm的仿真策略的分层预测。验证测试促进了一个非自相似的分层场景,包括一个在不同负载模式条件下发展的过程区,该过程区具有一个非直的领先分层前沿。得到了较好的分层预测精度。此外,还讨论了模拟策略的特征与分层过程的物理特性之间的关系。考虑到仿真策略的局限性,应特别注意基于加载模式历史对不断发展的过程区域的贡献进行建模。Composites Part B: EngineeringMaterials design using genetic algorithms informed by convolutional neural networks: Application to carbon nanotube bundlesKaren J. DeMille, Riley Hall, Joshua R. Leigh, Ibrahim Guven, Ashley D. Speardoi:10.1016/j.compositesb.2024.111751 利用卷积神经网络的遗传算法设计材料:应用于碳纳米管束Carbon nanotube (CNT) composites are a promising but complex material system whose mechanical response is influenced by many features, including CNT bundle microstructures. It is intractable to design CNT bundle microstructures using experiments and/or simulations alone. Thus, we implement a machine learning-based tool comprising a genetic algorithm (GA) (which aids in selecting features for bundle microstructures) and a convolutional neural network (CNN) (which rapidly predicts mechanical performance of bundle microstructures). Training data for the CNN are obtained from micromechanical finite element simulations. CNN predictions achieve R2>0.96 for elastic and shear moduli and R2>0.83 for Poisson’s ratios. Microstructures identified by the CNN-informed GA outperform between 79% and 100% of solutions found using a brute-force search and in less than 5% of the time, providing an efficient tool for informed materials design of CNT bundle microstructures.碳纳米管(CNT)复合材料是一种前景广阔但结构复杂的材料系统,其机械响应受许多特征的影响,包括碳纳米管束微结构。仅靠实验和/或模拟来设计碳纳米管束微结构是难以实现的。因此,我们采用了一种基于机器学习的工具,包括遗传算法(GA)(帮助选择管束微结构的特征)和卷积神经网络(CNN)(快速预测管束微结构的机械性能)。CNN 的训练数据来自微机械有限元模拟。CNN 预测的弹性模量和剪切模量的 R2>0.96,泊松比的 R2>0.83。在不到 5%的时间内,CNN-informed GA 所确定的微结构优于 79% 至 100% 的使用蛮力搜索找到的解决方案,为 CNT 束微结构的知情材料设计提供了有效的工具。Strain sensing of structural composites by integrated piezoresistive CNT yarn sensorsMoisés Zarzoso, Anastasiia Mikhalchan, Davide Mocerino, Pablo Romero-Rodriguez, Ricardo Losada, Juan J. Vilatela, Carlos Gonzálezdoi:10.1016/j.compositesb.2024.111752集成压阻式碳纳米管纱线传感器的结构复合材料应变传感This work presents the development of piezoresistive strain sensors for the next-generation airframe parts. The sensors consist of polyetherketoneketone (PEKK) coated thermoplastic filaments with a continuous carbon nanotube (CNT) yarn reinforcement fully integrated into the structural thermoplastic CFRP laminates. PEKK coating improves the piezoresistive behaviour of CNT yarns by increasing internal stress transfer. When consolidated in a laminate, the CNT sensors have a gauge factor of 10.5 and 12 for 0.2% tensile and compressive deformations, respectively. The CNT sensors were calibrated and compared with commercial strain gauges at the coupon level and demonstrated high sensitivity in three- and four-point bend tests.本工作介绍了用于下一代机体部件的压阻式应变传感器的发展。传感器由聚醚酮酮(PEKK)涂层热塑性长丝和连续碳纳米管(CNT)纱线组成,完全集成到结构热塑性CFRP层压板中。PEKK涂层通过增加内应力传递来改善碳纳米管纱线的压阻性能。当在层压板中固化时,碳纳米管传感器对于0.2%的拉伸和压缩变形分别具有10.5和12的测量因子。对碳纳米管传感器进行了校准,并与商用应变片进行了对比,在三点和四点弯曲测试中显示出高灵敏度。Ultrahigh nitrogen-doped carbon derived from g-C3N4 assisted by citric acid for superior potassium-ion storageShasha Wang, Yuli Wei, Rongzhe Wang, Qing Liu, Qing Wang, Shaohua Luo, Yahui Zhang, Shengxue Yan, Pengqing Hou, Xin Liu, Jing Guo, Wenning Mudoi:10.1016/j.compositesb.2024.111759 柠檬酸辅助下由g-C3N4衍生的超高氮掺杂碳具有优异的钾离子储存性能Nitrogen-doped carbon is regarded as a promising anode for potassium ion batteries (PIBs) because nitrogen atoms can regulate the structures of carbon and generate abundant active sites. How to improve the nitrogen content in carbon through simple and effective methods remains to be further addressed. In this paper, a carbon material (60NC) with ultrahigh nitrogen content (16%) was prepared from graphite phase carbon nitride (g-C3N4) by a convenient freeze-drying and high-temperature pyrolysis method, assisted by citric acid. When used as an anode for PIBs, 60NC exhibited a superior reversible capacity of 318.1 mAh g-1 after 200 cycles at 0.1 A g-1. Even at the high current density of 1A g-1, 60NC maintained a specific capacity of 261.8 mAh g-1 after 1000 cycles. The excellent electrochemical performance of 60NC mainly stems from its abundant K+ storage active sites caused by nitrogen doping, large layer spacing, and hierarchical porous structure.氮掺杂碳由于可以调节碳的结构并产生丰富的活性位点而被认为是一种很有前途的钾离子电池阳极。如何通过简单有效的方法提高碳中氮的含量还有待进一步研究。本文以石墨相氮化碳(g-C3N4)为原料,在柠檬酸的辅助下,采用简便的冷冻干燥和高温热解法制备了超高氮含量(16%)的碳材料(60NC)。当用作pib的阳极时,60NC在0.1 a g-1下循环200次后表现出优异的318.1 mAh g-1的可逆容量。即使在1A g-1的高电流密度下,60NC在1000次循环后仍保持261.8 mAh g-1的比容量。60NC优异的电化学性能主要源于氮掺杂导致的丰富的K+存储活性位点、大的层间距和层次化的多孔结构。Designing vanadium-based nanoflower precursor towards improved Na3V2(PO4)3 cathode of sodium-ion batteriesZhenghao Wang, Liang Chen, Bin Liang, Xiaodong Guo, Zhenguo Wu, Dongmei Luodoi:10.1016/j.compositesb.2024.111762 改进钠离子电池正极Na3V2(PO4)3的钒基纳米花前驱体设计The sodium superionic conductor Na3V2(PO4)3 (NVP) is a promising cathode material for sodium-ion batteries due to its high energy density and efficient ion diffusion pathways. Nonetheless, the conventional solid-state reaction synthesis of NVP suffers from limitations such as a small surface area, irregular shape, and suboptimal electrochemical properties. To address these challenges, a two-step approach is masterfully designed in this study, commencing with the modulation of the morphology of vanadium-based precursor through chemical precipitation. Subsequently, the uniform carbon-coated porous NVP@C composite with a significantly enhanced specific surface area of 83.22 m2 g-1 is devised through the solid-state reaction. Compared to traditional precipitation methods producing VO(OH)2 from VOSO4 solution, which have low efficiency and uneven precursor formation, adding cetyltrimethylammonium bromide (CTAB) as a surfactant enhanced vanadium precipitation (99.9%) and yielded uniform nanoflower-shaped precursor with a large surface area. Remarkably, the synthesized NVP@C composite achieved an impressive reversible capacity of 87.7 mA h g-1 at a challenging 5 C rate, with 80.0% capacity retention after 1000 cycles. These findings highlight the ability to control precursor morphology and enhance surface area contributes significantly to the favorable properties and electrochemical performance of the resulting materials, promoting their viability for advanced energy storage applications.钠离子导体Na3V2(PO4)3 (NVP)具有高能量密度和高效的离子扩散途径,是一种很有前途的钠离子电池正极材料。然而,传统的固相反应合成NVP存在表面积小、形状不规则、电化学性能欠佳等局限性。为了解决这些挑战,本研究巧妙地设计了两步方法,首先通过化学沉淀法调制钒基前驱体的形态。随后,通过固相反应设计出均匀的碳包覆多孔NVP@C复合材料,其比表面积显著提高至83.22 m2 g-1。针对传统沉淀法从VOSO4溶液中生成VO(OH)2效率低且前驱体形成不均匀的问题,添加十六烷基三甲基溴化铵(CTAB)作为表面活性剂可提高钒的析出率(99.9%),并获得均匀且表面积大的纳米花状前驱体。值得注意的是,合成的NVP@C复合材料在具有挑战性的5℃温度下获得了令人印象深刻的87.7 mA h g-1可逆容量,1000次循环后容量保持率为80.0%。这些发现强调了控制前驱体形态和增加表面面积的能力,对所得材料的良好性能和电化学性能有重要贡献,促进了它们在先进储能应用中的可行性。Composites Science and TechnologyDegradation kinetics of PLA/hemp biocomposites: tradeoff between nucleating action and pro-hydrolytic effect of natural fibersLibera Vitiello, Sabrina Carola Carroccio, Veronica Ambrogi, Edoardo Podda, Giovanni Filippone, Martina Salzano de Lunadoi:10.1016/j.compscitech.2024.110806 聚乳酸/大 麻生物复合材料的降解动力学:天然纤维成核作用和促水解作用之间的权衡Natural fibers are not only a sustainable alternative to synthetic reinforcement materials, but can also be used to produce truly sustainable biocomposites with fast degradation kinetics. Indeed, due to their hygroscopicity, lignocellulosic fibers allow water and/or degrading organisms from the external environment to penetrate inside the host matrix and trigger its hydrolysis. The latter is the rate-limiting step for the degradation of bio-polyesters, which exhibit unacceptably slow degradation kinetics at ambient temperature and humidity. However, fibers also promote crystallization of the host matrix and thus slow down its degradation kinetics. To better understand and potentially control the degradation kinetics of biocomposites, here we investigate the ability of hemp shives, a hygroscopic by-product of hemp fiber production, to accelerate the hydrolysis of poly(lactic acid) (PLA). The degradation kinetics and degree of crystallinity of PLA are monitored in water and mature compost as a function of fiber content, which was varied across the percolation threshold (Φc) to study the effect of fiber interconnectivity. Above Φc, the fibers accelerate PLA hydrolysis in water despite their nucleating effect. Conversely, in compost the shielding effect of fiber-induced crystallinity prevails, and the fibers eventually slow down the degradation kinetics of PLA.天然纤维不仅是合成增强材料的可持续替代品,而且还可以用于生产具有快速降解动力学的真正可持续的生物复合材料。事实上,由于其吸湿性,木质纤维素纤维允许外部环境中的水和/或降解生物渗透到宿主基质内部并触发其水解。后者是生物聚酯降解的限速步骤,在环境温度和湿度下,生物聚酯表现出不可接受的缓慢降解动力学。然而,纤维也促进宿主基质的结晶,从而减缓其降解动力学。为了更好地理解和潜在地控制生物复合材料的降解动力学,我们研究了大 麻纤维生产的吸湿副产物大 麻片加速聚乳酸(PLA)水解的能力。通过监测PLA在水中和成熟堆肥中的降解动力学和结晶度作为纤维含量的函数,纤维含量随渗透阈值(Φc)的变化而变化,以研究纤维互联性的影响。在Φc上面,尽管纤维具有成核作用,但它们加速了PLA在水中的水解。相反,在堆肥中,纤维诱导结晶度的屏蔽效应盛行,纤维最终减缓了PLA的降解动力学。来源:复合材料力学仿真Composites FEM

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