今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 6 篇,Composites Part B: Engineering 3 篇
Analytical homogenization for equivalent in-plane elastic moduli of prestressed lattices based on the micropolar elasticity model
Zhi Guo, Xiang Liu, Li Huang, S. Adhikari, Xifeng Liang
doi:10.1016/j.compstruct.2024.118391
基于微极弹性模型的预应力网格等效面内弹性模量解析均匀化
Highly compressible and stretchable lattice materials have gained significant attention due to their advanced structural characteristics. However, most existing research on homogenization relies on linear classical elasticity theory, omitting nonlinear deformation and/or the micropolar elasticity rotation. This paper addresses this gap by introducing a novel analytical homogenization method for the in-plane equivalent elastic moduli of prestressed two-dimensional lattices that incorporates both nonlinear elastic deformation and micropolar elastic effects. First, the stiffness matrices of a lattice cell wall under axial force is formulated. Based on the micropolar elasticity theory, the micropolar elastic constitutive relations for four lattice materials under prestresses were established, i.e., rectangular, diamond, equilateral triangular, and mixed diamond lattices. Then, the micropolar elastic constants for different prestressed lattices are formulated. The closed-form expressions for the equivalent elastic moduli of nonlinear micropolar elastic bodies were derived from these micropolar elastic constants by their physical significance. The analytical expressions for the lattice elastic moduli are validated by using independent nonlinear finite element simulation in ANSYS with relative errors less than 4%. The proposed analytical method and new closed-form expressions provide a framework with high computational efficiency and accuracy for the analysis and parametric design of lattice materials under external stress.
高可压缩和高可拉伸晶格材料因其先进的结构特性而受到广泛关注。然而,现有的均匀化研究大多依赖于线性经典弹性理论,忽略了非线性变形和/或微极弹性旋转。本文通过引入一种新的二维预应力网格面内等效弹性模量的解析均匀化方法来解决这一空白,该方法同时考虑了非线性弹性变形和微极弹性效应。首先,建立了轴向力作用下晶格胞壁的刚度矩阵。基于微极弹性理论,建立了矩形、菱形、等边三角形和混合菱形四种晶格材料在预应力作用下的微极弹性本构关系。然后,给出了不同预应力格的微极弹性常数。根据这些微极弹性常数的物理意义,导出了非线性微极弹性体等效弹性模量的封闭表达式。通过ANSYS独立非线性有限元仿真,验证了晶格弹性模量解析表达式的正确性,相对误差小于4%。所提出的解析方法和新的封闭表达式为晶格材料在外加应力作用下的分析和参数化设计提供了一个计算效率高、精度高的框架。
Modified lap shear test for intralaminar shear failure of fiber reinforced composites
Malik John, John Park, Kedar Kirane
doi:10.1016/j.compositesa.2024.108368
纤维增强复合材料层间剪切破坏的改进搭接剪切试验
This work presents a modification of the lap shear test for application to the intralaminar shear failure of fiber reinforced composites. The proposed method involves an S-shaped double-cracked specimen loaded under uniaxial in-plane compression. The resulting loading is akin to a lap shear test but inducing intralaminar shear failure (not interlaminar). Elastic stress analysis confirms a shear dominated stress state in specimen ligament, and numerical contour-integral confirms a mode II dominance in the near tip region. Experimental results for an epoxy/carbon twill woven composite are presented, demonstrating the ease of the test method. Nonlinear quasi-ductile behavior is observed, as expected, and necessitates the use of elastoplastic fracture mechanics to interpret the fracture toughness. The estimated initiation toughness values are successfully verified via cohesive crack simulations. The presented test represents a simple and repeatable method to characterize the intralaminar shear failure of fiber-reinforced composites.
提出了一种适用于纤维增强复合材料层间剪切破坏的搭接剪切试验的改进方法。所提出的方法涉及一个s形双裂纹试件,在单轴面内压缩下加载。由此产生的荷载类似于搭接剪切试验,但会引起层内剪切破坏(而不是层间)。弹性应力分析证实了试样韧带的剪切主导应力状态,数值轮廓积分证实了近尖端区域的II型主导应力状态。最后给出了环氧/碳斜纹织物复合材料的实验结果,证明了该测试方法的可行性。正如预期的那样,观察到非线性准延性行为,需要使用弹塑性断裂力学来解释断裂韧性。通过内聚裂纹模拟成功验证了估算的起裂韧性值。本试验为表征纤维增强复合材料层间剪切破坏提供了一种简单、可重复的方法。
Copper oxide decorated one-dimensional mineral nanorods: Construction of strengthened gas-phase and condensed-phase coupled intumescent flame retardant
Zeyang Gao, Yu Zhu, Xiaoyong Liu, Bihe Yuan, Ranzhao Shen, Kailin Li, Yao Yin, Zhipeng Zhang
doi:10.1016/j.compositesa.2024.108373
氧化铜修饰一维矿物纳米棒:强化气相-冷凝相耦合膨胀阻燃剂的构建
Polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) features superior mechanical properties but suffers from high flammability, presenting a grand challenge in enhancing its flame retardancy with halogen-free additives. Herein, we developed an efficient flame-retardant system (BH/CuATP) by incorporating phosphazene additive (HP), copper oxide modified attapulgite (CuATP) and bisphenol A bis (diphenyl phosphate) (BDP). This system achieves a UL-94V-0 rating without melt-dripping and leads to reductions in the peak heat release rate (43.1 %), total heat release (29.8 %) and total smoke production (5.7 %). The strength effect of CuATP in both gas-phase and condensed-phase significantly contributes to its enhanced fire safety. Additionally, the mechanical properties of PC/ABS/B1H1/CuATP1 are improved due to the rod-like CuATP, showing enhanced comprehensive properties superior to other reported systems. This work presents valuable insights into the effectiveness of mineral-strength intumescent flame retardancy for PC/ABS, offering practical guidance for the development of high-performance PC/ABS composites.
聚碳酸酯/丙烯腈-丁二烯-苯乙烯(PC/ABS)具有优异的机械性能,但具有较高的可燃性,使用无卤添加剂增强其阻燃性是一个巨大的挑战。本文采用磷腈添加剂(HP)、氧化铜改性凹凸棒土(CuATP)和双酚A双(二苯基磷酸)(BDP)为原料,研制了一种高效阻燃体系(BH/CuATP)。该系统达到UL-94V-0等级,无熔滴,并导致峰值放热率(43.1% %),总放热率(29.8% %)和总烟雾产量(5.7% %)的降低。CuATP在气相和冷凝相中的强度效应显著提高了其防火安全性。此外,由于棒状CuATP的存在,PC/ABS/B1H1/CuATP1的力学性能得到了改善,其综合性能优于其他已报道的体系。本工作对PC/ABS矿物强度膨胀阻燃的有效性提出了有价值的见解,为高性能PC/ABS复合材料的开发提供了实践指导。
Developing an efficient analytical model for predicting the electrical conductivity of polymeric nanocomposites containing hybrid carbon nanotube/carbon black nanofillers
Maedeh Saberi, Alireza Moradi, Reza Ansari, Mohammad Kazem Hassanzadeh-Aghdam, Jamaloddin Jamali
doi:10.1016/j.compositesa.2024.108374
建立了一种预测含碳纳米管/炭黑纳米填料的聚合物纳米复合材料电导率的有效分析模型
Inter-cluster bridging of carbon nanotubes (CNTs) and carbon black (CB) nanoparticles conjoins inactive branches of carbonaceous nanofillers within the matrix and reduces the electron tunneling distance. This mechanism moderately overcomes quantum tunneling and provides percolative polymer networks exhibiting favorable electrical responses. This study focuses on devising an analytical procedure to scrutinize the electrical conductivity and percolation threshold of CNT/CB/polymer nanocomposites. To involve the physics of electrical processes, the modeling approach considers cylindrical CNTs and spherical CB nanoparticles surrounded by a continuum interphase, which serves as an electron hopping duct. This model is extended in a bottom-up micromechanics generalization to a level where it is capable of predicting the effects of a wide range of microstructural properties. The comparison of predictions with those obtained via experimental examinations, while affirming the infrastructure for investigating the electrical behavior of binary systems, convincingly captures the electrical conductivity/percolation threshold of ternary nanocomposites containing CNT/CB nanofillers.
碳纳米管(CNTs)和炭黑(CB)纳米颗粒簇间桥接连接了基体内碳基纳米填料的非活性分支,减少了电子隧穿距离。这种机制适度地克服了量子隧道效应,并提供了具有良好电响应的渗透聚合物网络。本研究的重点是设计一种分析程序来仔细检查碳纳米管/碳炭黑/聚合物纳米复合材料的电导率和渗透阈值。为了涉及电过程的物理学,建模方法考虑了圆柱形碳纳米管和球形碳纳米管,它们被一个连续的界面所包围,作为一个电子跳跃管道。该模型在自下而上的微观力学推广中扩展到能够预测各种微观结构特性的影响的水平。将预测结果与实验结果进行比较,确定了研究二元体系电学行为的基础设施,并令人信服地捕获了含有碳纳米管/碳纳米管纳米填料的三元纳米复合材料的电导率/渗透阈值。
Regulating the bimodal structure and strength-ductility synergy of Zn-decorated Ti particles reinforced AZ91 composite through high-volume fraction Mg17Al12 precipitations
Yuhui Zhang, Shengli Han, Pengfei Gao, Pengju Chen, Jun Xia, Jianbo Li, Jia She, Xianhua Chen, Kaihong Zheng, Fusheng Pan
doi:10.1016/j.compositesa.2024.108376
通过高体积分数Mg17Al12析出调节zn修饰Ti颗粒增强AZ91复合材料的双峰结构和强度-塑性协同作用
In this work, Mg-9Al-1Zn (AZ91) alloy reinforced with zinc-decorated titanium (Zn@Ti) particles was fabricated using the powder metallurgy method. Zn nanoparticles effectively dissolved into magnesium (Mg) matrix, which led to a reduction in the solid solubility of aluminum (Al) and precipitations of submicron sized Mg17Al12. As a result, the Zn@Ti/AZ91 composite displays a bimodal grain structure, achieving a remarkable balance between strength and ductility, with a yield strength of 248 ± 3.5 MPa, an ultimate tensile strength of 378 ± 5.3 MPa, and an elongation of 15.0 ± 2.8 %. The improved strength of Zn@Ti/AZ91 composite primarily stems from the synergistic effect of a significant volume fraction of submicron sized Mg17Al12 and Al8Mn5 precipitations strengthening, Zn solid solution strengthening, and grain boundary strengthening. Regarding ductility mechanisms, the presence of Mg17Al12 and Al8Mn5 precipitations effectively impede crack propagation and enhance ductility. This innovative approach represents a promising strategy for developing high strength and ductility of Mg composites.
本文采用粉末冶金方法制备了锌修饰钛(Zn@Ti)颗粒增强Mg-9Al-1Zn (AZ91)合金。锌纳米粒子有效地溶解在镁基体中,导致铝的固溶性降低,亚微米级Mg17Al12析出。因此,Zn@Ti / AZ91复合显示双峰晶粒结构,实现非凡的强度和延性之间的平衡,屈服强度248 ±3.5 MPa,极限抗拉强度378 ±5.3 MPa,和15.0的伸长 ±2.8 %。Zn@Ti/AZ91复合材料强度的提高主要源于大量体积分数的亚微米级Mg17Al12和Al8Mn5析出强化、Zn固溶体强化和晶界强化的协同作用。在延性机制方面,Mg17Al12和Al8Mn5析出物的存在有效地阻碍了裂纹扩展,增强了延性。这种创新的方法代表了开发高强度和高塑性镁复合材料的一种有前途的策略。
Experimental investigation on microstructure, mechanical and optical properties of RB-SiC ablated by nanosecond pulsed laser in nitrogen atmosphere
Hong An, Yongfeng Qian, Zhiyu Zhang, Hu Huang, Jiwang Yan
doi:10.1016/j.compositesa.2024.108377
氮气氛下纳秒脉冲激光烧蚀RB-SiC的显微组织、力学和光学性能的实验研究
Reaction-bonded silicon carbide (RB-SiC) has gained significant attention owing to its exceptional physical and chemical properties. Improving the photovoltaic efficiency and mechanical properties of RB-SiC is conducive to further enhancing its applicability. Laser gas nitriding is an effective strategy to simultaneously reduce the surface reflectivity and enhance the surface hardness of materials. Accordingly, the evolution of microstructure, mechanical and optical properties of RB-SiC composite ablated by nanosecond pulsed laser in nitrogen atmosphere was comprehensively investigated. After laser gas nitriding, the surface hardness of RB-SiC composite was increased by 10.6–44.6 %. The chemical composition analysis indicated that Si-based nitride was formed on the laser-ablated surface, which was mainly responsible for the hardness enhancement. Additionally, the reflectivity of the laser-ablated surface was reduced by up to 95.2 % compared to the original RB-SiC composite. This study provides a straightforward and effective method to simultaneously improve the mechanical and optical properties of RB-SiC composites.
反应键合碳化硅(RB-SiC)由于其优异的物理和化学性能而受到广泛关注。提高RB-SiC的光伏效率和力学性能有利于进一步增强其适用性。激 光气体氮化是降低材料表面反射率、提高材料表面硬度的有效方法。在此基础上,对纳秒脉冲激光在氮气气氛下烧蚀RB-SiC复合材料的显微组织、力学性能和光学性能的演变进行了全面研究。激光 气体氮化后,RB-SiC复合材料的表面硬度提高了10.6 ~ 44.6% %。化学成分分析表明,激光烧蚀表面形成了硅基氮化物,这是硬度增强的主要原因。此外,激光烧蚀表面的反射率比原始RB-SiC复合材料降低了95.2% %。本研究为同时提高RB-SiC复合材料的力学性能和光学性能提供了一种简单有效的方法。
Data-driven thermal modeling of in-situ Automated Fiber Placement
Allyson Fontes, Farjad Shadmehri
doi:10.1016/j.compositesa.2024.108379
原位自动铺放纤维的数据驱动热建模
This study proposes a data-driven model for thermal history prediction during in-situ Automated Fiber Placement of thermoplastic composites. Temperature data was experimentally collected with fast-response thermocouples placed within carbon fiber AS4/PEEK composite substrates. The temperature for various combinations of hot gas torch temperatures, heat source velocity, and locations through the thickness and width were collected. A feedforward neural network (FNN) was developed to predict the entire 3-dimensional thermal history. The FNN had five input features and one output: the temperature at a given position and a combination of the process parameters. The FNN predictions for data unseen during training are validated for cases of interpolation and extrapolation. As expected, suitable performance was obtained for cases of interpolation, but predictions suffered in extrapolation. The computational efficiency of FNNs makes them an appropriate candidate for on-line thermal history prediction or process optimization, given that they are used within their training range
本研究提出了一种数据驱动模型,用于热塑性复合材料原位自动铺放纤维过程中的热历史预测。温度数据通过放置在碳纤维AS4/PEEK复合材料衬底内的快速响应热电偶进行实验采集。收集了不同温度组合下的温度、热源速度以及不同厚度和宽度下的位置。提出了一种前馈神经网络(FNN)来预测整个三维热历史。FNN有五个输入特征和一个输出特征:给定位置的温度和过程参数的组合。FNN对训练期间未见数据的预测在插值和外推的情况下得到验证。正如预期的那样,在插值的情况下获得了合适的性能,但外推的预测受到影响。fnn的计算效率使其成为在线热历史预测或过程优化的合适候选者,因为它们在其训练范围内使用
Applications of Artificial Intelligence/Machine Learning to High-Performance Composites
Yifeng Wang, Kan Wang, Chuck Zhang
doi:10.1016/j.compositesb.2024.111740
人工智能/机器学习在高性能复合材料中的应用
With the booming prosperity of artificial intelligence (AI) technology, it triggers a paradigm shift in engineering fields including material science. The integration of AI and machine learning (ML) techniques in material science brings significant advancements in understanding and characterizing underlying physics. Due to the overall outstanding properties compared to conventional metallic materials, high-performance fiber reinforced polymer (FRP) composites have attracted great interest. This article aims to provide a comprehensive review of the state-of-the-art works of applying AI/ML methods in high-performance FRP composites, focusing on four critical stages throughout the product life cycle, i.e., design, manufacturing, testing, and monitoring. This present study covers the tasks of material development and selection, process modeling and optimization, material property prediction, and damage diagnosis and prognosis in the four stages, which are conducted with the aid of advanced AI/ML algorithms. An outlook for the incorporation of modern advanced AI/ML models into FRP composite research is provided by the identification of current challenges and potential future research directions.
随着人工智能(AI)技术的蓬勃发展,引发了包括材料科学在内的工程领域的范式转变。人工智能和机器学习(ML)技术在材料科学中的整合,在理解和表征基础物理方面取得了重大进展。由于与传统金属材料相比,高性能纤维增强聚合物(FRP)复合材料的整体性能突出,引起了人们的极大兴趣。本文旨在全面回顾在高性能FRP复合材料中应用AI/ML方法的最新工作,重点关注整个产品生命周期的四个关键阶段,即设计、制造、测试和监控。本研究采用先进的AI/ML算法,完成了材料开发与选择、工艺建模与优化、材料性能预测、损伤诊断与预测四个阶段的工作。通过确定当前的挑战和潜在的未来研究方向,展望了将现代先进的AI/ML模型纳入FRP复合材料研究的前景。
Based on the preparation of dual-absorber agents using Ni and Ni/rGO for the fabrication of a dual honeycomb nested structure for wideband microwave absorption
Shaokang Liu, Fangxin Zhang, Bin Chao, Wenxin Fu, Kaixin Deng, Yan Li, Haihua Wu
doi:10.1016/j.compositesb.2024.111735
本文在制备双吸收剂的基础上,利用Ni和Ni/rGO制备了用于宽带微波吸收的双蜂窝嵌套结构
Designing absorbers with structural support to achieve ultra-wideband and wide-angle absorption properties is crucial for addressing the growing concern of electromagnetic pollution. In this study, a strategy is proposed to further broaden the bandwidth of structural absorbers by applying different materials to different structures and then nesting these different structures. Six composite materials were prepared using Ni and rGO as absorbers, and a dual honeycomb nested structure was fabricated using 3D printing technology. The minimum reflection loss (RL) of the two types of composite materials was −19.3 dB and −15.8 dB, respectively, with effective absorption bandwidths (EAB) of 4.6 GHz and 4.4 GHz, demonstrating mechanical compatibility and electromagnetic substitutability. The dual honeycomb nested structure utilized a multiscale design approach, achieving broadband absorption up to 14.27 GHz and compressive strength of 5.92 MPa. Furthermore, stable frequency response of transverse electric (TE) waves was observed within an incident angle range of 0°–40°, while absorption frequencies exceeded 12 GHz as transverse magnetic (TM) waves incident angle varied from 0° to 60°, highlighting wide-angle absorption characteristics. The dual composite preparation strategy of materials and structures for absorber fabrication provides a new perspective for further expanding the bandwidth of absorbers.
设计具有结构支撑的吸波器以实现超宽带广角吸收特性是解决日益受到关注的电磁污染问题的关键。本研究提出了一种策略,通过将不同的材料应用于不同的结构,然后将这些不同的结构嵌套,进一步拓宽结构吸收器的带宽。以Ni和还原氧化石墨烯为吸波剂制备了6种复合材料,并利用3D打印技术制备了双蜂窝嵌套结构。两种复合材料的最小反射损耗(RL)分别为- 19.3 dB和- 15.8 dB,有效吸收带宽(EAB)分别为4.6 GHz和4.4 GHz,具有良好的机械相容性和电磁可替代性。双蜂窝嵌套结构采用多尺度设计方法,实现了高达14.27 GHz的宽带吸收和5.92 MPa的抗压强度。此外,在0°~ 40°入射角范围内,横电波的频率响应稳定,而横磁波在0°~ 60°入射角范围内,吸收频率超过12 GHz,显示出广角吸收特征。材料和结构的双重复合制备策略为进一步扩大吸波器的带宽提供了新的前景。
Multi-Objective Optimization Through Desirability Function Analysis on the Crashworthiness Performance of Thermoplastic/Thermoset Hybrid Structures
Mahmoud M. Awd Allah, Marwa A. Abd El-baky
doi:10.1016/j.compositesb.2024.111742
基于期望函数分析的热塑性/热固性混合结构耐撞性能多目标优化
This paper aims to optimize the crashworthiness capability of glass-reinforced epoxy composites (GFRE) over wrapped polyvinyl chloride (PVC) circular tubes with cutouts. The intended tubes were prepared by a wet wrapping method; then subjected to quasi-static axial compression. To compute crashworthiness indications, three design parameters, each at three levels, were used. The design parameters are the hole diameter (d), the hole’s number (n), and the hole position (L). A few runs were accompanied by the L9 orthogonal array based on the Taguchi technique. With the lowest initial peak crash force () and the largest absorbed energy (U), the optimal parameters were found. Furthermore, the main effect, signal-to-noise ratio (S/N), as well as the analysis of variance (ANOVA), have been studied using the commercial software program MINITAB 18. Furthermore, to optimize the process parameters in terms of the crashworthiness indicators, desirability function analysis (DFA) was applied. Lastly, tests for confirmation were performed to verify the predicted values in light of the experimental results and compare them with the intact tubes. Regarding the single optimization, the optimum tube is smaller than the intact PVC tube and intact hybrid tube, at 24.01 and 72.85%, respectively. Nonetheless, the optimal U was 21.43% lower than the intact hybrid tube and 152.75% greater than the intact PVC tube. While, for and U, the multi-objective optimization specimen achieves 5.13 and 70.02% greater than the intact PVC tube. But it was 62.44% and 47.14% less than what the intact hybrid tube had accomplished.
本文旨在优化玻璃增强环氧复合材料(gfr)覆盖有切口的聚氯乙烯(PVC)圆管的耐撞性能。所述管采用湿包膜法制备;然后进行准静态轴向压缩。为了计算耐撞性指标,使用了三个设计参数,每个参数在三个级别上。设计参数为孔直径(d)、孔数(n)和孔位置(L)。少量井眼采用基于田口技术的L9正交阵列。以最小的初始峰值碰撞力()和最大的吸收能量(U)为最优参数。此外,利用商业软件MINITAB 18对主效应、信噪比(S/N)以及方差分析(ANOVA)进行了研究。在此基础上,应用理想函数分析(DFA)方法,从耐撞性指标出发对工艺参数进行优化。最后,根据实验结果对预测值进行了验证,并与完整管进行了对比。对于单次优化,最优管材比完整PVC管材和完整杂化管材小,分别为24.01和72.85%。最优U值比杂交管材整体低21.43%,比聚氯乙烯管材整体高152.75%。而对于和U,多目标优化试样比完整PVC管分别大5.13和70.02%。但与完整杂交管相比,分别降低了62.44%和47.14%。