首页/文章/ 详情

【新文速递】2025年11月6日固体力学SCI期刊最新文章

8小时前浏览8
 

今日更新:Journal of the Mechanics and Physics of Solids 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 3 篇

Journal of the Mechanics and Physics of Solids

A viscoelastic micro-stretch theory for monodomain nematic liquid crystal elastomers

Yuefeng Jiang, Zengting Xu, Rui Xiao, Sanjay Govindjee, Thao D. Nguyen

doi:10.1016/j.jmps.2025.106412

单畴向列液晶弹性体的粘弹性微拉伸理论

Liquid crystal elastomers (LCEs) combine the anisotropic self-ordering behavior of liquid crystals with the dissipative viscoelastic behavior of elastomers. This combination produces unique behaviors, including a large strain response to cooling past the nematic-isotropic transition temperature, rate-dependent soft stress response, and enhanced dissipation compared to traditional elastomers. To capture these phenomena, we develop a finite-deformation viscoelastic micro-stretch theory for monodomain nematic elastomers, which describes the coupled mechanis ms of viscous mesogen ordering, viscous director rotation, and viscoelastic network deformation. We then specialize the generalized theory to model the thermomechanical behavior of uniaxial nematic elastomers, and examine its predictions through material-point and boundary-value computations. The latter employs a finite element framework that includes the Frank-like energy terms. The numerical examples explore the thermal deformation response to temperature cycling across the nematic-isotropic transition at different temperature scan rates and mechanical pre-loads, as well as the isothermal uniaxial tension stress response. We further present new experimental results that investigate the effect of mechanical loading on thermally driven phase transformations. These experiments reveal an unexpected phenomenon wherein samples cooled into the nematic state under a perpendicular pre-load exhibit a dramatic mode switch in their anisotropic thermal deformation response. The proposed model successfully predicts this effect and further provides a plausible microstructural explanation. Altogether, these studies demonstrate the rich and complex phenomena that emerge from the full coupling of the evolving scalar order parameter, rotating director, and mechanical deformation.

液晶弹性体(LCEs)结合了液晶的各向异性自有序行为和弹性体的耗散粘弹性行为。这种组合产生了独特的性能,包括冷却超过向列向各向同性转变温度时的大应变响应,与传统弹性体相比,速率相关的软应力响应以及增强的耗散。为了捕捉这些现象,我们发展了单域向列弹性体的有限变形粘弹性微拉伸理论,该理论描述了粘性介观有序、粘性导向旋转和粘弹性网络变形的耦合机制。然后,我们专门研究了广义理论来模拟单轴向列弹性体的热力学行为,并通过材料点和边值计算来检验其预测。后者采用了包含Frank-like能量项的有限元框架。数值算例探讨了在不同温度扫描速率和机械预载荷下,沿向列-各向同性转变的温度循环对热变形的响应,以及等温单轴拉伸应力响应。我们进一步提出了新的实验结果,研究了机械载荷对热驱动相变的影响。这些实验揭示了一个意想不到的现象,即在垂直预载荷下冷却到向列状态的样品在其各向异性热变形响应中表现出戏剧性的模式切换。提出的模型成功地预测了这种效应,并进一步提供了一个合理的微观结构解释。综上所述,这些研究表明,从演化的标量序参数、旋转方向和机械变形的完全耦合中出现了丰富而复杂的现象。


International Journal of Plasticity

Molecular dynamics study on the multi-spallation of Ti-6Al-4V titanium alloy caused by non-planar effect of shock wave induced by microscopic interface

Qianhua Yang, Yang Yang, Binwen Wang, Yupei Guo, Xiang Chen

doi:10.1016/j.ijplas.2025.104542

微观界面引起的非平面激波效应对Ti-6Al-4V钛合金多重裂裂的分子动力学研究

The shock-induced multi-spall processes of nanocrystalline titanium alloys were simulated based on molecular dynamics method in this study to reveal the multi-spall damage mechanis m caused by non-planar effect of shock wave induced by microscopic interface. The microscopic interface in nanocrystalline titanium alloys caused non-planar effect of shock wave propagation and hindered shock wave propagation. The shapes of non-planar shock wave in nanocrystalline dual-phase titanium alloys were affected by the distribution of second phase grain. Based on the relationship between the evolution law of tensile stress and the nucleation principle of multi-spall voids, it was found that the multi-spall voids nucleated at microscopic interface under tensile stress generated by the encounter between the secondary reflected wave and the reflected wave for the first time. The non-uniform distribution of tensile stress generated by the encounter between the non-uniform propagation reflected waves led to the non-uniform distribution of multi-spall voids at microscopic interface. The increase of dislocation density caused by second phase grain hindered the secondary void nucleation in nanocrystalline dual-phase titanium alloys, resulting in the difference in secondary void nucleation between nanocrystalline single-phase titanium alloy and nanocrystalline dual-phase titanium alloys. The damage rate (D˙) at the spall stage and strain rate (ε˙) at the shock stage were positively correlated and followed the relationship: D˙=aε˙b (a and b  were fitting parameters and related to the microstructure of material and shock conditions). The multi-voids still nucleated at microscopic interfaces and the intergranular spall occurred in nanocrystalline titanium alloys although the shock velocity increased.

本研究基于分子动力学方法模拟了纳米晶钛合金在冲击作用下的多层剥落过程,以揭示由微观界面引起的冲击波非平面效应所导致的多层剥落损伤机制。纳米晶钛合金中的微观界面导致冲击波传播的非平面效应,并阻碍了冲击波的传播。纳米晶双相钛合金中非平面冲击波的形状受第二相晶粒分布的影响。基于拉伸应力演化规律与多层剥落空洞成核原理之间的关系,发现由二次反射波与首次反射波相遇产生的拉伸应力在微观界面处引发多层剥落空洞的成核。非均匀传播反射波相遇产生的拉伸应力分布不均匀,导致微观界面处多层剥落空洞的分布不均匀。第二相晶粒导致的位错密度增加阻碍了纳米晶双相钛合金中二次空洞的形核,从而造成了纳米晶单相钛合金与纳米晶双相钛合金在二次空洞形核方面的差异。在剥落阶段的损伤率(D˙)与冲击阶段的应变率(ε˙)呈正相关,并遵循关系式:D˙=aε˙b(a 和 b 为拟合参数,与材料的微观结构和冲击条件有关)。尽管冲击速度增加,但纳米晶钛合金中仍会在微观界面处形核多个空洞,并发生晶间剥落。


Thin-Walled Structures

Underwater acoustic simulation from multi-view sonar images: A NeuS-assisted boundary element approach

Haojie Lian, Shiwei Li, Xinhao Li, Yanming Xu, Leilei Chen, Sundararajan Natarajan

doi:10.1016/j.tws.2025.114180

多视点声纳图像的水声模拟:news辅助边界元方法

This paper presents a novel approach that integrates neural surface reconstruction from multi-view sonar images with boundary element methods based on subdivision surfaces, to establish a reverse engineering pipeline for acoustic simulation. Traditional acoustic simulations in reverse engineering often rely on high-fidelity geometric models, which are challenging to obtain in underwater environments. To address this, we leverage neural surface reconstruction to recover a high-quality implicit surface representation from sparse and noisy multi-view sonar images. The reconstructed surface is then converted into a Loop-scheme subdivision surface model, enabling s mooth integration with boundary element an alysis for efficient and accurate acoustic wave propagation simulations. Besides, the fast multipole algorithm is employed to accelerate boundary element ana lysis. Our method eliminates the need for manual model generation and enhances numerical accuracy in acoustic computations for reverse engineering applications. Numerical experimental results demonstrate the effectiveness of our approach in generating realistic acoustic fields from sonar-derived geometries, showcasing its potential for applications in underwater construction, structural inspection, and robotic perception.

本文提出了一种将多视点声纳图像的神经表面重构与基于细分曲面的边界元方法相结合的方法,建立声纳仿真的逆向工程管道。传统的逆向工程声学模拟往往依赖于高保真的几何模型,这在水下环境中很难获得。为了解决这个问题,我们利用神经表面重建从稀疏和噪声多视点声纳图像中恢复高质量的隐式表面表示。然后将重建表面转换为环方案细分表面模型,使边界元分析能够顺利集成,从而实现高效准确的声波传播模拟。此外,采用快速多极子算法加速边界元分析。该方法消除了人工模型生成的需要,提高了逆向工程声学计算的数值精度。数值实验结果证明了我们的方法在从声纳导出的几何形状产生真实声场方面的有效性,展示了它在水下建筑、结构检测和机器人感知方面的应用潜力。


Experimental studies on the flexural behavior of lipped cellular beams with punched circular web openings

Feng Xu, Xiao-Hong Han, Zhe Yuan, Yang Dong, Lian-Guang Jia

doi:10.1016/j.tws.2025.114182

带穿孔圆腹板开口的唇形蜂窝梁受弯性能试验研究

To address the issue of web buckling around the weakened openings in cellular beams, conventional reinforcement methods typically employ transverse stiffeners. However, this approach increases steel consumption and introduces welding-induced residual stresses, thereby impairing structural performance. In this study, a novel cellular beam, termed the lipped cellular beam with punched circular web openings (LCB), is proposed to overcome these drawbacks. Experimental tests were conducted on five specimens, including conventional cellular beam (CB) and LCBs, complemented by finite element simulations using ABAQUS. The results show that the introduction of lips reduces plastic deformation, increases the ultimate load capacity by approximately 26%, and enhances displacement ductility by around 20%. Parametric an alysis further indicates that the local stability of the web in LCBs is strongly affected by the opening ratio(ρ) and web thickness(tw), while the flexural capacity is mainly governed by tw. Based on the findings, design recommendations are proposed: the height-to-thickness ratio of tee-section (α) should be no less than 25; the opening spacing (s) should be taken as the larger of 50 mm or the value corresponding to a width-to-thickness ratio of the web-post (β) not s maller than α.

为解决蜂窝梁中削弱开口周围出现的腹板屈曲问题,传统加固方法通常采用横向加劲肋。然而,这种方法 会增加钢材用量,并引入焊接残余应力,从而降低结构性能。本研究提出了一种新型蜂窝梁,称为带冲孔圆孔腹板的带翼蜂窝梁(LCB),以克服这些缺陷。对包括传统蜂窝梁(CB)和 LCB 在内的五个试件进行了实验测试,并使用 ABAQUS 进行了有限元模拟。结果表明,翼缘的引入减少了塑性变形,极限承载力提高了约 26%,位移延性提高了约 20%。参数分析进一步表明,LCB 腹板的局部稳定性主要受开口率(ρ)和腹板厚度(tw)的影响,而弯曲承载力主要由 tw 决定。基于这些发现,提出了设计建议:T 型截面的高度与厚度之比(α)应不小于 25;开口间距(s)应取 50 毫米与腹板柱(β)宽厚比不小于α所对应的值中的较大者。


Novel S-shaped re-entrant honeycomb metamaterial with improved crashworthiness through reduced stress concentration

Liu Rong, Zhong Yifeng, Poh Leong Hien, Tang Yuxin

doi:10.1016/j.tws.2025.114188

新型s形再入式蜂窝超材料,通过降低应力集中提高耐撞性

Traditional auxetic re-entrant honeycombs (ARH) are characterized by significant stress concentration at the sharp angles between inclined and horizontal struts, reducing their load-bearing capacity and crashworthiness. To optimize their mechanical properties, this study proposes a novel S-shaped re-entrant honeycomb (SRH) design by replacing the sharp angles with S-shaped transitions. The quasi-static compression performance of the SRH structure was systematically investigated through experimental tests, 3D FE modeling (3D-FEM), 3D equivalent Cauchy modeling (3D-ECM), and theoretical plateau stress model. Compared to the ARH, the SRH structure effectively delays the transition to the plateau stage, reduces stress concentration by 59.2%. The S-shaped transition in SRH prevents premature densification induced by localized strut buckling. Moreover, a larger transition radius promotes a distinct dual-plateau behavior and introduces additional plastic hinges, achieving a remarkable increase in energy absorption and specific energy absorption (SEA). The densification stage of the SRH also exhibits more uniform deformation with a reduced fracture zone. The parametric study indicates that the maximum SEA is obtained at a radius-to-thickness ratio (λ) of 1 and a height-to-width ratio (γ) of 8/12. Increasing the strut thickness-to-depth ratio (μ) enhances plateau load-bearing capacity, resulting in a 240% increase in the mean crash stress (MCS). These findings offer a novel design strategy and a reliable predictive framework for applications demanding lightweight structures with superior crashworthiness.

传统的反向蜂窝结构(ARH)由于倾斜和水平支柱之间锐角处存在显著的应力集中,导致其承载能力和抗冲击性能降低。为了优化其机械性能,本研究提出了一种新型的 S 形反向蜂窝(SRH)设计,通过用 S 形过渡取代锐角来实现。通过实验测试、三维有限元建模(3D-FEM)、三维等效柯西建模(3D-ECM)和理论平台应力模型,对 SRH 结构的准静态压缩性能进行了系统研究。与 ARH 相比,SRH 结构有效地推迟了进入平台阶段的时间,应力集中降低了 59.2%。SRH 中的 S 形过渡可防止局部支柱屈曲引起的过早致密化。此外,较大的过渡半径促进了明显的双平台行为,并引入了额外的塑性铰链,从而显著提高了能量吸收和比能量吸收(SEA)。SRH 的致密化阶段也表现出更均匀的变形,且断裂区减小。参数研究结果表明,在半径与厚度比(λ)为 1 以及高度与宽度比(γ)为 8/12 时,SEA 达到最大值。增加支柱厚度与深度比(μ)可增强平台承载能力,使平均碰撞应力(MCS)提高 240%。这些发现为需要轻质且具有卓越抗撞性结构的应用提供了新颖的设计策略和可靠的预测框架。




来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemAbaqusDeform断裂碰撞建筑声学焊接理论材料机器人分子动力学试验
著作权归作者所有,欢迎分享,未经许可,不得转载
首次发布时间:2025-11-12
最近编辑:8小时前
Tansu
签名征集中
获赞 12粉丝 6文章 948课程 0
点赞
收藏
作者推荐

【新文速递】2025年9月26日复合材料SCI期刊最新文章

今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 2 篇Composite StructuresAn alytical modeling of cantilever bistable composites with slit cutoutsKarthik Boddapati, Andres F. Arrietadoi:10.1016/j.compstruct.2025.119672具有狭缝切口的悬臂双稳复合材料的解析建模Bistable composite laminates have been widely studied for morphing applications due to the large shape and stiffness change between their stable equilibrium states. However, these types of composites tend to lose their bistable behavior at low aspect ratios (length/width) when constrained in a cantilever configuration. To address this, a novel design introducing slit cutouts into cantilever laminates has been proposed, enabling bistability even in low aspect ratio geometries and significantly expanding their design space. The design of such slitted laminates requires the use of computationally intensive simulations to optimize the size and location of the slit cutouts, and to study their influence on the laminate’s behavior. In this work, we present an an alytical model to predict the stable states and stiffness properties of multi-sectioned bistable laminates with slit cutouts, clamped along a single edge, from a symbolically calculated, parametric strain energy expression. A special discretization of the laminate’s geometry is utilized to account for the slit cutouts, and the Rayleigh–Ritz method using polynomial displacement shape functions is employed to approximate the two stable configurations of the laminates. The developed model is further used to predict the stiffness of the laminate’s stable states under concentrated forces and uniform pressure loads. The results from the model are validated against finite element simulations as well as experimental measurements. Finally, the utility of the an alytical model in designing low aspect ratio bistable laminates is demonstrated through a parametric study. The presented model enables the efficient design and an alysis of slitted bistable composites embeddable within larger compliant structures.由于双稳态复合材料层合板在稳定平衡状态之间具有较大的形状和刚度变化,因此在变形应用方面得到了广泛的研究。然而,当受到悬臂结构的约束时,这些类型的复合材料在低纵横比(长/宽)下往往会失去其双稳态行为。为了解决这个问题,一种新颖的设计提出了在悬臂层压板中引入狭缝切割,即使在低纵横比几何形状下也能实现双稳定性,并显着扩大了其设计空间。这种开缝层压板的设计需要使用密集的计算模拟来优化开缝切口的尺寸和位置,并研究它们对层压板性能的影响。在这项工作中,我们提出了一个解析模型来预测具有狭缝切口的多截面双稳态层压板的稳定状态和刚度特性,沿着单个边缘夹紧,从符号计算的参数应变能表达式。利用层合板几何的特殊离散化来考虑狭缝切割,并使用多项式位移形状函数的瑞利-里兹方法来近似层合板的两种稳定构型。利用所建立的模型进一步预测了层合板在集中力和均压载荷作用下稳定状态的刚度。通过有限元仿真和实验测量验证了模型的正确性。最后,通过参数化研究证明了该分析模型在低纵横比双稳态层合板设计中的实用性。该模型能够有效地设计和分析可嵌入更大柔性结构的劈裂双稳复合材料。Composites Part A: Applied Science and ManufacturingOrientation effects on the damage tolerance of carbon nanotube-reinforced aluminum compositesHan Zhu, Zengqian Liu, Xiaonan Li, Hanzhong Liu, Xuegang Wang, Jiapeng Hou, Zhenyu Liu, Bolv Xiao, Zongyi Ma, Zhefeng Zhangdoi:10.1016/j.compositesa.2025.109320取向对碳纳米管增强铝复合材料损伤容限的影响Carbon nanotube (CNT)-reinforced aluminum matrix composites have attracted significant attention due to their promising properties. Fracture toughness and impact toughness are essential for their use in structural applications. In this study, CNT-reinforced 2009Al alloy composites with varying CNT contents were fabricated, and their microstructure, nanoindentation and tensile properties, fracture toughness, and impact toughness were systematically characterized and compared with those of CNT-free alloy. The results reveal anisotropic structural characteristics of the composites across multiple length scales, leading to pronounced mechanical anisotropy, with properties along the extrusion direction markedly surpassing those along the transverse direction. The increase in CNT content leads to enhanced nanoindentation hardness, reduced modulus, and tensile strength, but results in a compromise in plasticity and toughness. The mechanical properties were ana lyzed in relation to the microstructures and microscopic fracture characteristics. This study is expected to offer insights for the structural applications and component design of CNT-reinforced aluminum matrix composites.碳纳米管增强铝基复合材料因其具有良好的性能而备受关注。断裂韧性和冲击韧性是它们在结构应用中必不可少的。本研究制备了不同碳纳米管含量的碳纳米管增强2009Al合金复合材料,系统表征了其显微组织、纳米压痕和拉伸性能、断裂韧性和冲击韧性,并与无碳纳米管合金进行了比较。结果表明,复合材料在多个长度尺度上具有各向异性的结构特征,导致了明显的力学各向异性,挤压方向的性能明显优于横向的性能。碳纳米管含量的增加导致纳米压痕硬度的提高,模量和抗拉强度的降低,但导致塑性和韧性的妥协。从微观组织和断口特征等方面分析了材料的力学性能。该研究有望为碳纳米管增强铝基复合材料的结构应用和部件设计提供见解。Microstructure-driven hydrogen permeability in thin-ply thermoplastic composites: Insights for Type V storage tanksF.E. Oz, A. Wagih, B. Joarder, S.J. Datta, M. Eddaoudi, G. Lubineaudoi:10.1016/j.compositesa.2025.109316 薄层热塑性复合材料中微结构驱动的氢渗透性:对V型储罐的见解The potential of thermoplastic composites for gas storage in Type V tanks remains to be fully assessed. Yet, we demonstrate for thin-ply carbon fiber-reinforced polyamide 6 (CF/PA6) composites a strong dependence of the hydrogen permeability to their microstructure. Cross-ply laminates with layer thicknesses of 42 μm, 84 μm, and 168 μm were tested under hydrogen feed pressures of 5, 10, and 15 bar in pristine and pre-damaged states, induced by tensile loading to 60%–80% of ultimate strength. In pristine condition, thin-layer laminates exhibited higher permeability due to lower crystallinity, greater amorphous content, and lower flexural modulus. Thick-layer laminates, with larger crystalline domains, developed more tortuous diffusion paths leading to lower permeability. Increasing pressure decreased permeability through hydrogen-induced crystallization. Thin layers sustained early damage, maintaining consistent damage content at high strains, ensuring allowable permeability, while thick layers resisted initial damage but degraded at high strains, increasing permeability significantly. The findings highlight the impact of microstructure on hydrogen transport and provide key design insights for safe hydrogen storage in Type V tanks using thin-ply CF/PA6 composites.用于 V 型储罐的气体储存的热塑性复合材料的潜力仍有待全面评估。然而,我们证明了对于薄层碳纤维增强聚酰胺 6(CF/PA6)复合材料,其氢渗透性与其微观结构有很强的依赖性。在 5、10 和 15 巴的氢气进料压力下,对层厚分别为 42 微米、84 微米和 168 微米的正交层压板进行了测试,测试状态包括原始状态和通过拉伸加载至极限强度的 60% - 80% 而产生的预损伤状态。在原始状态下,薄层层压板由于结晶度较低、无定形含量较高以及弯曲模量较低而表现出更高的渗透性。厚层层压板具有更大的结晶域,形成了更曲折的扩散路径,从而导致渗透性更低。压力的增加通过氢诱导结晶降低了渗透性。薄层在早期就出现损伤,在高应变下保持稳定的损伤含量,从而确保了允许的渗透性,而厚层则在初始阶段抵抗损伤,但在高应变下性能下降,渗透性显著增加。这些发现突显了微观结构对氢气传输的影响,并为使用薄层碳纤维/尼龙 6 复合材料在 V 型储罐中安全储存氢气提供了关键的设计见解。Composites Part B: EngineeringData-Driven Surface Temperature Prediction for Variable Tool Geometries in Automated Fiber PlacementMatthew Godbold, Ben Francis, Ramy Harik, Erin Anderson, Dawn Jegleydoi:10.1016/j.composites b.2025.113047自动化纤维铺放中可变刀具几何形状的数据驱动表面温度预测Accurate surface temperature prediction is critical for ensuring quality control and process optimization in automated fiber placement (AFP). While traditional heat transfer modeling approaches rely on finite element ana lysis (FEA) and numerical methods, they often struggle to generalize across different tool geometries and heating mechanis ms because they are typically tailored to specific conditions and require substantial reformulation when conditions change. This study introduces a data-driven modeling approach to predict applied surface temperature during AFP layup. A polynomial regression model was developed using experimental data collected from infrared (IR) and pulsed light (PL) heating systems across various processing parameters, including heater power, layup speed, distance-to-surface, and p-angle (AFP end-effector head tilt relative to the nip-point). A 10-fold cross-validation demonstrated strong predictive accuracy, yielding coefficient of determination, , values of and for the IR and PL models, respectively. A manufacturing case study further demonstrated the ability of the model to predict temperature variations across flat and complex tool surfaces, while flux knockdown experiments were used to quantify temperature distribution effects. Experimental validation using thermocouple measurements confirmed the accuracy of the model in predicting surface temperature, with a mean percent error of , highlighting the model’s potential for real-time AFP process monitoring. While the model effectively captures key thermal behaviors, future work will focus on incorporating two- and three-dimensional thermal effects, integrating physics-based modeling, and expanding validation to laser-assisted AFP heating. This research advances machine learning-driven heat transfer modeling in AFP, paving the way for intelligent composite manufacturing.准确的表面温度预测是确保自动铺布(AFP)质量控制和工艺优化的关键。虽然传统的传热建模方法依赖于有限元分析(FEA)和数值方法,但它们往往难以推广到不同的刀具几何形状和加热机制,因为它们通常是针对特定条件量身定制的,并且当条件发生变化时需要进行大量的重新制定。本研究介绍了一种数据驱动的建模方法来预测AFP铺设过程中的应用表面温度。利用从红外(IR)和脉冲光(PL)加热系统中收集的实验数据,建立了一个多项式回归模型,该模型涉及各种加工参数,包括加热器功率、铺层速度、与表面的距离和p角(AFP末端执行器头部相对于夹点的倾斜度)。10倍交叉验证表明,IR和PL模型的预测精度、决定屈服系数和值都很强。一个制造案例研究进一步证明了该模型预测平面和复杂刀具表面温度变化的能力,而通量击倒实验用于量化温度分布效应。使用热电偶测量的实验验证证实了该模型在预测表面温度方面的准确性,平均误差为,突出了该模型在AFP过程实时监测方面的潜力。虽然该模型有效地捕获了关键的热行为,但未来的工作将集中在结合二维和三维热效应,集成基于物理的建模,并将验证扩展到激光辅助AFP加热。该研究推进了机器学习驱动的AFP传热建模,为智能复合材料制造铺平了道路。Cross-Scale Simulation-Driven Design of rGO-PFAN/Epoxy Coatings: Synergistic Physical Barrier-Chemical Repulsion for Superior Moisture ResistanceXiang Li, Yanji Zhu, Yue Sun, Dan Lin, Huaiyuan Wangdoi:10.1016/j.composites b.2025.113011 rGO-PFAN/环氧涂料的跨尺度模拟驱动设计:物理屏障-化学斥力协同抗湿性In harsh humid environments, conventional epoxy coatings suffer from inadequate corrosion resistance due to microporous defects formed during curing, while the trial-and-error optimization of fillers faces challenges such as unclear mechanis ms and low design efficiency. This study proposes a novel "computation-driven material design" paradigm, elucidating the synergistic moisture-resistant mechanis ms of fillers through cross-scale simulations. Molecular dynamics (MD) simulations show that adding 3 wt% graphene oxide (GO) reduces the free volume of epoxy by 15% and decreases the water diffusion coefficient by 10%. Density functional theory (DFT) calculations identify a high adsorption energy barrier (21.831 eV) generated by fluorine groups in polyfluoroaniline (PFAN) through electron cloud redistribution, effectively suppressing water penetration. Monte Carlo (MC) simulations further bridge microscopic energy barriers with macroscopic penetration flux. Guided by these insights, reduced graphene oxide-polyfluoroaniline (rGO-PFAN) composite fillers are synthesized via covalent grafting, experimentally demonstrating synergistic barrier-hydrophobic effects. Epoxy coatings containing 1.5 wt% rGO-PFAN retain an impedance modulus of 4.44×1011 Ω·cm2 after 90-day immersion, while 2 wt% filler reduces long-term water absorption by 73.63%. Salt spray tests confirm superior corrosion suppression at defect regions. Mechanical property tests show that the coating exhibits significantly reduced wear loss, enhanced adhesion strength, and perfect adhesion after thermal cycling. This work pioneers the multiscale correlation from electron-cloud interactions to macroscopic anticorrosion performance, establishing a theoretical framework for the rational design of intelligent coatings in extreme environments.在恶劣的潮湿环境下,传统的环氧涂料由于固化过程中形成微孔缺陷,其耐腐蚀性不足,而填料的试错优化则面临着机理不明确、设计效率低等挑战。本研究提出了一种新的“计算驱动的材料设计”范式,通过跨尺度模拟阐明了填料的协同抗湿机制。分子动力学(MD)模拟表明,添加3 wt%的氧化石墨烯(GO)可使环氧树脂的自由体积减少15%,水扩散系数降低10%。密度泛函理论(DFT)计算发现,聚氟苯胺(PFAN)中的氟基团通过电子云重分布产生了较高的吸附能垒(21.831 eV),有效抑制了水的渗透。蒙特卡罗(MC)模拟进一步用宏观穿透通量架起了微观能垒的桥梁。在这些见解的指导下,通过共价接枝合成了还原氧化石墨烯-聚氟苯胺(rGO-PFAN)复合填料,实验证明了协同疏水屏障效应。含有1.5 wt% rGO-PFAN的环氧涂料在浸泡90天后仍能保持4.44×1011 Ω·cm2的阻抗模量,而含有2 wt% rGO-PFAN的环氧涂料可使长期吸水率降低73.63%。盐雾试验证实在缺陷区域具有较好的耐蚀性。力学性能测试表明,热循环后涂层磨损明显减少,附着力增强,附着力良好。这项工作开创了从电子云相互作用到宏观防腐性能的多尺度关联,为极端环境下智能涂层的合理设计建立了理论框架。Load-bearing capacity improvement and failure mechanis ms of integrated multi-cell sandwich hybrid tube under lateral deformationYunfei Peng, Maojun Li, Xujing Yang, Jinlei Liu, Bingjie Sun, Tian Liudoi:10.1016/j.composites b.2025.113045横向变形作用下集成多单元夹芯复合管承载力提升及破坏机制研究In this study, an integrated multi-cell sandwich hybrid (MCSH) tube with foam filling and localized thickness enhancement is proposed and fabricated using an internal thermal expansion forming process. Systematic three-point bending and lateral compression tests reveal that increasing the number of internal cells significantly enhances the load-bearing capacity and failure stability, achieving a desirable balance between stiffness and toughness. Under three-point bending, the triple-cell sandwich hybrid (TCSH) tube exhibits a structural stiffness of 4.2 kN/mm and crush force efficiency (CFE) of 96.22 %, surpassing most previously reported structures. Finite element simulations further indicate that the multi-rib design activates the responses of both the top and bottom flanges, forming symmetric shear paths and establishing a multi-path load transfer mechanis m. The MCSH tube demonstrates a combination of high stiffness, superior energy absorption (EA), and structural lightweighting. The rib structure effectively alleviates stress concentration, delays interfacial debonding and shell buckling, and promotes a transition from localized failure to multi-stage progressive damage mode. The MCSH tube exhibits outstanding performance in terms of load-bearing, specific energy absorption, damage delay, and lightweight design, offering theoretical foundations and design insights for high-performance composite structures in protection, transportation, and aerospace applications.在本研究中,提出了一种具有泡沫填充和局部增厚的集成多单元三明治混合管(MCSH),并采用内部热膨胀成形工艺制作。系统的三点弯曲和侧压试验表明,增加内部单元的数量显著提高了承载能力和破坏稳定性,实现了刚度和韧性之间的理想平衡。在三点弯曲条件下,三室夹层混合材料(TCSH)管的结构刚度为4.2 kN/mm,挤压力效率(CFE)为96.22%,超过了之前报道的大多数结构。有限元模拟进一步表明,多肋设计激活了上下翼缘的响应,形成对称剪切路径,建立了多径荷载传递机制。MCSH管具有高刚度、优越的能量吸收(EA)和结构轻量化的特点。肋结构有效地缓解了应力集中,延缓了界面剥离和壳体屈曲,促进了局部破坏向多级递进破坏模式的转变。MCSH管在承载、比能吸收、损伤延迟和轻量化设计方面表现出色,为高性能复合材料结构在防护、运输和航空航天领域的应用提供了理论基础和设计见解。Time-dependent thermo-elastic creep response of rotating thick cylindrical shells made of axially functionally graded materials based on the TSDTTahereh Taghizadeh, Mohammad Zamani Nejaddoi:10.1016/j.composites b.2025.113046基于TSDT的轴向功能梯度材料厚圆柱壳旋转时热弹性蠕变响应This paper presents an ana lytical study on the time-dependent thermo-mechanical creep behavior of rotating thick cylindrical shells made of functionally graded materials (FGMs) with axial gradation. These structures are widely used in aerospace, nuclear, pressure vessels, and mechanical systems subjected to extreme thermal and mechanical environments where creep significantly affects long-term performance. Notably, the creep behavior of FGMs with axial variation has not been previously investigated. The third-order shear deformation theory (TSDT) is employed to model the structure, providing greater accuracy than classical and first-order shear deformation theory (FSDT), especially for thick shells. To the best of the authors’ knowledge, TSDT has not been applied to an alyze creep behavior before, marking a significant novelty of this work. Except for Poisson’s ratio, all thermal and mechanical characteristics of the material vary gradually along the cylinder’s axis based on a power-law model. The governing equations are derived using the principle of minimum total potential energy, resulting in a system of variable-coefficient nonhomogeneous differential equations. These equations are solved an alytically via a multi-layered method (MLM), which transforms them into homogeneous equations with constant coefficients in each layer, enhancing accuracy over numerical or approximate methods. The creep behavior is modeled using Norton’s law, and an iterative procedure is adopted to obtain time-dependent stress and displacement distributions. The ana lysis includes the effects of axial gradation, temperature gradients, internal pressure, and rotational forces. Results are validated against the finite element method (FEM), showing excellent agreement.本文对具有轴向梯度的功能梯度材料(fgm)厚圆柱壳旋转时的热-机械蠕变行为进行了分析研究。这些结构广泛应用于航空航天、核、压力容器和经受极端热、机械环境的机械系统,在这些环境中,蠕变会显著影响其长期性能。值得注意的是,以前没有研究过轴向变化的fgm的蠕变行为。采用三阶剪切变形理论(TSDT)对结构进行建模,具有比经典和一阶剪切变形理论(FSDT)更高的精度,尤其适用于厚壳。据作者所知,TSDT还没有被应用于分析蠕变行为,这标志着这项工作的一个重要的新颖性。除泊松比外,材料的所有热学和力学特性都根据幂律模型沿圆柱体轴线逐渐变化。利用最小总势能原理推导出控制方程,得到变系数非齐次微分方程组。这些方程通过多层方法(MLM)解析求解,将其转化为每层常系数的齐次方程,提高了数值方法或近似方法的精度。采用诺顿定律对蠕变行为进行建模,并采用迭代法获得随时间变化的应力和位移分布。分析包括轴向梯度、温度梯度、内压和旋转力的影响。结果与有限元法(FEM)进行了验证,结果吻合良好。Composites Science and TechnologyEnhanced dielectric and energy storage performance of polyetherimide doping with molecular semiconductor all-organic compositesMingyang Zhang, Likun Zang, Hui Tong, Fuyuan Liudoi:10.1016/j.compscitech.2025.111391 聚醚酰亚胺掺杂分子半导体全有机复合材料提高介电和储能性能Polyetherimide (PEI), as a kind of high-temperature dielectrics, still face the issue of current leakage under thermo-electrical coupling fields, leading to a sharp degradation of energy storage performance. In this study, an intrinsic PEI with superior comprehensive properties was synthesized using 4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) and 2,2-bis[4-(4-aminophenoxy)phenyl] propane (BAPP). Through molecular design, an "electron gate" mechanis m was introduced via σ-π hyperconjugation effects, effectively suppressing long-range charge delocalization. The resulting intrinsic PEI achieves an energy storage density (Ud) of 1.93 J/cm3 at 150 °C, which is 20.6% higher than that of commercial Ultem™ PEI film (1.6 J/cm3). Further modification was conducted by doping with three molecular semiconductors: 3,4,9,10-perylenetetracarboxylic diimide (PTCDI), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), and 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). Density Functional Theory (DFT) simulations and Low-Energy Inverse Photoemission Spectroscopy (LEIPS) experiments reveal that all three semiconductors exhibit higher electron affinity than the intrinsic PEI. Additionally, Thermally Stimulated Depolarization Current (TSDC) reveals that the incorporation of molecular semiconductors increases trapped charges and trap energy level compared to intrinsic PEI. Both experimental and simulation results consistently demonstrate that molecular semiconductor doping can enhance energy storage performance by constructing deep trap sites within the PEI matrix. Experimental results demonstrate that at 150 °C, the 0.125% PTCDI-doped PEI achieves a breakdown strength of 545 MV/m, an Ud of 3.71 J/cm3, and a charge-discharge efficiency (η) of 90.13% (vs. 436 MV/m, 1.93 J/cm3, and 94.67% for intrinsic PEI). This research provides an effective strategy for improving the capacitive performance of polymer dielectrics under thermo-electrical coupling conditions.聚醚酰亚胺(PEI)作为一种高温电介质,仍面临在热电耦合场下电流泄漏的问题,导致其储能性能急剧下降。在本研究中,通过使用 4,4'-(4,4'-异丙叉二苯氧基)双(邻苯二甲酸酐)(BPADA)和 2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)合成了具有优越综合性能的本征 PEI。通过分子设计,利用 σ-π 超共轭效应引入了“电子门”机制,有效抑制了长程电荷离域。所得本征 PEI 在 150°C 时的储能密度(Ud)达到 1.93 J/cm³,比商用 Ultem™ PEI 薄膜(1.6 J/cm³)高 20.6%。进一步通过掺杂三种分子半导体:3,4,9,10-苝四甲酸二酰亚胺(PTCDI)、1,4,5,8-萘四甲酸二酐(NTCDA)和 3,4,9,10-苝四甲酸二酐(PTCDA)进行了改性。密度泛函理论(DFT)模拟和低能反向光电子能谱(LEIPS)实验表明,这三种半导体的电子亲和力均高于本征聚醚酰亚胺(PEI)。此外,热刺 激去极化电流(TSDC)表明,分子半导体的掺入增加了与本征 PEI 相比的陷阱电荷和陷阱能级。实验和模拟结果均一致表明,分子半导体掺杂可通过在 PEI 基质中构建深陷阱位点来提高能量存储性能。实验结果表明,在 150°C 时,掺杂 0.125% 的 PTCDI 的 PEI 达到了 545 MV/m 的击穿强度、3.71 J/cm³ 的 Ud 和 90.13% 的充放电效率(而本征 PEI 分别为 436 MV/m、1.93 J/cm³ 和 94.67%)。这项研究为在热电耦合条件下提高聚合物电介质的电容性能提供了一种有效策略。Continuous construction of gradient modulus interphase in CF/PA6 composites with enhanced interfacial properties and reduced porosityGuang Yang, Jinze Cui, Kewen Zeng, Yutai Luo, Feng Bao, Jiali Yu, Caizhen Zhu, Jian Xu, Huichao Liudoi:10.1016/j.compscitech.2025.111392 CF/PA6复合材料中梯度模量界面相的连续构建增强了界面性能并降低了孔隙率Chopped ultra-thin carbon fiber tape reinforced polyamide 6 (PA6) composites are considered promising materials for balancing the mechanical properties and ease of processing, particularly due to their in-plane quasi-isotropy, which facilitates structural design and manufacturing in the industry. However, further advancement is hindered by the weak interfacial bonding and modulus mis match between CF and PA6 matrix, as well as high porosity of the CF/PA6 composites. In this work, plas ma treatment and mixed COOH-CNTs/PA6 sizing methods were proposed to enhance the surface roughness (Ra) and surface energy of the CF. Compared to untreated CF, the Ra value and surface energy of the modified CF increased by 45.1 % and 69.7 %, respectively. After 0.6 wt.% COOH-CNTs modification, the tensile strength, Young’s modulus, and interlaminar shear strength (ILSS) of the composites reaches 900.0 MPa, 48.4 GPa, and 62.3 MPa, which is respectively 24.9 %, 19.8 %, and 36.9 % higher than that of the unmodified composites. In particular, the porosity was reduced to 1.22 %, which was 73.3 % lower than that of unmodified composites. Moreover, the p-CF@0.6 wt.% CNT/PA6 composites exhibited mitigatory modulus gradient across the interphase. This work synergistically enhances the interface adhesion and reduces the porosity of the CF/PA6 composites via a large-scale continuous modification technology.短切超薄碳纤维带增强聚酰胺6 (PA6)复合材料被认为是一种很有前途的材料,因为它具有平衡机械性能和易于加工的特点,特别是由于其面内准各向同性,这有利于工业上的结构设计和制造。然而,CF/PA6复合材料的界面结合较弱,模量不匹配,以及CF/PA6复合材料的高孔隙率阻碍了进一步的发展。本研究提出了等离子体处理和COOH-CNTs/PA6混合上浆方法来提高CF的表面粗糙度(Ra)和表面能。与未经处理的CF相比,改性CF的Ra值和表面能分别提高了45.1%和69.7%。经0.6 wt.% COOH-CNTs改性后,复合材料的抗拉强度、杨氏模量和层间剪切强度(ILSS)分别达到900.0 MPa、48.4 GPa和62.3 MPa,比未改性的复合材料分别提高24.9%、19.8%和36.9%。特别是孔隙率降低到1.22%,比未改性的复合材料降低了73.3%。此外,p-CF@0.6 wt.% CNT/PA6复合材料在界面上表现出减缓模量梯度。本工作通过大规模连续改性技术,协同增强了CF/PA6复合材料的界面附着力,降低了其孔隙率。 来源:复合材料力学仿真Composites FEM

未登录
还没有评论
课程
培训
服务
行家
VIP会员 学习计划 福利任务
下载APP
联系我们
帮助与反馈