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【新文速递】2026年5月20日复合材料SCI期刊最新文章

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今日更新:Composite Structures 9 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 1 篇

Composite Structures

Modeling and verification of 2D-C/SiC elastoplastic damage behavior based on micro-mechanism under multiaxial stresses

Zhi Wang, Qiang Yang, Yujie Wang, Weihua Xie, Chenghai Xu, Songhe Meng

doi:10.1016/j.compstruct.2026.120483

多轴应力下基于微机制的2D-C/SiC弹塑性损伤行为建模与验证

The complex nonlinear mechanical behavior of advanced ceramic matrix composites under multiaxial stress states challenges for their engineering design and application. This study focuses on 2D-C/SiC composites and proposes a modeling approach based on micro-mechanism for their elastoplastic damage behavior under multiaxial stresses. By establishing the relationship between microscopic damage mechanisms (matrix cracking and interface debonding) and macroscopic nonlinear mechanical responses (stiffness degradation and residual deformation), an elastoplastic damage constitutive model incorporating physical significance is developed. The model introduces stress-state-dependent coupling coefficients to quantitatively describe the interaction between anisotropic damage/plastic evolution under multiaxial stresses. Model parameters are systematically determined based on experimental data, and the applicability of model is validated under on-axis tension, shear, off-axis tension, and tension of the plate with a hole. The results demonstrate that the proposed model based on micro-mechanism can effectively characterize the nonlinear elastoplastic behavior of 2D-C/SiC composites under multiaxial stresses, so that it can provide a key theoretical model for structural design to describe nonlinear response in complex stresses of large-scale structures.

先进陶瓷基复合材料在多轴应力状态下复杂的非线性力学行为给其工程设计和应用带来了挑战。本研究以2D-C/SiC复合材料为研究对象,提出了一种基于微机制的多轴应力弹塑性损伤建模方法。通过建立细观损伤机制(基体开裂和界面剥离)与宏观非线性力学响应(刚度退化和残余变形)之间的关系,建立了具有物理意义的弹塑性损伤本构模型。该模型引入应力状态相关耦合系数,定量描述多轴应力下各向异性损伤/塑性演化之间的相互作用。基于实验数据系统地确定了模型参数,验证了模型在轴向拉力、剪切拉力、离轴拉力和带孔板拉力下的适用性。结果表明,基于微观机制的模型能够有效表征2D-C/SiC复合材料在多轴应力作用下的非线性弹塑性行为,为结构设计提供了描述复杂应力下大尺度结构非线性响应的关键理论模型。


Geometrically nonlinear an alysis of laminated composite shells incorporating drilling rotation and thickness stretch by a hierarchical quadrature element method

Bo Liu, Yingying Lan, Cuiyun Liu

doi:10.1016/j.compstruct.2026.120482

考虑钻孔旋转和厚度拉伸的层合复合材料壳的几何非线性分析

This work presents a versatile formulation of the Hierarchical Quadrature Element Method (HQEM) for the nonlinear an alysis of laminated composite shells. The formulation incorporates thickness stretch and drilling rotation to enable multi–structure modeling with 3D constitutive relationships. The rotation tensor is obtained via polar decomposition of a modified deformation gradient tensor defined at the shell’s mid-surface. And the drilling rotation constraint was enforced via Lagrange multipliers, thereby enabling the implementation of spatial finite rotations in the director field. The independent nodal distribution capacity of HQEM enables significant simplification in computing residual forces and stiffness matrices within this framework. The accuracy and convergency of the present formulations are verified by a set of benchmarks. Numerical comparisons demonstrate that discarding the quadratic strain terms and the partial derivatives of the thickness stretch parameter can streamline computation without compromising accuracy. In summary, the present formulation overcomes the fundamental limitations of classical shell theory in modeling complex geometries and significantly simplifies the complex computations for laminated shells.

本工作提出了一种多层正交单元法(HQEM)的通用公式,用于层合复合材料壳的非线性分析。该配方结合了厚度拉伸和钻井旋转,实现了具有三维本构关系的多结构建模。旋转张量是通过在壳的中表面定义的修正变形梯度张量的极分解得到的。通过拉格朗日乘法器实现钻井旋转约束,从而实现定向井的空间有限旋转。HQEM的独立节点分布能力使得在该框架内计算剩余力和刚度矩阵的计算大大简化。通过一组基准验证了本公式的准确性和收敛性。数值比较表明,在不影响计算精度的前提下,丢弃二次应变项和厚度拉伸参数的偏导数可以简化计算。综上所述,本文的公式克服了经典壳理论在模拟复杂几何形状方面的基本局限性,极大地简化了层合壳的复杂计算。


Concurrent multi-phase and multiscale topology optimization of fiber-reinforced composites

Jia-Qi Rong, Yi Rong, Hua Liu, Xi-Qiao Feng, Yi Min Xie, Zi-Long Zhao

doi:10.1016/j.compstruct.2026.120481

纤维增强复合材料并行多相多尺度拓扑优化

Fiber-reinforced composites (FRCs) are not only used in aerospace, automobile, and civil engineering, but also widely exist in the biological tissues of animals and plants. Due to their heterogeneity, anisotropy, and structural hierarchy, design optimization of structures made of FRCs remains a challenge. In this paper, we propose a concurrent multi-phase topology form-finding approach for FRCs based on an extended multiscale finite element method. The macroscopic structural topology, the microscopic distributions of multi-phase materials, and the fiber orientations are considered as independent design variables, which are concurrently optimized through a gradient-based algorithm. A mathematical interpolation model is used to describe the constitutive relations of materials at different structural levels. The compliance minimization problems are considered as an example. Sensitivity a nalyses of both macroscopic and microscopic design variables are performed. This approach can guarantee the connectivity between neighboring substructures, which is of significance in, e.g., additive manufacturing and biomechanical morphogenesis. Several numerical examples are provided to examine the effectiveness of the proposed approach. The results show that this approach is capable of generating high-performance multi-material, multiscale topological designs of FRCs, which have clear boundaries at different structural levels. This work holds potential applications in the optimization of heterogenic and hierarchical structures.

纤维增强复合材料(FRCs)不仅应用于航空航天、汽车、土木工程等领域,而且广泛存在于动植物生物组织中。由于FRCs的非均质性、各向异性和结构层次性,FRCs结构的设计优化仍然是一个挑战。本文提出了一种基于扩展多尺度有限元法的FRCs同步多相拓扑寻形方法。将宏观结构拓扑、多相材料微观分布和纤维取向作为独立的设计变量,通过基于梯度的算法并行优化。采用数学插值模型来描述材料在不同结构层次上的本构关系。并以柔度最小化问题为例。对宏观和微观设计变量进行了敏感性分析。这种方法可以保证相邻子结构之间的连通性,这在增材制造和生物力学形态发生等领域具有重要意义。给出了几个数值算例来验证所提方法的有效性。结果表明,该方法能够生成高性能的多材料、多尺度FRCs拓扑设计,并且在不同的结构层次上具有清晰的边界。这项工作在异质和分层结构的优化方面具有潜在的应用前景。


Inverse identification of a two-stage eigenstrain model using macroscopic spring-back and warpage

Hongshuai Wang, Hangyuan Luo, Chenyang Xie, Zhiyong Zhao, Enwei Yan, Junbiao Wang, Yujun Li

doi:10.1016/j.compstruct.2026.120480

基于宏观回弹和翘曲的两阶段特征应变模型的反识别

The eigenstrain model is a novel and efficient method for accurately predicting the curing deformation of composite materials, but it currently lacks a straightforward approach for obtaining input parameters. This study addresses this gap by proposing an inverse method to calibrate a two-stage eigenstrain model directly from the macroscopic deformation of standard test specimens. The inverse framework uniquely leverages the distinct deformation characteristics of L-shaped specimens and flat laminates; spring-back, which is sensitive to rubbery state properties, is used to identify the first set of parameters, while warpage, governed primarily by inelastic strains accumulated in the glassy state, is used to determine the remaining parameters. The accuracy and effectiveness of the calibrated model are validated against both an alytical solutions for L-shaped components and extensive experimental data from various flat laminates. The discussion reveals that the effects of measurement uncertainty and free-edge relaxation on the inversion are negligible. Furthermore, the model was applied to predict the curing deformation of variable-thickness L-shaped parts and complex-shaped T-stringers, with prediction accuracy confirming the practical value of the proposed method for engineering applications.

本征应变模型是一种新颖有效的预测复合材料固化变形的方法,但目前缺乏一种直接获取输入参数的方法。本研究通过提出一种反方法来直接从标准试件的宏观变形校准两阶段特征应变模型,从而解决了这一空白。反框架独特地利用了l形试件和平面层压板的独特变形特征;对橡胶状态特性敏感的回弹用于确定第一组参数,而翘曲主要由玻璃状态下积累的非弹性应变决定,用于确定其余参数。校准模型的准确性和有效性通过l形组件的解析解和来自各种平面层压板的大量实验数据进行了验证。讨论表明,测量不确定度和自由边松弛对反演的影响可以忽略不计。将该模型应用于变厚l型件和复杂t型弦件的固化变形预测,预测精度较高,验证了该方法在工程应用中的实用价值。


Tension buckling and post-buckling phenomena of auxetic metamaterial sandwich plates

Hui-Shen Shen, Zhouyu Zheng

doi:10.1016/j.compstruct.2026.120476

无氧超材料夹层板的拉伸屈曲和后屈曲现象

Mechanical metamaterials exhibiting negative Poisson’s ratio (NPR) properties have emerged as a new class of engineering materials, finding applications across multiple engineering fields and attracting increasingly widespread attention. Here, we design an auxetic sandwich plate with multi-directional NPR characteristics, featuring a core layer composed of graphene platelet (GPL)-reinforced porous metal foam and composite laminated facesheets. We report that when the unloaded edges of this auxetic sandwich plate are constrained, buckling can occur under uniaxial tensile loading. Using a two-step perturbation method, we a nalyze and explore the underlying mechanical mechanism: due to the NPR effect, longitudinal tensile loading increases transverse displacement, and when this transverse displacement is constrained, it induces compressive stress. Once this compressive stress reaches critical value, buckling occurs. Numerical simulations are employed to study the tension buckling and post-buckling response of the auxetic sandwich plate under various conditions, with results compared to its performance under uniaxial compression

具有负泊松比(NPR)特性的机械超材料作为一类新的工程材料,在多个工程领域得到了广泛的应用,引起了越来越广泛的关注。在这里,我们设计了一种具有多向NPR特性的消声夹层板,其核心层由石墨烯板(GPL)增强多孔金属泡沫和复合层压面板组成。本文报道了在单轴拉伸载荷作用下,当该夹层板的未加载边受到约束时,会发生屈曲。采用两步摄动方法,分析和探讨了其潜在的力学机制:由于NPR效应,纵向拉伸载荷增加横向位移,当横向位移受到约束时,产生压应力。一旦压应力达到临界值,就会发生屈曲。采用数值模拟的方法,研究了各种条件下含氧夹层板的张屈曲和后屈曲响应,并与单轴压缩条件下夹层板的性能进行了比较


A stabilized correspondence peridynamic framework for nonlinear anisotropic heat transfer on non-uniform particle distributions

Jiajun Dai, Tao Xue, Xiaobing Zhang

doi:10.1016/j.compstruct.2026.120463

非均匀粒子分布下非线性各向异性传热的稳定对应周动力学框架

This paper presents a stabilized correspondence peridynamic framework for modeling nonlinear transient heat transfer in anisotropic media, specifically addressing the zero-energy mode instabilities inherent in non-ordinary state-based formulations. We identify that spurious temperature oscillations, which are an alogous to hourglass instabilities in mechanics, severely compromise solution fidelity when employing non-uniform particle distributions and large horizon sizes. To mitigate this, we introduce a stabilization technique that augments the heat flux with an artificial potential term, effectively eliminating the rank deficiency of the correspondence operator without altering the underlying physics. The efficacy of the proposed method is rigorously validated through δ -convergence studies, anisotropic wave propagation benchmarks, and nonlinear problems involving temperature-dependent conductivity. Numerical results demonstrate that the stabilized formulation successfully suppresses non-physical oscillations in geometrically complex domains with irregular discretization, where conventional models fail. Furthermore, the method exhibits superior computational efficiency in nonlinear regimes by significantly reducing the number of Newton–Raphson iterations required for convergence compared to unstabilized approaches.

本文提出了一个稳定的对应周动力学框架,用于模拟各向异性介质中的非线性瞬态传热,特别解决了非普通基于状态的公式中固有的零能量模式不稳定性。我们发现,当采用非均匀粒子分布和大视界尺寸时,虚假的温度振荡,类似于力学中的沙漏不稳定性,严重损害了解的保真度。为了缓解这一点,我们引入了一种稳定技术,通过人工势项增加热通量,有效地消除了对应算子的秩缺陷,而不改变底层物理。通过δ收敛研究、各向异性波传播基准以及涉及温度相关电导率的非线性问题,严格验证了所提出方法的有效性。数值结果表明,该稳定公式成功地抑制了不规则离散化的几何复杂区域的非物理振荡,而传统模型无法实现这一目标。此外,与非稳定方法相比,该方法通过显著减少收敛所需的Newton-Raphson迭代次数,在非线性条件下显示出优越的计算效率。


Mesoscopic stress field prediction in solid propellants via integrated graph-convolutional neural networks

Yizhou Qiao, Zhibin Shen, Jiada Huang, Hao Ma

doi:10.1016/j.compstruct.2026.120446

基于集成图卷积神经网络的固体推进剂介观应力场预测

To reduce computational cost and improve single-modal accuracy, this study proposes a multi-modal CNN-GNN surrogate model for predicting mesoscopic stress fields in solid propellants. An optimized random sequential adsorption algorithm generates mesostructures with a 65% packing ratio. Finite element von Mises stress fields under uniaxial tension are constructed for four particle size distributions at 0.1 and 0.2 strains. CNN extracts pixel-level geometric features, while GNN encodes spatial correlations of AP particles. An attention-based dual-path fusion module adaptively integrates features. A “pre-training + decoder fine-tuning” transfer learning strategy enables fast adaptation to the 0.2 strain condition. Using U-Net as the baseline, the hybrid model achieves R2 of 0.8919–0.9357 and MAE of 0.0244 ∼ 0.0303 MPa at 0.1 strain, outperforming pure CNN or GNN models. After transfer learning, it achieves R2 > 0.8574 and MAE < 0.0394 MPa at 0.2 strain, with faster convergence and less overfitting. Current limitations include 2D uniaxial loading and validation using only simulation data without explicit mechanical interaction modeling. Future work will extend to 3D scenarios, incorporate experimental data, and optimize the GNN for encoding mechanical mechanisms.

为了降低计算成本和提高单模态精度,本研究提出了一个多模态CNN-GNN替代模型来预测固体推进剂的介观应力场。优化后的随机顺序吸附算法生成了填料率为65%的介观结构。在0.1和0.2应变下,建立了四种粒径分布的单轴拉伸von Mises应力场有限元模型。CNN提取像素级几何特征,而GNN编码AP粒子的空间相关性。基于注意力的双路融合模块自适应融合特征。“预训练+解码器微调”的迁移学习策略能够快速适应0.2应变条件。以U-Net为基准,混合模型在0.1应变下的R2为0.8919-0.9357,MAE为0.0244 ~ 0.0303 MPa,优于纯CNN或GNN模型。迁移学习后,在0.2应变下达到R2 > 0.8574, MAE < 0.0394 MPa,收敛速度快,过拟合少。目前的限制包括二维单轴加载和验证,仅使用模拟数据,没有明确的机械相互作用建模。未来的工作将扩展到3D场景,纳入实验数据,并优化GNN编码机械机制。


Inverse design method of phononic crystals with customized band gap for different needs: Lightweight and ultimate performance

Lin Liao, Song Yao, Xing Chen, Yingli Li

doi:10.1016/j.compstruct.2026.120478

针对不同需求定制带隙的声子晶体逆设计方法:轻量化和极致性能

Most traditional phononic crystal (PnC) optimization designs only focus on maximizing the band gap (BG) between adjacent orders. For practical engineering scenarios, however, customized BG design is more desirable. To address this issue, this work proposes a novel improved Heaviside function for BG constraints. The proposed function is smooth and differentiable, making it well-suited for gradient-based optimization. On this basis, a two-stage optimization framework is developed for the inverse design of PnCs. Stage 1 minimizes the structural volume under BG constraints to obtain a lightweight initial configuration. Stage 2, based on the results of Stage 1, further maximizes the BG width of the specified order under BG constraints. The two-stage method decomposes the coupled problem into two robust single-objective subproblems solved, avoiding the need for subjective weighting factors in a single-stage multi-objective formulation and the ill-posed problems caused by multi-physical coupling. This method is used to numerically solve the problems of single BG in a single mode and double BGs in different modes, and the customized BG is extended to directional BGs. Finally, the numerical simulation and experiment of transmission loss verifies the effectiveness of this method.

大多数传统的声子晶体优化设计只关注相邻阶间带隙的最大化。然而,对于实际工程场景,定制BG设计更可取。为了解决这个问题,这项工作提出了一个新的改进的Heaviside函数用于BG约束。所提出的函数是光滑和可微的,使其非常适合基于梯度的优化。在此基础上,提出了pnc反设计的两阶段优化框架。第一阶段在BG约束下最小化结构体积,以获得轻量化的初始配置。阶段2在阶段1结果的基础上,在BG约束下进一步最大化指定阶的BG宽度。两阶段方法将耦合问题分解为两个已解的鲁棒单目标子问题,避免了单阶段多目标公式中需要主观加权因子和多物理耦合引起的不适定问题。利用该方法对单模态下的单BG和不同模态下的双BG进行了数值求解,并将自定义BG扩展到定向BG。最后,通过传输损耗的数值模拟和实验验证了该方法的有效性。


Compared behaviour of notched thermoplastic and thermoset carbon reinforced panels under multiaxial loadings

Joël Serra, Florent Grotto, Bruno Castanié, Christophe Bouvet

doi:10.1016/j.compstruct.2026.120475

缺口热塑性和热固性碳增强板在多轴载荷下的性能比较

This study investigates the differences between the behaviour of notched thermoplastic (TP) and thermoset (TS) carbon fibre reinforced polymers under various structural loadings. Large structural samples of TP and TS were subjected to tension, shear, and combined tension + shear loadings using the VERTEX multiaxial test bench to propagate an initial sharp notch. Unlike open-hole specimens, the damaged area extends a lot when a sharp notch is investigated therefore large specimen are important to capture large progressive damage developments before total failure. The tests were monitored with stereo digital image correlation for loading quantification, an infrared camera to track crack propagation, and post-mortem C-scans and tomographies to identify failure modes. Results showed stable crack propagation in all test configurations with significant post-buckling. TS samples exhibited greater fracture process zone compared to TP samples. Tomographies revealed different failure mechanisms at the ply scale for TS and TP, especially under shear loading, with TP displaying much less fibre failures. The progressiveness of crack propagation also differed, with TP showing smaller steps and a more gradual propagation. These findings have significant implications for the design and application of composite structures, highlighting the importance of considering material behaviour at a structural scale, despite very similar strength over the tension-shear domain.

本研究探讨了缺口热塑性(TP)和热固性(TS)碳纤维增强聚合物在不同结构载荷下的行为差异。使用VERTEX多轴试验台,对TP和TS的大型结构样品进行拉伸、剪切和拉伸+剪切组合加载,以传播初始锐缺口。与裸眼试样不同,当研究一个尖锐的缺口时,损伤区域会扩大很多,因此在完全破坏之前,大的试样对于捕捉大的渐进损伤发展是重要的。测试过程中采用了立体数字图像相关技术来量化载荷,红外摄像机来跟踪裂纹扩展,并使用c扫描和层析成像来识别失效模式。结果表明,在所有测试配置中,裂纹扩展稳定,后屈曲明显。与TP样品相比,TS样品表现出更大的断裂过程区。层析成像显示了TS和TP在层数尺度上的不同破坏机制,特别是在剪切载荷下,TP显示的纤维破坏要少得多。裂纹扩展的递进性也不同,TP的扩展步长更小,扩展更缓慢。这些发现对复合材料结构的设计和应用具有重要意义,强调了在结构尺度上考虑材料行为的重要性,尽管在拉伸-剪切领域的强度非常相似。


Composites Part B: Engineering

Polymer Electrolytes in Lithium-Sulfur Batteries: Design Strategies, Interfacial Dynamics, and Performance Optimization

Vennila Selvaraj, Baeksang Yoon, Suresh Sagadevan, Dan Na, Byoenghun Oh, Sangwon Noh, Inseok Seo

doi:10.1016/j.composites b.2026.113833

锂硫电池中的聚合物电解质:设计策略、界面动力学和性能优化

This review highlights the critical role of polymer electrolytes by addressing key challenges in lithium-sulfur (Li-S) batteries, including polysulfide dissolution and shuttle effects, interfacial instability between electrodes, and lithium dendrite formation. The recent advances in solid, gel, and composite polymer electrolytes have significantly improved ionic conductivity, mechanical robustness, and interfacial compatibility, leading to an enhanced cycling stability and rate capability. The functional group engineering for chemical polysulfide confinement, incorporation of nanofillers for physical trapping, and block copolymer design for structural integrity can effectively mitigate active material loss and stabilize the electrode-electrolyte interfaces. In addition, all-solid-state Li-S systems employing robust and self-healing polymer architectures offer improved safety, flexibility, and electrochemical performance. The emerging approaches, including bio-derived polymer systems, in situ polymerization techniques for scalable fabrication, and the integration of advanced characterization with computational modeling. Collectively, these innovations position polymer electrolytes as key enablers for achieving Li-S batteries with high energy densities (>500 Wh kg-1), extended cycle life (>1000 cycles), and strong commercial viability.

这篇综述强调了聚合物电解质的关键作用,解决了锂硫(Li-S)电池的关键挑战,包括多硫化物溶解和穿梭效应,电极之间的界面不稳定性以及锂枝晶的形成。固体、凝胶和复合聚合物电解质的最新进展显著改善了离子电导率、机械稳健性和界面相容性,从而增强了循环稳定性和速率能力。化学聚硫约束的官能团工程、物理捕获的纳米填料的加入以及结构完整性的嵌段共聚物设计可以有效地减少活性物质的损失并稳定电极-电解质界面。此外,全固态Li-S系统采用强大的自修复聚合物结构,提高了安全性、灵活性和电化学性能。新兴的方法,包括生物衍生聚合物系统,可扩展制造的原位聚合技术,以及先进表征与计算建模的集成。总的来说,这些创新将聚合物电解质定位为实现高能量密度(500wh kg-1)、延长循环寿命(500wh kg-1)和强大商业可行性的Li-S电池的关键推手。


Sustainable and non-flammable hybrid composites based on ocean-recycled polyamide 6 reinforced with surface-modified basalt fiber and lignin-derived biocarbon

Suman Kumar Ghosh, Kehinde Olonisakin, Amar K. Mohanty, Manjusri Misra

doi:10.1016/j.composites b.2026.113823

以海洋回收聚酰胺6为基础,表面改性玄武岩纤维和木质素衍生生物碳增强的可持续和不易燃混合复合材料

The growing demand for lightweight, sustainable and fire-resistant materials in electric vehicles (EVs) and the automotive sectors necessitates the development of advanced polymer composites with balanced mechanical, thermal and flammability performance. In this work, non-flammable and high-performance polyamide 6 (PA 6) hybrid composites containing silane-treated basalt fiber, lignin-pyrolyzed biocarbon, ocean-recycled PA 6, and 15 wt% non-halogenated flame retardant (melamine cyanurate) were developed via melt extrusion and injection molding. The silane-treated basalt fiber provided excellent stiffness, while lignin biocarbon produced at 950 °C imparted effective condensed-phase char formation. The synergistic hybrid reinforcement strategy significantly enhanced stiffness, heat stability and flame retardancy while maintaining good processability. The optimized hybrid composites with 10 wt% biocarbon and 20 wt% recycled PA 6 exhibited a 179% increase in tensile modulus and 194% increase in flexural modulus compared to neat PA 6. A heat deflection temperature above 200 °C and 53% reduction in the coefficient of linear thermal expansion were also observed for these composites. These sustainable composites achieved a UL-94 V-0 rating and zero horizontal burning rate while retaining melt flow index values above 10 g/10 min. Dynamic mechanical and rheological an alyses revealed strong filler–matrix adhesion and a stable viscoelastic network, characterized by the lowest C-factor (0.438) and the highest entanglement density (∼14 × 104 mol m-3). Moreover, the non-flammable hybrid composites with 50% sustainability and much lighter (>50%) than metallic counterparts showed strong potential for lightweight EV battery enclosures and structural automotive components.

电动汽车和汽车行业对轻质、可持续和耐火材料的需求不断增长,这就要求开发具有平衡机械、热和可燃性性能的先进聚合物复合材料。在这项工作中,通过熔融挤出和注塑成型,开发了不易燃和高性能的聚酰胺6 (pa6)杂化复合材料,该复合材料含有硅烷处理的玄武岩纤维、木质素热解生物碳、海洋回收的pa6和15%无卤化阻燃剂(三聚氰胺氰脲酸酯)。硅烷处理的玄武岩纤维提供了优异的刚度,而在950°C下产生的木质素生物碳则提供了有效的冷凝相炭形成。协同混合增强策略在保持良好加工性能的同时,显著提高了材料的刚度、热稳定性和阻燃性。与纯pa6相比,含有10 wt%生物碳和20 wt%再生pa6的优化复合材料的拉伸模量增加了179%,弯曲模量增加了194%。该复合材料的热挠曲温度高于200°C,线性热膨胀系数降低53%。这些可持续复合材料达到了UL-94 V-0等级和零水平燃烧速率,同时保持熔体流动指数高于10克/10分钟。动态力学和流变学分析表明,填料-基质粘附性强,具有稳定的粘弹性网络,具有最低的c因子(0.438)和最高的缠结密度(~ 14 × 104 mol m-3)。此外,与金属复合材料相比,具有50%可持续性和更轻(bbb50 %)的不易燃混合复合材料在轻型电动汽车电池外壳和结构汽车部件方面具有强大的潜力。


Graphene Oxide and Chemical Crosslinker Enhanced Water-based Polyurethane Elastomer Nanocomposites

Christian N. Nwosu, Maria Iliut, Constantinos Soutis, Aravind Vijayaraghavan

doi:10.1016/j.composites b.2026.113803

氧化石墨烯和化学交联剂增强水性聚氨酯弹性体纳米复合材料

Graphene oxide (GO) and a water-based crosslinker (WCL) are hydrophilic, hence, were systematically employed to reinforce water-based elastomers (WBEs) using water-based polyurethane (WPU). Structural investigations, including Raman spectroscopy, indicated strong interfacial interactions between WPU and GO or GO-WCL, evidencing synergistic bonding. Mechanical characterization by uniaxial tensile testing and dynamic mechanical a nalysis (DMA) showed substantial property enhancements, with an increase of ∼183 - 308 MPa in tensile modulus (at 3% strain) and a 35 - 39 MPa improvement in tear strength for GO-WBE nanocomposites at 1 wt% loading. The dynamic storage modulus increased to 368.37 ± 19.71 MPa (GO/WPU) and 503.23 ± 15.91 MPa (GO/WPU/WCL) at 1 wt% loading, compared with 117.41 ± 16.42 MPa for neat WPU. Notably, WCL incorporation reduced ultimate tensile strength (UTS), ultimate elongation, and tan δ (damping factor), whereas GO-only nanocomposites exhibited improved performance, including increased UTS across all loadings. Thermal a nalysis further showed that WCL-based nanocomposites had a higher glass transition temperature than the GO-only systems. Thermal decomposition temperatures also increased with GO loading, with GO-only nanocomposites outperforming WCL-based counterparts in several cases. This work provides insight into the crosslinking effects of GO and the synergistic GO-WCL integration within the WPU matrix. Both GO and WCL increased the crosslink density (Cd), which strongly correlated with enhancements in the mechanical and thermal properties of the nanocomposites. Comparatively, GO-only nanocomposites exhibited superior mechanical and thermal performance relative to WCL-infused systems, despite their lower Cd. In general, these GO-WBE nanocomposites demonstrate substantial recycling and sustainability potential for high-performance technical applications. Overall, the robust reinforcement of the WPU matrix through GO and WCL integration positions GO-WBE nanocomposites as strategic materials for sustainable deployment across robotics, coatings, automotive, aerospace, maritime, textiles, sensors, electric vehicles (EVs), and artificial intelligence (AI) manufacturing.

氧化石墨烯(GO)和水基交联剂(WCL)是亲水性的,因此,系统地使用水性聚氨酯(WPU)来增强水基弹性体(WBEs)。包括拉曼光谱在内的结构研究表明,WPU与GO或GO- wcl之间存在强烈的界面相互作用,证明了协同键合。通过单轴拉伸测试和动态力学分析(DMA)进行的力学表征表明,氧化石墨烯- wbe纳米复合材料的性能得到了显著增强,在1 wt%载荷下,拉伸模量增加了~ 183 - 308 MPa(3%应变),撕裂强度提高了35 - 39 MPa。负载为1wt %时,动态存储模量分别为368.37±19.71 MPa (GO/WPU)和503.23±15.91 MPa (GO/WPU/WCL),而纯WPU为117.41±16.42 MPa。值得注意的是,WCL的掺入降低了极限抗拉强度(UTS)、极限伸长率和tan δ(阻尼因子),而氧化石墨烯纳米复合材料的性能有所改善,包括在所有负载下的UTS增加。热分析进一步表明,wcl基纳米复合材料的玻璃化转变温度高于纯氧化石墨烯体系。热分解温度也随着氧化石墨烯负载的增加而增加,在某些情况下,纯氧化石墨烯纳米复合材料的性能优于基于wcl的纳米复合材料。这项工作为氧化石墨烯的交联效应和氧化石墨烯- wcl在WPU矩阵中的协同整合提供了深入的见解。氧化石墨烯和WCL都增加了交联密度(Cd),这与纳米复合材料的力学和热性能增强密切相关。相比之下,尽管氧化石墨烯纳米复合材料的Cd较低,但相对于注入wcl的体系,氧化石墨烯纳米复合材料表现出更优越的机械和热性能。总的来说,这些氧化石墨烯- wbe纳米复合材料在高性能技术应用方面具有巨大的可回收性和可持续性潜力。总体而言,GO- wbe纳米复合材料通过GO- WCL和WPU基体的整合,将成为机器人、涂料、汽车、航空航天、海事、纺织品、传感器、电动汽车(ev)和人工智能(AI)制造领域可持续部署的战略材料。


Cation-Engineered Co–Fe Spinel/rGO Composites with Tuned Magnetocrystalline Anisotropy for Wideband Microwave Absorption

Lan Zhang, Wei Qiao, Tao Sun, Yue Qian, Zhanjun Wu

doi:10.1016/j.composites b.2026.113794

具有调谐磁晶各向异性的阳离子工程Co-Fe尖晶石/氧化石墨烯复合材料用于宽带微波吸收

To enhance comprehensive electromagnetic protection and meet aerospace requirements, rational regulation of magnetic responses in carbon–magnetic composites through microstructure design is critical for achieving broadband electromagnetic wave absorption. Herein, a Co–Fe spinel/reduced graphene oxide composite system (CoxFe9−xOy/rGO) is fabricated via a solvothermal–freeze-drying strategy, enabling the anchoring of 0D spinel nanoparticles onto 2D rGO sheets with low density, while the magnetic performance of the composite is further tailored by adjusting the Co/Fe ratio through controlled Co2+ incorporation. Microscopic characterizations reveal that the nanoscale particles are uniformly anchored on the 2D rGO sheets, forming abundant heterogeneous interfaces between the graphene layers and the particles. Tailoring Co2+ content enhances the composite’s EMA performance initially, yet leads to degradation at excessive levels. Benefiting from the cooperative effects of regulated magnetic loss, moderate dielectric attenuation from the rGO network, and improved impedance matching, the optimized Co1Fe8Oy/rGO composite achieves a minimum reflection loss of −43.38 dB at the thickness of 2.50 mm and an effective absorption bandwidth of 6.53 GHz at 2.23 mm. Furthermore, radar cross-section (RCS) simulations reveal a maximum RCS reduction of 37.29 dBm2 under normal incidence, with RCS values remaining below −15 dBm2 over a wide angular range (−60° to 60°). This work manifests the potential of cation regulation for tuning magnetic responses in carbon–ferrite composite systems.

为了提高碳磁复合材料的综合电磁防护能力,满足航空航天要求,通过微结构设计合理调节碳磁复合材料的磁响应是实现宽带电磁波吸收的关键。本文采用溶剂热-冷冻干燥的方法制备了Co - Fe尖晶石/还原氧化石墨烯复合体系(CoxFe9−xOy/rGO),使0D尖晶石纳米颗粒锚定在低密度的2D rGO薄片上,同时通过控制Co2+的掺入来调节Co/Fe比,进一步调整复合材料的磁性能。微观表征表明,纳米级颗粒均匀地锚定在二维氧化石墨烯薄片上,在石墨烯层和颗粒之间形成丰富的非均质界面。调整Co2+含量最初可提高复合材料的EMA性能,但会导致过量的降解。优化后的Co1Fe8Oy/rGO复合材料在2.50 mm厚度处的反射损耗最小为- 43.38 dB,在2.23 mm处的有效吸收带宽为6.53 GHz,得益于磁损耗调节、rGO网络的介电衰减适度和阻抗匹配改善的协同效应。此外,雷达截面(RCS)模拟显示,在正常入射下,RCS值最大减少了37.29 dBm2,在宽角范围内(- 60°至60°)RCS值保持在- 15 dBm2以下。这项工作表明了阳离子调节在碳铁氧体复合体系中调节磁响应的潜力。


Composites Science and Technology

Comparison of fiber volume fraction measurement methods from composite micrographs

Félix Thébault, Alexandre Clément, Sylvain Fréour, Gwénolé Le Moal, Pascal Casari

doi:10.1016/j.compscitech.2026.111689

复合显微照片中纤维体积分数测量方法的比较

Mechanical performance of composite materials is closely linked to their microstructural features, especially the Fiber Volume Fraction (FVF) and its local variations. Often based on optical micrograph an alysis, FVF characterization is essential for reliable material modeling. However, existing FVF measurement methods based on optical micrographs show significant variability and lack standardized evaluation protocols. This study introduces a comparison of FVF characterization methods using a database of artificially generated micrographs with known ground truth values. Five methods are evaluated: three traditional computer vision techniques (Otsu’s thresholding, Watershed, and Fiber Counting) and two machine learning models. Results show that Otsu’s thresholding method provides the best accuracy among computer vision approaches and is the most cost-effective when machine learning is not feasible. Machine learning models outperform traditional methods in terms of accuracy and robustness, but the labeling of the training dataset is often prone to biases. Strengths and limitations of each method are discussed in detail, and their application is illustrated on a real micrograph exhibiting an FVF gradient near a resin-rich area, to link FVF variations with mechanical properties.

复合材料的力学性能与其微观结构特征密切相关,特别是纤维体积分数(FVF)及其局部变化。通常基于光学显微照片分析,FVF表征对于可靠的材料建模至关重要。然而,现有的基于光学显微照片的FVF测量方法存在显著的可变性,并且缺乏标准化的评估方案。本研究介绍了使用人工生成的具有已知地面真值的显微照片数据库的FVF表征方法的比较。本文评估了五种方法:三种传统的计算机视觉技术(Otsu的阈值法、分水岭法和纤维计数法)和两种机器学习模型。结果表明,Otsu的阈值分割方法在计算机视觉方法中提供了最好的精度,并且在机器学习不可行的情况下是最具成本效益的。机器学习模型在准确性和鲁棒性方面优于传统方法,但训练数据集的标记往往容易产生偏差。详细讨论了每种方法的优点和局限性,并在真实的显微照片上展示了富树脂区域附近的FVF梯度,以将FVF变化与机械性能联系起来。



来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveOpticalSystem断裂复合材料非线性燃烧化学拓扑优化光学通用航空航天汽车增材裂纹理论材料
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【新文速递】2026年5月13日固体力学SCI期刊最新文章

今日更新:International Journal of Solids and Structures 1 篇,Mechanics of Materials 2 篇,International Journal of Plasticity 2 篇,Thin-Walled Structures 3 篇International Journal of Solids and StructuresBuilding a monostable tetrahedronGergő Almádi, Robert J. MacG. Dawson, Gábor Domokosdoi:10.1016/j.ijsolstr.2026.114068 构造单稳定四面体In this paper we describe what we believe to be the first working model of a monostable tetrahedron, which, if supported on a horizontal plane, would only rest in a stable position on one of its faces. If positioned on any other face, it would tip over its edges to arrive at the stable face. The sequence in which faces are visited is called the tipping sequence of the monostable tetrahedron. We prove that for any convex body K and any desired center of mass O in the interior of K , the ratio of the maximum and minimum density associated with any density distribution producing O as the center of mass of K will achieve its minimum if K is binary, i.e. it is composed by two homogeneous parts, separated by a plane passing through O . If O is not the center of mass of the homogeneous body then this plane is unique. We define 6 combinatorial classes of binary monostable tetrahedra based on their geometry and on their respective tipping sequences. Combining this theory with results on monostable tetrahedra from an earlier paper and with a numerical search algorithm we identify local minima for the ratio of maximal and minimal density in 5 out of the 6 combinatorial classes and we design a binary tetrahedron belonging to the lowest minimum out of these 5. Here, the ratio of densities of the heavy and light parts is approximately 907, and we believe the structure to be close to the global optimum in a degenerate combinatorial class, belonging simultaneously to two combinatorial classes. We also demonstrate a working physical model of this tetrahedron which we dubbed Bille.在本文中,我们描述了我们认为是单稳定四面体的第一个工作模型,如果支撑在一个水平面上,它只会在它的一个面上处于稳定的位置。如果它被放置在其他面上,它就会越过它的边缘到达稳定的面。面被访问的序列称为单稳定四面体的倾斜序列。我们证明了对于任何凸体K和K内部的任何期望质心O,如果K是二进制的,即它由两个均匀的部分组成,由一个经过O的平面分开,那么与产生O作为K质心的任何密度分布相关的最大和最小密度之比将达到最小值。如果0不是均匀物体的质心,那么这个平面是唯一的。根据二元单稳定四面体的几何形状及其各自的倾转序列,定义了6个组合类。将此理论与前人关于单稳定四面体的研究结果相结合,并结合数值搜索算法,确定了6个组合类中5个类的最大与最小密度之比的局部极小值,并设计了一个属于这5个类中最小值的二元四面体。在这里,重、轻部件的密度比约为907,我们认为该结构在一个退化组合类中接近全局最优,同时属于两个组合类。我们还演示了这个四面体的工作物理模型,我们称之为Bille。Mechanics of MaterialsCompaction of porous materials under dynamic loading: A comparison of the p − α and ɛ − α model for concrete and concrete-like materialsChristoph Grunwald, Luis Brunnabend, Werner Riedel, Johann Maltandoi:10.1016/j.mechmat.2026.105708动荷载作用下多孔材料的压实:混凝土和类混凝土材料的p−α和α模型的比较This work investigates the compaction behavior of concrete and adobe considering its porosity under dynamic loading. Two evolution equations for the porosity, the p − α and the ɛ − α model, are detailed and compared. The p − α model is well established in conjunction with the RHT model for concrete and parameter for different concrete grades are available. Unfortunately, the model describes the porosity as a function of the pressure, rendering the formulation implicit with accompanying high computational costs in explicit time integration schemes. In contrast, the ɛ − α model offers a simplified approach by linking porosity to the volumetric strain, a measure which is known at the beginning of an integration cycle. This model has found wide spread in the geological community where astronomical problems are of interest, but has not yet been applied to construction materials. We compare standard single element compaction paths as well as high dynamic planar plate impact tests for concrete and derive parameter sets for the ɛ − α model, which yield almost identical results as the p − α model. Computational efforts are reduced, however, limitations in the choice of the parameters make the model in rare cases less flexible compared to the p − α description.本文研究了混凝土和土坯在动荷载作用下的压实特性。详细比较了两种孔隙度演化方程p−α模型和ε−α模型。结合混凝土的RHT模型建立了p−α模型,并给出了不同混凝土等级的参数。不幸的是,该模型将孔隙度描述为压力的函数,使得公式隐式化,同时在显式时间积分方案中伴随着高昂的计算成本。相比之下,ε−α模型通过将孔隙度与体积应变联系起来提供了一种简化的方法,体积应变是在积分周期开始时已知的一种度量。这个模型在对天文问题感兴趣的地质学界得到了广泛的应用,但尚未应用于建筑材料。我们比较了混凝土的标准单单元压实路径和高动态平面板冲击试验,并推导了模型的参数集,其结果与p - α模型几乎相同。计算量减少了,然而,参数选择的限制使模型在极少数情况下比p−α描述更不灵活。Role of fiber dispersion in the torsion-induced Poynting effect of biological tissuesJayant Kumar, Deepak Kumardoi:10.1016/j.mechmat.2026.105728纤维分散在生物组织扭转诱导的坡印亭效应中的作用Collagen and/or elastin fibers are key load-bearing constituents of biological tissues. To realistically model the Poynting effect in biological tissues, which refers to the expansion or contraction of a material in directions perpendicular to an applied twist or shear, fiber dispersion cannot be neglected. The purpose of this work is to examine the often-ignored mechanics of fiber dispersion in accurately predicting the torque and axial stress responses of soft tissues under torsion, with particular emphasis on the Poynting effect. To model the critical role of fiber dispersion, a well-established generalized structural tensor framework is employed. Unlike the conventional quadratic term ( I 4 ∗ − 1 ) 2 , which causes unphysical instabilities associated with negative instantaneous stiffness under specific deformation regions of tissues, an amended form of strain energy density with a nonlinear term I 4 ∗ − m − 1 , m &gt; 0 , is formulated. The impact of fiber dispersion on torque and axial stress is illustrated for white rabbit papillary muscle samples by comparing anisotropic modes to isotropic modes, with and without fiber-dispersion effects.胶原蛋白和/或弹性蛋白纤维是生物组织的关键承重成分。为了真实地模拟生物组织中的坡印亭效应,即材料在垂直于施加扭转或剪切的方向上的膨胀或收缩,纤维色散不能被忽视。这项工作的目的是研究经常被忽视的纤维分散力学,以准确预测扭转下软组织的扭矩和轴向应力响应,特别强调坡印亭效应。为了模拟光纤色散的关键作用,采用了一个完善的广义结构张量框架。与传统的二次项(I 4∗−1)2不同,它在组织的特定变形区域下导致与负瞬时刚度相关的非物理不稳定性,一个非线性项I 4∗−m−1,m &gt; 0的应变能密度的修正形式被表述出来。通过比较具有和不具有纤维分散效应的各向异性和各向同性模式,说明了纤维分散对白兔乳 头肌样品的扭矩和轴向应力的影响。International Journal of PlasticityBreaking the strength-ductility trade-off in copper alloy laminates by heterostructure homogenizationHaitao Gao, Kun Qiao, Zhide Li, Lingling Song, Alexander Pesin, Charlie Kong, M.W. Fu, Hailiang Yudoi:10.1016/j.ijplas.2026.104726利用异质组织均质化技术打破铜合金层合板的强度-塑性平衡The development of high-strength metallic materials is typically restricted by the strength-ductility trade-off, and conventional alloying techniques often result in higher production costs. To address these challenges, a “heterostructure-homogenization” strategy is posited. A complete and fully homogenized transition zone was achieved in a 200-layer heterostructure-homogenized laminate (HHL) comprising T2 Cu/QBe2.0 beryllium copper by deliberately setting the single-layer thickness to be s maller than the interdiffusion width. This design enables sufficient interelement diffusion, thereby forming a monocrystalline layer structure embedded with nanoprecipitates. Atomic diffusion facilitated the refinement of γ precipitates in the beryllium copper layer into 110 nm angular γ phases, whereas 12 nm-scale nanoprecipitates were nucleated on the T2-Cu side. Notably, with a 50% reduction in alloying elements, the HHL sample exhibited a tensile strength (651±5 MPa) comparable to that of QBe2.0 beryllium copper (729±9 MPa), whereas the elongation to fracture was increased by 307% (from 4.8±0.3% to 19.7±0.8%) and the electrical conductivity was improved by 110% (from 23.6 %IACS to 49.1 %IACS). Microstructural an alyses demonstrate that the synergistic effect of monocrystalline texture and homogeneous nanoprecipitates suppresses crack nucleation, while the interfacial transition zone promotes uniform dislocation distribution. Therefore, this strategy overcomes the performance limitations of conventional heterogeneous structures, offering a novel paradigm for developing low-cost copper alloys with integrated high strength and ductility.高强度金属材料的发展通常受到强度与延性权衡的限制,而传统的合金化技术往往导致较高的生产成本。为了应对这些挑战,提出了“异质结构-均质化”策略。在由T2 Cu/QBe2.0铍铜组成的200层异质结构均质层压板(HHL)中,通过设置单层厚度小于互扩散宽度,实现了完全均匀化的过渡区。这种设计使元素间充分扩散,从而形成嵌入纳米沉淀物的单晶层结构。原子扩散使铍铜层中的γ析出相细化为110 nm角γ相,而T2-Cu侧则形成12 nm尺度的纳米析出相成核。值得注意的是,当合金元素减少50%时,HHL样品的抗拉强度(651±5 MPa)与QBe2.0铍铜(729±9 MPa)相当,而断裂伸长率提高了307%(从4.8±0.3%提高到19.7±0.8%),电导率提高了110%(从23.6% IACS提高到49.1% IACS)。微观组织分析表明,单晶织构和均匀的纳米沉淀物的协同作用抑制了裂纹的形核,而界面过渡区促进了位错的均匀分布。因此,该策略克服了传统非均质结构的性能限制,为开发低成本、高强度和高延展性的铜合金提供了新的范例。Machine learning based constitutive modelling for thermal-elasto-plasto amorphous polymersKeyi Jiang, Jici Wen, Yongmao Pei, Yujie Weidoi:10.1016/j.ijplas.2026.104725基于机器学习的热弹塑性非晶聚合物本构建模For its superior recyclability, abundance in resources, and easiness in shape-forming, the application of amorphous thermoplastic polymers as structural materials is ever-growing. The intertwining mechanical, thermal, rate-dependence at both elastic and plastic stages, pressure-sensitivity characteristics, in combination with large deformation, have attracted the attention of the plasticity community. Here we design a physics-driven machine learning (PD-ML) constitutive framework to reconstruct the temperature, stress and rate-dependent deformation in amorphous polymers. We have applied the framework to three exemplary amorphous polymers, poly(methyl methacrylate), polycarbonate, and Zeonex. A finite element (FE) procedure based on the PD-ML constitutive framework is developed. The integration of PD-ML with FE procedure inherits the power of FE an alysis and the accuracy originated from PD-ML in describing temperature, stress and rate-dependent mechanical response of amorphous polymer. We demonstrate that the PD-ML model, fed with limited experimental results, can predict the mechanical response of amorphous polymers in a wide span of temperature and deformation rate and for a broad suit of experiments including uni-axial deformation, embossing, indentation and shear localization under plane strain compression. The constitutive framework could be readily generalized to a broad range of materials exhibiting perplexing temporal, spatial and multi-field coupling.无定形热塑性聚合物具有可回收性好、资源丰富、易成型等优点,作为结构材料的应用日益广泛。其力学、热学、弹塑性阶段速率依赖、压敏特性以及大变形等相互交织的特点,引起了塑性界的广泛关注。在这里,我们设计了一个物理驱动的机器学习(PD-ML)本构框架来重建非晶聚合物的温度、应力和速率相关变形。我们已经将该框架应用于三种典型的非晶聚合物,聚(甲基丙烯酸甲酯),聚碳酸酯和Zeonex。开发了一种基于PD-ML本构框架的有限元程序。PD-ML与有限元程序的集成继承了有限元分析的强大功能和PD-ML在描述非晶聚合物的温度、应力和速率相关力学响应方面的准确性。我们证明了PD-ML模型,在有限的实验结果的支持下,可以预测非晶聚合物在大范围的温度和变形速率下的力学响应,以及在平面应变压缩下的单轴变形、压纹、压痕和剪切局部化等广泛的实验。本构框架可以很容易地推广到广泛的材料表现出复杂的时间,空间和多场耦合。Thin-Walled StructuresPost-Fire Simulated Mechanical Properties of Plas ma Arc Welded Dissimilar DP590-DP780 SteelsA. Rajesh Kannan, Hafiz Muhammad Rehan Tariq, Taemin Jeon, N. Siva Shanmugam, Minki Kim, Tea-Sung Jundoi:10.1016/j.tws.2026.115104不同DP590-DP780钢等离子弧焊后的模拟力学性能The post-fire mechanical performance of dissimilar dual-phase (DP) steel welded joints is critical for the structural integrity of automotive components exposed to elevated temperatures. This study systematically investigates the post-fire behavior of plas ma arc-welded (PAW) DP590-DP780 steel joints heated to 300, 600, and 900°C and then air-cooled. Microstructural evolution, hardness distribution, and tensile properties were evaluated to elucidate the temperature-dependent response. The fusion zone (FZ) in the as-welded condition primarily consisted of martensite, whereas post-fire exposure induced significant phase transformations. At 300°C, partial martensite tempering caused moderate softening with limited strength loss. Exposure at 600°C resulted in extensive tempering and the formation of ferrite-tempered martensite, which enhanced ductility while maintaining adequate strength. In contrast, exposure at 900°C resulted in recrystallization and heterogeneous phase re-transformation, producing irregular lath martensite, bainite, tempered martensite, and grain-boundary ferrite. This microstructural heterogeneity increased FZ hardness but caused pronounced softening in adjacent regions, leading to a mechanical mis match and a substantial reduction in ductility. A predictive model for post-fire mechanical properties of dissimilar DP steel weldments, adapted from prior research, was applied using a simplified three-parameter formulation. The results demonstrate that post-fire exposure temperature critically governs the microstructure-property relationship, providing a balance between strength and ductility. These findings provide guidance for evaluating the residual performance and structural reliability of dissimilar DP steel weldments in automotive applications.不同双相钢(DP)焊接接头的火灾后力学性能对高温下汽车零部件的结构完整性至关重要。本研究系统地研究了等离子弧焊(PAW) DP590-DP780钢接头加热到300、600和900℃,然后风冷后的火灾行为。显微组织演变,硬度分布和拉伸性能进行了评估,以阐明温度依赖的响应。在焊接状态下,熔合区(FZ)主要由马氏体组成,而在火灾后,熔合区发生了明显的相变。在300℃时,部分马氏体回火导致适度软化,强度损失有限。在600℃下暴露导致大量回火并形成铁素体回火马氏体,在保持足够强度的同时增强了延展性。而在900℃下暴露则导致再结晶和非均相再转变,形成不规则板条马氏体、贝氏体、回火马氏体和晶界铁素体。这种微观组织的不均匀性增加了FZ硬度,但在邻近区域造成明显的软化,导致机械失配和延展性的大幅降低。采用简化的三参数公式,建立了不同DP钢焊接件火灾后力学性能的预测模型。结果表明,火灾后的暴露温度对微观组织-性能关系起着关键的控制作用,在强度和延性之间提供了平衡。这些发现为评价不同DP钢焊接件在汽车应用中的残余性能和结构可靠性提供了指导。Morphing characteristics of series-connected composite laminates under mechanical and piezoelectric actuation with clamped boundary conditionsP.R. Manu, P.M. Anilkumar, A. Haldar, B.N. Raodoi:10.1016/j.tws.2026.115059夹紧边界条件下机械和压电驱动下串联复合材料层合板的变形特性Unsymmetrical composite laminates exhibit significant potential due to their inherent bistable behavior, which arises from thermally induced residual stresses developed during curing. This unique characteristic offers a distinct advantage in morphing applications, where continuous shape-change capabilities are desired. By connecting multiple bistable composite shells in series, it is possible to achieve a surface with a high degree of multistability. However, imposed boundary constraints critically affect the morphing capability through their influence on the structural stability landscape. Most of the existing modeling and design studies employ idealized center-fixed boundary conditions, which often do not represent realistic application scenarios. For instance, clamped edge boundary conditions can have a detrimental effect on multistability, sometimes even reducing it to monostability. This study aims to design series-connected multistable laminates with one edge clamped, investigating how such constraints affect the multistable behavior. An efficient strategy utilizing a transition region with a different unsymmetrical layup, connecting to the unsymmetrical connected multistable laminates, has been explored to mitigate the adverse effects of clamping and thereby preserve multistability. A dedicated nonlinear FE modeling has been adopted for the an alysis. Once a viable baseline design is established, the laminate configuration is manufactured, and the displacement profiles predicted by the FE model are validated experimentally. The snap-through process is initially investigated under mechanical loading. Subsequently, piezoelectric macro fiber composite actuators are incorporated to actively induce snap-through transitions between the stable equilibrium configurations. Ultimately, the study addresses two key aspects: (1) the effect of clamped boundary conditions on multistability, and (2) the additional influence of piezoelectric actuation on shape transitions. In all these studies, the out-of-plane displacements of the modeled laminates are an alyzed, along with the corresponding snap-through requirements. These results provide new perspectives on the application of multistable composite laminates in morphing structures by expanding the feasible design space under realistic boundary constraints.非对称复合层压板由于其固有的双稳态行为而表现出显著的潜力,这是由固化过程中产生的热诱导残余应力引起的。这种独特的特性在需要连续形状变化功能的变形应用中提供了明显的优势。通过串联多个双稳态复合壳,可以实现具有高度多稳定性的表面。然而,施加的边界约束通过对结构稳定性景观的影响而严重影响变形能力。现有的建模和设计研究大多采用理想化的中心固定边界条件,往往不能代表实际应用场景。例如,箝位边缘边界条件会对多稳定性产生不利影响,有时甚至会使其降为单稳定性。本研究旨在设计单边箝位的串联多稳定层压板,研究这些约束如何影响多稳定性能。研究了一种有效的策略,利用具有不同不对称层合的过渡区域,连接到不对称连接的多稳定层压板,以减轻夹紧的不利影响,从而保持多稳定性。采用了专门的非线性有限元模型进行分析。一旦确定了可行的基线设计,就可以制造层压板结构,并通过实验验证有限元模型预测的位移曲线。在机械载荷下初步研究了断裂过程。随后,采用压电宏观纤维复合促动器来主动诱导稳定平衡构型之间的过断转变。最后,该研究解决了两个关键方面:(1)箝位边界条件对多稳定性的影响,以及(2)压电驱动对形状转变的附加影响。在所有这些研究中,分析了模型层压板的面外位移,以及相应的snap-through要求。这些结果扩大了在现实边界约束下的可行设计空间,为多稳定复合材料层合板在变形结构中的应用提供了新的视角。Fatigue creep characteristics and performance prediction of PTFE gaskets undergone cryogenic liquid oxygen immersion agingZhan Liu, Wenlong Xue, Jin Bai, Jibin Shen, Zhongzhu Zhangdoi:10.1016/j.tws.2026.115106低温液氧浸渍老化PTFE垫片的疲劳蠕变特性及性能预测Due to excellent advantages, Polytetrafluoroethylene PTFE material is widely used in extreme environments, such as extremely low temperature and ultra-high pressure. Until now, there is still a lack of fatigue creep performance investigations of PTFE materials at cryogenic condition, especially at liquid oxygen temperature. In this study, the PTFE sealing gaskets used in an aerospace cryogenic liquid oxygen filling system were adopted as research object. The selected PTFE samples were immersed in liquid oxygen for several aging treatments, and the related mechanical performance of liquid oxygen aged samples were experimentally tested. The static compression mechanical performance and fatigue creep characteristics of cryogenic aged PTFE samples were systematically investigated. The quantitative an alysis was conducted on influences of three factors, namely loading stress level, cryogenic aging cycle number, and load holding duration, on the strain response of PTFE samples. Based on experimental data, a multi factor statistical model was established using partial least squares regression (PLSR) method, and the material life was reasonably predicted through fitting S-N curve. Some key findings were achieved. This research is significant to depth understanding the evolution of fatigue creep behavior of PTFE gaskets undergone cryogenic immersion aging treatments.聚四氟乙烯PTFE材料由于具有优异的优点,被广泛应用于极低温、超高压等极端环境中。迄今为止,对聚四氟乙烯材料在低温条件下,特别是在液氧温度下的疲劳蠕变性能的研究仍然缺乏。本研究以航天低温液氧填充系统中使用的聚四氟乙烯密封垫片为研究对象。将选定的PTFE试样浸泡在液氧中进行多次时效处理,并对其相关力学性能进行了实验测试。系统地研究了低温老化PTFE试样的静态压缩力学性能和疲劳蠕变特性。定量分析了加载应力水平、低温老化循环次数、载荷保持时间三个因素对PTFE试样应变响应的影响。基于实验数据,采用偏最小二乘回归(PLSR)方法建立了多因素统计模型,并通过拟合S-N曲线对材料寿命进行了合理预测。取得了一些重要发现。本研究对深入了解低温浸渍时效处理后聚四氟乙烯垫片疲劳蠕变行为的演变具有重要意义。来源:复合材料力学仿真Composites FEM

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