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【新文速递】2024年1月15日复合材料SCI期刊最新文章

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今日更新:Composite Structures 4 篇,Composites Part A: Applied Science and Manufacturing 1 篇

Composite Structures

Vibration analysis of conical–cylindrical–spherical shells by a novel linear expression method

Wenjie Guo, Xian Hong, Wenjun Luo, Jian Yang, Tianyun Li, Xiang Zhu

doi:10.1016/j.compstruct.2024.117879

一种新的线性表达式法分析圆锥-圆柱-球形壳的振动

Composite shells are increasingly used in underwater vehicles, aerospace and other engineering fields. In this study, a linear expression method (LEM) was developed for the efficient vibration analysis of conical–cylindrical–spherical shell structures. Herein, the constraint and continuity conditions were expressed in matrix form, and a full-rank matrix was derived via the Gaussian elimination method. Then, it was possible to linearly express the unknown coefficients in the original equations. Consequently, combined with the energy method, the vibration characteristics of composite shells could be obtained. A conical–cylindrical–spherical shell was considered as an example. Its natural frequencies, vibration modes, and forced vibration analysis were carried out, and the results are compared for verification with those obtained by the finite element method (FEM) and those found in the literature. It is shown that the proposed LEM can be up to five times faster than FEM. Concentrated mass points and forced vibration were also considered, and the partial coupling between the shell and the mass points led to the breaking down of the circumferential symmetry of the cylindrical shell. The convergence of LEM is related only to the number of truncated terms of the shape functions; thus, it exhibits strong convergence and reduced computational cost, and offers a wide range of potential applications.

复合材料壳体在水下航行器、航空航天等工程领域的应用越来越广泛。本文提出了一种有效分析圆锥-圆柱-球壳结构振动的线性表达式法。其中,约束条件和连续性条件以矩阵形式表示,并通过高斯消去法推导出一个全秩矩阵。这样,就可以对原方程中的未知系数进行线性表示。因此,结合能量法可以得到复合材料壳的振动特性。以圆锥-圆柱-球形壳为例。对其固有频率、振型和受迫振动进行了分析,并与有限元法和文献结果进行了对比验证。结果表明,所提出的登月舱比有限元法的速度快5倍。考虑了集中质量点和强迫振动,壳与质量点之间的部分耦合导致圆柱壳的周向对称性被破坏。LEM的收敛性只与形状函数截断项的个数有关;因此,它具有较强的收敛性和较低的计算成本,具有广泛的潜在应用前景。


Modeling and Vibration Control of a Rotating Flexible Plate Actuated by MFC

Yongbin Guo, Yunxin Yu, Liang Li, Dingguo Zhang, Wei-Hsin Liao, Chaofan Du, Xian Guo

doi:10.1016/j.compstruct.2024.117907

MFC驱动旋转柔性板的建模与振动控制

The macro fiber composite (MFC) is a novel piezoelectric intelligent material, which is widely used in the field of vibration control due to its flexibility and larger actuation forces than PZT. In this paper, a laminated plate model considering the anisotropy of MFC is developed and applied to the vibration control of a rotating plate. The laminated plate is defined as a layerwise model, which deformation is described by the Absolute Nodal Coordinate Formulation (ANCF). The MFC laminated plate element contains 48 degrees of freedom (DOFs) where the effect of MFC element can be internally incorporated without increasing the DOFs of system. Simultaneously, a neural network PD control is adopted to control the vibration of the rotating plate. Eventually, static, dynamic, and modal analyses are performed to investigate the effects of different parameters. Several vibration simulations are carried out to illustrate the ability of MFC patches on vibration control. The findings in this article would be applied to mechanical prediction and control for rotor blades of helicopters, solar panels, etc.

宏纤维复合材料(MFC)是一种新型的压电智能材料,由于其柔性和比PZT更大的致动力而广泛应用于振动控制领域。本文建立了考虑MFC各向异性的层合板模型,并将其应用于旋转板的振动控制。将层合板定义为一种分层模型,其变形用绝对节点坐标公式(ANCF)来描述。MFC层合板单元包含48个自由度,在不增加系统自由度的情况下,可以将MFC单元的影响纳入系统内部。同时,采用神经网络PD控制对旋转盘的振动进行控制。最后,进行了静态、动态和模态分析,以研究不同参数的影响。通过几个振动仿真来说明MFC补丁在振动控制上的能力。本文的研究结果将应用于直升机旋翼叶片、太阳能板等的力学预测与控制。


Experimental and numerical investigations on the post-heating performance of concrete-filled pultruded GFRP tubes under concentric compression

Arian Mollakhalili, Mojtaba Tabatabaeian, Alireza Khaloo

doi:10.1016/j.compstruct.2024.117914

同心圆压缩下挤压玻璃钢混凝土填充管加热后性能的试验与数值研究

Concrete-filled FRP tubes are gaining popularity among structures in areas with harsh environmental conditions. Despite their unique properties, FRP materials have poor resistance to elevated temperatures. This paper presents experimental and numerical investigations on the post-heating performance of concrete-filled pultruded GFRP tubes under concentric compression. Specimens were tested with different tube thicknesses of 3, 5, and 7mm. The infill concrete was prepared with different compressive strengths of 30 and 60MPa. Also, samples were exposed to five temperatures of 25,100, 200, 300, and 400°C. Afterward, an axial compression test was conducted after the cooling process. The results indicated that the thickness of the tube was the most effective parameter in the axial load-bearing capacity of CFGFTs, while differences in the concrete’s compressive strength did not influence the results significantly. Furthermore, the results showed that as the exposure temperature increases, the axial load-bearing capacity of the specimens decreases consistently. In addition, the comparison between the peak load values obtained from experiments and previously proposed models (codes and literature) showed that predictions for externally bonded FRP systems underestimate the peak load-bearing capacity. Finally, it is concluded that the results obtained from finite element analysis were in good agreement with the experiments.

在环境条件恶劣的地区,FRP钢管在结构中越来越受欢迎。尽管具有独特的性能,但FRP材料对高温的耐受性较差。本文对挤压玻璃钢混凝土填充管在同心压缩下的热后性能进行了试验和数值研究。试件采用3、5、7mm不同管厚进行试验。配制抗压强度分别为30和60MPa的填充混凝土。此外,样品暴露在25,100,200,300和400°C的五种温度下。冷却后进行轴压试验。结果表明,钢管厚度是影响cfgft轴向承载力的最有效参数,而混凝土抗压强度的差异对结果影响不显著。结果表明,随着暴露温度的升高,试件的轴向承载力呈下降趋势。此外,从实验和先前提出的模型(规范和文献)中获得的峰值荷载值之间的比较表明,对外部粘结FRP系统的预测低估了峰值承载能力。最后,得出了有限元分析结果与试验结果吻合较好的结论。


An adaptive Ritz formulation for progressive damage modelling in variable angle tow composite plates

Dario Campagna, Vincenzo Oliveri, Ivano Benedetti

doi:10.1016/j.compstruct.2024.117915

变角度牵引复合材料板渐进损伤模型的自适应Ritz公式

In this work, an adaptive Ritz model for the analysis of variable angle tow composite plates featuring damage initiation and evolution under progressive loading is proposed, developed, implemented and tested. The plate kinematics is represented employing a first-order shear deformation theory, while the plate equilibrium equations at a given load step are obtained by minimising the structure potential energy. The constitutive behaviour is modelled within the framework of continuum damage mechanics. In particular the initiation and evolution of damage, up to failure, are tracked by defining irreversible damage indexes related to both fibres and matrix, both in tensile or compression loading. The discrete equations are then obtained by assuming a polynomial Ritz approximation of the primary kinematic variables in the energy minimisation. Preliminary tests show how the application of the method as a single-domain approach induces the emergence of problematic spurious effects, related to Gibbs artefacts due to the inability of the selected polynomial basis to represent damage localisation. An adaptive multi-domain technique is thus proposed to circumvent such issues, which has been successfully validated by benchmark tests. Eventually, original results about variable angle tow plates featuring damage evolution under progressive loading are presented.

在这项工作中,提出了一种自适应Ritz模型,用于分析变角拖曳复合材料板在递进载荷下的损伤起裂和演化。板的运动学采用一阶剪切变形理论来表示,而在给定的载荷步长下,通过最小化结构势能来获得板的平衡方程。在连续损伤力学的框架内对其本构行为进行了建模。特别是,通过定义与纤维和基体相关的不可逆损伤指数,在拉伸或压缩载荷下,跟踪损伤的开始和演变直至失效。然后通过假设能量最小化中主要运动变量的多项式里兹近似得到离散方程。初步测试表明,该方法作为单域方法的应用如何引起有问题的虚假效应的出现,这与Gibbs伪像有关,因为所选的多项式基无法表示损伤局部。为此,提出了一种自适应多域技术,并通过基准测试成功验证了该技术的有效性。最后,给出了变角拖曳板在递进载荷作用下损伤演化的原始结果。


Composites Part A: Applied Science and Manufacturing

A numerical multi-scale method for analyzing the rate-dependent and inelastic response of short fiber reinforced polymers: modeling framework and experimental validation

H. Ahmadi, M. Hajikazemi, D. Finazzi, Y. Sinchuk, W. Van Paepegem

doi:10.1016/j.compositesa.2024.108018

一种分析短纤维增强聚合物速率相关和非弹性响应的多尺度数值方法:建模框架和实验验证

This research presents a numerical multi-scale approach that efficiently addresses the inelastic and time-dependent mechanical response of short fiber reinforced polymers (SFRPs) under monotonic loading conditions by linking the mechanical analysis from microscale analysis to a continuum model. To do so, first, the mechanical performance of a recently suggested unit cell, considering the intrinsic mechanical characteristics of both fiber and matrix, is studied to address the inelastic and rate-dependent mechanical behavior of completely aligned SFRPs. Then, the evaluated mechanical response is linked to the Hill's plasticity and Two-Layer ViscoPlastic (TLVP) models to represent the anisotropic mechanical response of SFRPs. Furthermore, an easy-to-use multi-step homogenization process is considered to numerically incorporate the influence of fiber misalignments. Finally, the suggested multi-scale technique is thoroughly validated at different strain rates, by using experimental observations of short fiber composites with high volume fraction and direct FE simulations of RVEs with complex microstructures.

本研究提出了一种多尺度的数值方法,通过将力学分析从微观尺度连接到连续介质模型,有效地解决了短纤维增强聚合物(SFRPs)在单调加载条件下的非弹性和时变力学响应。为此,首先,考虑到纤维和基体的固有力学特性,研究了最近提出的单元胞的力学性能,以解决完全排列的SFRPs的非弹性和速率相关的力学行为。然后,将评估的力学响应与希尔塑性和双层粘塑性(TLVP)模型联系起来,以表示SFRPs的各向异性力学响应。此外,考虑了一种易于使用的多步均质过程,在数值上考虑了纤维错位的影响。最后,通过高体积分数短纤维复合材料的实验观察和复杂微观结构RVEs的直接有限元模拟,在不同应变速率下对所提出的多尺度技术进行了全面验证。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemDeform振动复合材料航空航天CONVERGE理论材料太阳能多尺度控制试验
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首次发布时间:2024-11-05
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【新文速递】2024年1月19日复合材料SCI期刊最新文章

今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 5 篇,Composites Science and Technology 1 篇Composite StructuresBending fatigue behaviour of internal replacement pipe systemsShanika Kiriella, Allan Manalo, Cam Minh Tri Tien, Hamid Ahmadi, Patrick G. Dixon, Warna Karunasena, Ahmad Salah, Brad P. Whamdoi:10.1016/j.compstruct.2024.117910内换管系统的弯曲疲劳特性Internal replacement pipe (IRP) systems are becoming an effective rehabilitation technique for legacy oil and gas pipelines with defects and discontinuities. Under repetitive traffic loads, the IRP-repaired pipes are subjected to fatigue. However, existing knowledge on the fatigue behaviour and remaining service life of IRP systems with circumferential discontinuities under cyclic bending is limited. Therefore, this paper investigated numerically the bending fatigue behaviour of legacy pipelines with circumferential discontinuities rehabilitated with IRP made from various material systems. The influence of the discontinuity width of the host pipe, thickness and elastic modulus of IRP, and level of traffic loading on the fatigue behaviour is evaluated. The results show that the tensile stress concentration at the discontinuity edge controls the bending fatigue behaviour of fully bonded IRP. The critical stresses and the minimum fatigue lifetimes are considerably influenced by the thickness and elastic modulus of the IRP systems, and the level of traffic loading while the width of the circumferential discontinuity has an insignificant effect. Multiple regression analyses show that the level of the traffic load has the most significant effect on the critical stress generated in the IRP, while the largest contribution to the minimum fatigue life comes from the elastic modulus of the repair material.内部替换管道(IRP)系统正在成为一种有效的修复技术,用于修复存在缺陷和不连续性的传统油气管道。在重复的流量载荷作用下,irp修复的管道会产生疲劳。然而,现有的关于具有周向不连续的IRP系统在循环弯曲下的疲劳行为和剩余使用寿命的知识是有限的。因此,本文对采用不同材料体系的IRP修复具有周向不连续的遗留管道的弯曲疲劳行为进行了数值研究。评估了主管不连续宽度、IRP厚度和弹性模量以及交通荷载水平对其疲劳行为的影响。结果表明,不连续边缘处的拉应力集中控制着全粘结IRP的弯曲疲劳行为。临界应力和最小疲劳寿命受IRP系统的厚度、弹性模量和交通荷载水平的显著影响,而周向不连续面宽度的影响不显著。多元回归分析表明,交通荷载水平对IRP产生的临界应力影响最显著,而修复材料的弹性模量对最小疲劳寿命的贡献最大。Mechanical Response of Carbon Fiber Reinforced Epoxy Composite Parts Joined with Varying Bonding Techniques for Aerospace ApplicationsFurkan Karaboğa, Fatih Göleç, Doruk Erdem Yunus, Serkan Toros, Yahya Özdoi:10.1016/j.compstruct.2024.117920航空航天用不同粘接技术的碳纤维增强环氧复合材料部件的力学响应As a result of the widespread use of composite materials in primary structures of aerospace platforms, composite joining became more crucial. This study addresses the effect of joining methods on the strength of composite joints experimentally, numerically and analytically. Single lap joint shear strengths of carbon fiber reinforced epoxy composite parts joined by mechanical fastening with a pop rivet and solid rivet, secondary bonding with a paste adhesive, co-curing and co-bonding techniques were compared. In addition, the effect of adhesive thicknesses (0.2, 0.4, 0.6, 0.76 mm) on the single lap shear strength was investigated. Carbon fiber reinforced composite (CFRP) samples were produced according to the ASTM 5868 standard. After the production of samples with varying joining methods, single lap shear tests were implemented. Moreover, the interface damage in composites was examined by use of a scanning electron microscope (SEM) for the purpose of studying the damage mechanism. Fracture mechanisms corresponding with bonding methods were also assessed by examining the fracture surface of the composite samples. Furthermore, results were analyzed by Hypermesh, ABAQUS and ESAComp. For instance, the co-bonded sample with an adhesive film exhibits an experimental shear strength of 24.03 MPa which deviates only 3 % from the numerical expectation.随着复合材料在航空航天平台初级结构中的广泛应用,复合材料连接变得更加关键。本文研究了不同连接方式对复合材料接头强度的影响。比较了流行铆钉与实钉机械紧固、粘贴胶二次粘接、共固化和共粘接碳纤维增强环氧复合材料零件的单搭接抗剪强度。此外,还研究了胶粘剂厚度(0.2、0.4、0.6、0.76 mm)对单次搭接抗剪强度的影响。碳纤维增强复合材料(CFRP)样品按ASTM 5868标准生产。在制作出不同连接方式的试件后,进行了单搭接剪切试验。利用扫描电子显微镜(SEM)对复合材料的界面损伤进行了研究。通过观察复合材料试样的断口形貌,对不同粘结方式下的断裂机制进行了评价。利用Hypermesh、ABAQUS和ESAComp对结果进行分析。例如,带胶膜的共粘结试样的实验抗剪强度为24.03 MPa,与数值预期偏差仅为3%。Enhanced mechanical properties of re-entrant auxetic honeycomb with self-similar inclusionZeyao Chen, Junhao Li, Baisheng Wu, Xin Chen, Yi Min Xiedoi:10.1016/j.compstruct.2024.117921具有自相似夹杂物的可重入型消蚀蜂窝的力学性能增强A new auxetic honeycomb configuration is proposed by adding self-similar inclusion to the conventional re-entrant hexagonal structure. Theoretical models of the elastic mechanical property are developed for both auxetic honeycombs. The new re-entrant honeycomb exhibits enhanced auxeticity and stiffness compared to the original structure. Both experimental and numerical simulation methods are employed to investigate the in-plane compressive behavior of the auxetic structures, and they show good agreement. The dramatic increase in stiffness observed in the stress-strain curve of the novel auxetic structure can be attributed to self-contact during compression, leading to a significant escalation in plateau stress. The specific energy absorption of the new auxetic structure is approximately 10 times greater than that of the original structure. In addition, the new design enhances the stability of compressive deformation, resulting in a more consistent negative Poisson’s ratio effect. A parametric study of the inclusion’s geometry is also conducted using the validated numerical model, demonstrating that the concave angle of the inclusion is a key parameter to influence the energy absorption capability and compressive stability. Reducing the height-to-length ratio of the entire structure can significantly prevent its buckling. The proposed auxetic honeycomb exhibits significant potential for application in protection engineering, due to its superior stiffness and energy absorption capacity.在传统的可入式六边形结构基础上加入自相似包体,提出了一种新的消声蜂窝结构。建立了两种辅助蜂窝弹性力学性能的理论模型。与原来的结构相比,新的可重新进入的蜂窝结构表现出增强的可塑性和刚度。采用实验和数值模拟两种方法对消声结构的面内压缩特性进行了研究,结果吻合较好。在应力-应变曲线中观察到的这种新型结构的刚度急剧增加可归因于压缩过程中的自接触,导致平台应力显著升高。新结构的比能量吸收比原结构大约10倍。此外,新设计增强了压缩变形的稳定性,导致更一致的负泊松比效应。采用验证的数值模型对夹杂物的几何形状进行了参数化研究,结果表明,夹杂物的凹角是影响其吸能能力和压缩稳定性的关键参数。降低整个结构的高长比可以显著防止结构的屈曲。所提出的消声蜂窝由于其优越的刚度和能量吸收能力,在防护工程中具有重要的应用潜力。Composites Part A: Applied Science and ManufacturingLiquid metal-facilitated flexible electrospun thermoplastic polyurethane fibrous mats with aligned wavelike structure for strain and triboelectric double-mode sensingJiannan Li, Yi Zhao, Xinxin Zhao, Wei Zhai, Kun Dai, Chuntai Liu, Changyu Shendoi:10.1016/j.compositesa.2024.108031液态金属促进柔性电纺热塑性聚氨酯纤维垫与排列波状结构的应变和摩擦电双模传感Flexible electronic skins (E-skins) have attracted widespread attention in artificial intelligence. Nevertheless, it still remains a huge challenge to fabricate multi-functional flexible E-skins through simple and efficient method. Herein, we present an E-skin with aligned wavelike structure for strain and triboelectric double-mode sensing, which is based on the composite of aligned liquid metal (LM)/ thermoplastic polyurethane (TPU) fibrous mat (ALTFM) through a strategy of electrospinning, coating and pre-stretching. The ALTFM possesses good strain sensing performances including wide sensing range (up to 430% strain), fast response/recovery time (400 ms) and long-term durability. The ALTFM based E-skins demonstrates good triboelectric properties, including a high open-circuit voltage (VOC) of 255 V and a large power density of 27.6 mW/m2, resulting in reliable power supply and self-powered sensing capability. The assembled ALTFM can capture the trajectory of full range human motion stimuli, showing a broad application prospect in next generation wearable electronic devices.柔性电子皮肤(e -skin)在人工智能领域引起了广泛关注。然而,如何通过简单高效的方法制备多功能柔性电子皮肤仍然是一个巨大的挑战。在此,我们提出了一种基于定向液态金属(LM)/热塑性聚氨酯(TPU)纤维垫(ALTFM)复合材料,通过静电纺丝、涂覆和预拉伸的策略,具有定向波浪形结构的应变和摩擦电双模传感电子皮肤。ALTFM具有良好的应变传感性能,包括宽传感范围(高达430%的应变),快速响应/恢复时间(400 ms)和长期耐用性。基于ALTFM的电子皮肤具有良好的摩擦电性能,包括255 V的高开路电压(VOC)和27.6 mW/m2的大功率密度,从而实现可靠的供电和自供电传感能力。组装后的ALTFM可以捕捉人体全范围运动刺 激的轨迹,在下一代可穿戴电子设备中显示出广阔的应用前景。Sand Casting-inspired Surface Modification of 3D-printed Porous Polyetheretherketone Scaffolds for Enhancing OsteogenesisJingjie Yu, Yuhan Zhang, Jiabao Guo, Xinrui Shu, Qinqin Lu, Qiang Chendoi:10.1016/j.compositesa.2024.108033基于砂型铸造的3d打印多孔聚醚醚酮支架表面改性促进成骨3D-printed polyetheretherketone (PEEK) scaffolds are developed as novel bone substitutes, however, their bioinert surface hinders osteogenesis and modifying PEEK scaffolds without blocking their inter-connected porous structure is challenged. In this study, 45S5 bioactive glasses (BG) were homogeneously coated on PEEK scaffolds inspired by traditional sand-casting. The structure of PEEK scaffolds was preserved under shaping effect of BG fillers. Modulus, coating yield and hydrophilicity of scaffolds after different thermal treatment time were comparatively investigated. Excellent hydroxyapatite-forming ability of BG-coated scaffolds was confirmed by mineralization study. In-vitro assessments, BG-coated scaffolds cultured with MC3T3-E1 cells present potential as bone implants with excellent cytocompatibility and osteogenic properties. Following similar coating strategy, conductive particles, multi-component particles and template particles were also coated on PEEK surface. The proposed methodology highlights a useful approach towards producing tunable biomedical coatings and microstructure on porous PEEK scaffolds for bone tissue engineering.3d打印聚醚醚酮(PEEK)支架是一种新型的骨替代品,然而其生物惰性表面阻碍了成骨,并且在不阻断其相互连接的多孔结构的情况下修改PEEK支架是一个挑战。在这项研究中,45S5生物活性玻璃(BG)被均匀涂覆在PEEK支架上。在BG填料的塑形作用下,PEEK支架的结构得以保留。比较研究了不同热处理时间后支架的模量、包覆率和亲水性。矿化研究证实了bg包被支架具有良好的羟基磷灰石形成能力。体外评估表明,用MC3T3-E1细胞培养的bg包被支架具有良好的细胞相容性和成骨性能,具有作为骨植入物的潜力。采用类似的涂覆策略,在PEEK表面还涂覆了导电颗粒、多组分颗粒和模板颗粒。提出的方法强调了在骨组织工程的多孔PEEK支架上生产可调生物医学涂层和微观结构的有用方法。Composites Part B: EngineeringMechanical properties and scratch recovery of nanoclay/polyester composite coatings for pre-coated metal (PCM) sheetsWeikang Lin, Yitian Zhao, Grant Edward, Qiang Guo, Tianzhen Chen, Shuning Song, Michael Heitzmann, Darren Martin, Lisbeth Grøndahl, Mingyuan Lu, Han Huangdoi:10.1016/j.compositesb.2024.111217预涂金属(PCM)板材用纳米粘土/聚酯复合涂层的力学性能和划伤恢复Scratch resistance is crucial for the polyester coating on pre-coated metal (PCM) used in domestic appliances and automotive parts to prevent aesthetic degradation and corrosion of the steel substrate. Incorporating nanoclay filler into a polyester coating has demonstrated the potential to enhance scratch resistance. In this study, Lucentite™ (LU) nanoclay with hydrophilic surface modification was added into polyester to fabricate LU/polyester nanocomposite coatings. Nanoindentation and scratch were applied to evaluate the hardness and scratch resistance of the polyester-based coatings, respectively. The result showed that as the LU loading increased from 0.0 to 5.0 wt%, the coating hardness decreased from 187 ± 3 MPa to 107 ± 11 MPa. This softening effect is ascribed to the interactions between the modified clay surface and crosslinker, resulting in reduced degree of crosslinking. Despite the decrease in hardness, adding LU resulted in impressive self-healing abilities of the coatings, attributed to both the reduced crosslinking density and the rotation of the LU platelets. The magnitude of recovery increased with the LU loading. When subjected to scratch loads between 5 and 40 mN, coatings with 5.0 wt% LU demonstrated full recovery after 100 min, while the pure polyester only exhibited 80%–63 % recovery 1000 min after scratch. This unique ability can provide a significant advantage for utilizing these polyester-based composite coatings on PCM sheet.家用电器和汽车部件中使用的预涂金属(PCM)上的聚酯涂层的耐刮擦性至关重要,以防止钢材基体的美观退化和腐蚀。在聚酯涂层中加入纳米粘土填料已被证明具有增强抗刮擦性的潜力。在本研究中,将表面亲水性改性的Lucentite™(LU)纳米粘土加入到聚酯中制备LU/聚酯纳米复合涂层。采用纳米压痕法和划痕法分别评价了聚酯基涂层的硬度和抗划痕性。结果表明,随着LU用量从0.0 wt%增加到5.0 wt%,涂层硬度从187 ± 3 MPa降低到107 ± 11 MPa。这种软化作用归因于改性粘土表面与交联剂之间的相互作用,导致交联度降低。尽管硬度降低,但由于交联密度降低和LU血小板的旋转,添加LU的涂层具有令人印象深刻的自愈能力。随着LU载荷的增加,恢复幅度增大。当受到5到40 mN之间的划痕载荷时,5.0 wt% LU的涂层在100 min后表现出完全的恢复,而纯聚酯涂层在划痕后1000 min仅表现出80%-63 %的恢复。这种独特的能力为在PCM板材上使用这些聚酯基复合涂层提供了显著的优势。Adhesively bonded joints – A review on design, manufacturing, experiments, modeling and challengesYang Wei, Xihong Jin, Quantian Luo, Qing Li, Guangyong Sundoi:10.1016/j.compositesb.2024.111225 粘接接头的设计、制造、实验、建模和挑战综述This paper provides a state-of-the-art review on adhesively bonded joints (ABJs) for composite materials and structures, with a focus on the open literatures from 2016 to 2023 to reflect the latest advances in the field. In this review, joint configurations, adhesive materials, manufacturing techniques, toughening methods and defect detection of ABJs are assessed. Quasi-static and dynamic experimental investigations, analytical and numerical studies on ABJs are discussed in detail. The effects of design parameters on the mechanical behavior of ABJs are evaluated. Design optimization procedures and some typical applications of ABJs are outlined. The review is anticipated to provide the interested readers with an updated comprehension on the latest advances in ABJs and gain new insights into the design and manufacturing of novel ABJ structures, thereby highlighting the prospects of future studies.本文综述了复合材料和结构的粘接接头(ABJs)的研究进展,重点分析了2016年至2023年的公开文献,以反映该领域的最新进展。本文从接头结构、粘结材料、制造工艺、增韧方法和缺陷检测等方面进行了综述。详细讨论了abj的准静态和动态实验研究、分析和数值研究。评估了设计参数对abj力学性能的影响。概述了abj的设计优化过程和一些典型应用。本综述旨在为有兴趣的读者提供对ABJ最新进展的最新理解,并对新型ABJ结构的设计和制造获得新的见解,从而突出未来研究的前景。Exploring the self-nucleation effect: Transforming crystalline morphology for improved mechanical performance of carbon fiber reinforced polyphenylene sulfide compositesYi Ren, Muhuo Yu, Zhouyang Li, Chengchang Ji, Jing Li, Chao Zhang, Jintao Shen, Jianfeng Zhou, Shu Zhudoi:10.1016/j.compositesb.2024.111231 探索自核效应:改变结晶形态提高碳纤维增强聚苯硫醚复合材料力学性能Advanced thermoplastic composites have garnered significant attention due to the advantages such as secondary thermoforming. In the case of thermoplastic composites based on semicrystalline polymers, the self-nucleation (SN) effect induced by repeated thermal cycling can greatly influence the crystallization behavior and mechanical properties of both the matrix and the composites. This study investigated the SN effect of carbon fiber reinforced polyphenylene sulfide (CF/PPS) composites and its impact on non-isothermal crystallization behavior by differential scanning calorimetry, polar optical microscopes and atomic force microscopes. The results revealed that a lower secondary melting temperature led to a higher crystallization temperature. Furthermore, the SN effect significantly improved the fiber/matrix interfacial interaction and mechanical properties of CF/PPS composites. This improvement was evident in the enhanced compression properties, interlaminar shear properties, and in-plane shear properties at different test temperatures. The study also proposed mechanisms for the improved fiber/matrix interfacial interaction and matrix mechanical properties through the SN effect. This work not only enhances our understanding of the changes in mechanical properties of CF/PPS composites due to matrix crystalline morphology changes during secondary thermoforming but also provides insights into improving the manufacturing efficiency and mechanical properties by selecting a low melting temperature to achieve a high crystallization temperature in secondary thermoforming.先进的热塑性复合材料由于具有二次热成型等优点而受到广泛关注。在基于半晶聚合物的热塑性复合材料中,反复热循环引起的自成核效应会极大地影响基体和复合材料的结晶行为和力学性能。采用差示扫描量热法、极性光学显微镜和原子力显微镜研究了碳纤维增强聚苯硫醚(CF/PPS)复合材料的SN效应及其对非等温结晶行为的影响。结果表明,二次熔融温度越低,结晶温度越高。此外,SN效应显著改善了CF/PPS复合材料的纤维/基体相互作用和力学性能。在不同的测试温度下,这种改善在压缩性能、层间剪切性能和面内剪切性能上都有明显的提高。研究还提出了通过SN效应改善纤维/基体界面相互作用和基体力学性能的机理。本研究不仅加深了我们对二次热成型过程中基体结晶形态变化导致的CF/PPS复合材料力学性能变化的理解,而且为在二次热成型过程中选择较低的熔融温度来实现较高的结晶温度来提高制造效率和力学性能提供了见解。A straightforward and efficient gradient pressure method for bamboo flattening: Strain and multi-scale deformationXianke Wang, Xiaohan Chen, Lili Shang, Lin Chen, Bin Huang, Xinxin Ma, Benhua Fei, Huanrong Liu, Changhua Fangdoi:10.1016/j.compositesb.2024.111232一种简单有效的梯度压扁法:应变与多尺度变形Flattening is an environmentally friendly and efficient processing technique that transforms arc-shaped bamboo strips into regular rectangular ones, greatly expanding bamboo's application potential. However, the current method of bamboo flattening requires softening the strips in a high-temperature and high-pressure environment, followed by continuous roller flattening. This process consumes significant energy and does not allow real-time monitoring of the bamboo strips during the process. This study devised a straightforward and efficient gradient pressure method to flatten naturally arc-shaped bamboo strips into rectangular ones within 30 min, all while preserving the complete culm wall structure without any cracks. The analysis of the deformation characteristics during the process revealed that the outer side of the bamboo strip was subjected to compressive stress, while the inner side was subjected to tensile stress. The parenchyma and vessel cells underwent wrinkling and shrinking due to moisture loss and external pressure. Flattening generated horizontal, vertical, and shear strains in bamboo strips, with horizontal strain being predominant, reaching a maximum negative horizontal strain of approximately −0.131. Besides, significant differences were detected in strain among different parts of the bamboo strip. The overall strain exhibited an obvious left-right symmetrical distribution. For the first time this work analyzed the strain distribution and deformation characteristics during the flattening process of arc-shaped bamboo strips while preserving the intact bamboo culm wall structure. The findings of this research provide a novel option of bamboo culm flattening, enhancing the utilization of raw materials and expanding the application of bamboo as engineering materials.扁平化是一种环保高效的加工技术,将弧形竹条转化为规则的矩形竹条,极大地拓展了竹子的应用潜力。然而,目前的竹材压扁方法需要在高温高压环境下软化竹材,然后进行连续辊压扁。这个过程消耗大量的能量,并且在这个过程中不能对竹条进行实时监控。本研究设计了一种简单有效的梯度压力法,在30 min内将自然弧形竹条压平为矩形竹条,同时保留完整的竹墙结构,无任何裂缝。分析过程中的变形特征表明,竹条外侧承受压应力,内侧承受拉应力。薄壁组织和血管细胞由于水分流失和外界压力而发生起皱和收缩。扁平化在竹篾中产生水平应变、垂直应变和剪切应变,以水平应变为主,最大负水平应变约为- 0.131。此外,竹条不同部位的菌种差异显著。整体应变呈现明显的左右对称分布。本文首次分析了弧形竹条在保留完整竹竿墙体结构的情况下扁平化过程中的应变分布和变形特征。本研究结果为竹材扁平化提供了一种新的选择,提高了原材料的利用率,扩大了竹材作为工程材料的应用。Structurally engineered 3D porous graphene based phase change composite with highly efficient multi-energy conversion and versatile applicationsXinbei Zhu, Jingkai Liu, Kerong Yang, Liyue Zhang, Shuaipeng Wang, Xiaoqing Liudoi:10.1016/j.compositesb.2024.111233 结构工程化三维多孔石墨烯基相变复合材料,具有高效多能转换和多功能应用Micro-nano encapsulation strategy combining three-dimensional (3D) porous carriers and phase change materials (PCMs) has been widely investigated due to its structure stability, high efficiency, and designability. However, the current 3D scaffolds suffering from structure regularity are hard to meet the urgent requirements of high energy conversion efficiency and versatile applications. Herein, a 3D porous graphene scaffold (2LrGO@LIG), which is fabricated from polybenzoxazine/graphene oxide (GO) composite using laser irradiation that structurally engineers a gully-shaped surface and a 3D overlapped graphene networks, was employed for PCMs encapsulation. The addition of GO is proved to enhance the quality of produced laser induced graphene (LIG), which could also be reduced into laser-reduced graphene oxide (LrGO) and connect the adjacent LIGs as thermal bridges. As a consequence, the obtained phase change composite (2LrGO@LIG/MA) showed photo-thermal and electro-thermal conversion efficiency of 94.1 % and 99.1 %, respectively. In addition, benefiting from the surface hydrophobicity (135°), high energy storage density (167.7 J/g) and electrical conductivity (307.9 S/m), 2LrGO@LIG/MA also demonstrated great potential in smart building materials and wearable electronic devices. This study provides a facile method for designing advanced PCM composites with multi-energy conversion capacity and application versatility.三维多孔载体与相变材料相结合的微纳封装策略以其结构稳定、效率高、可设计性好等优点得到了广泛的研究。然而,目前的三维支架存在结构不规范的问题,难以满足高能量转换效率和多用途应用的迫切要求。本文采用聚苯并恶嗪/氧化石墨烯(GO)复合材料,通过激光照射制成三维多孔石墨烯支架(2LrGO@LIG),在结构上形成沟壑状表面和三维重叠的石墨烯网络,用于pcm封装。实验证明,氧化石墨烯的加入可以提高激光诱导石墨烯(LIG)的质量,它也可以被还原成激光还原氧化石墨烯(LrGO),并作为热桥连接相邻的LIG。得到的相变复合材料(2LrGO@LIG/MA)光热转换效率为94.1%,电热转换效率为99.1%。此外,得益于表面疏水性(135°)、高能量存储密度(167.7 J/g)和导电性(307.9 S/m), 2LrGO@LIG/MA在智能建筑材料和可穿戴电子设备中也显示出巨大的潜力。该研究为设计具有多能转换能力和应用通用性的先进PCM复合材料提供了一种简便的方法。Composites Science and TechnologyA human muscle-inspired, high strength, good elastic recoverability, room-temperature self-healing, and recyclable polyurethane elastomer based on dynamic bondsShanshan Wang, Xingyu Chen, Lizhen Guo, Sasa Wang, Fuhao Dong, He Liu, Xu Xudoi:10.1016/j.compscitech.2024.110457 一种以人体肌肉为灵感,高强度,良好的弹性可恢复性,室温自愈性,基于动态键的可回收聚氨酯弹性体Polyurethane elastomers have been widely used in aerospace engineering, intelligent electronics, smart buildings, and other high-tech fields. However, preparing polyurethane elastomers with self-healing at room temperature, high toughness, and strength, remains a significant challenge. Hence, inspired by human muscles, A room-temperature self-healing and recyclable polyurethane elastomer was developed. This elastomer possesses tough, high strength, and good elastic recoverability by adjusting the structure of its hard domains. In detail, the obtained polyurethane elastomers exhibit a high tensile strength of 30.3 MPa, an elongation at break of 1114.6 %, toughness of 126.4 MJ/m3, fracture energy of 96.4 kJ/m2, and remarkable anti-fatigue properties as demonstrated by cyclic tensile. Meanwhile, the introduction of asymmetric aliphatic ring structure into the hard domain structure is beneficial for accelerating the exchange rate of dynamic bonds in polyurethane elastomers, resulting in a healing efficiency is up to 90.8 %. In addition, the mechanical properties of the resultant polyurethane elastomers are not lost after being recycled three times. Finally, the polyurethane elastomer is used as the substrate for electromagnetic shielding material, and the electromagnetic shielding efficiency was investigated. This study demonstrates the design of self-healing elastomers at room temperature with high toughness and strength, which provides a new avenue for the development of sustainable electronic materials in the future.聚氨酯弹性体已广泛应用于航空航天工程、智能电子、智能建筑等高科技领域。然而,制备具有室温自愈、高韧性和高强度的聚氨酯弹性体仍然是一个重大挑战。因此,受人体肌肉的启发,开发了一种室温自愈和可回收的聚氨酯弹性体。该弹性体通过调整其硬畴结构,具有高韧性、高强度和良好的弹性可恢复性。制备的聚氨酯弹性体抗拉强度为30.3 MPa,断裂伸长率为1114.6 %,韧性为126.4 MJ/m3,断裂能为96.4 kJ/m2,循环拉伸试验表明,该弹性体具有良好的抗疲劳性能。同时,在硬畴结构中引入不对称脂肪族环结构有利于加快聚氨酯弹性体中动态键的交换速率,其修复效率可达90.8 %。此外,所得聚氨酯弹性体的机械性能在回收三次后不会损失。最后,以聚氨酯弹性体为基材作为电磁屏蔽材料,对其电磁屏蔽效率进行了研究。本研究展示了室温下具有高韧性和高强度的自愈弹性体的设计,为未来可持续电子材料的发展提供了一条新的途径。来源:复合材料力学仿真Composites FEM

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