今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 2 篇
Simultaneous optimization of composite shells, metallic components and their Joints
Konrad Schneider, Olaf Ambrozkiewicz, Benedikt Krieges mann
doi:10.1016/j.compstruct.2025.119796
复合材料壳体、金属构件及其接头的同步优化
This paper presents an approach for the simultaneous topology optimization of an isotropic (for instance metallic) part, the layup optimization of a composite part, and the search for the optimized position of joints between the parts. Within a gradient-based optimization, a failure criterion for the composite acts as a constraint. The constraint’s gradients with respect to fiber orientations, pseudo densities of the isotropic elements, and joint positions are presented. As an example, the load introduction into an isotropic component that is attached to a composite plate is shown. The results show a significant influence of the considered constraint on the optimized overall design.
本文提出了一种同时求解各向同性(如金属)零件拓扑优化、复合材料零件分层优化和零件间连接优化位置的方法。在基于梯度的优化中,复合材料的失效准则充当约束。给出了约束的梯度与纤维取向、各向同性元件的拟密度和接头位置的关系。作为一个例子,载荷引入到各向同性组件,是附在一个复合板。结果表明,所考虑的约束条件对优化后的总体设计有显著影响。
Elastic-viscoplastic parameter identification for particle-reinforced composite under spherical indentation using SA-DVC enhanced FEMU
Bo Wang, Yanghong Zhao, Xianling Zheng, Xiangyu Du, Zhi Sun, Xu Guo
doi:10.1016/j.compositesa.2025.109411
基于SA-DVC增强FEMU的颗粒增强复合材料球形压痕弹粘塑性参数辨识
The elastic, plastic, and viscous properties of particle-reinforced polymer composites (PRPCs) serve as critical indicators for their mechanical behavior characterization and engineering applications. The indentation technique has gained prominence in assessing mechanical properties across various materials owing to its versatility and applicability. Moreover, the finite element model updating (FEMU) approach has been developed in conjunction with indentation techniques to elucidate elastoplastic properties, thereby providing insights for mechanical property optimization during material design. However, the commonly used load–displacement curve cannot capture the spatial distribution of deformation responses, thus limiting its ability to enhance the understanding of material properties and improve the calibration of constitutive models. In this study, an in-situ spherical indentation test was performed on a particle-reinforced polymer composite, integrated with X-ray micro-computed tomography (CT) imaging. A self-adaptive digital volume correlation (SA-DVC) approach was employed to measure the 4D spatiotemporal internal deformation fields. The elastic, plastic, and viscous parameters were identified with enhanced accuracy through enriching the cost function in the FEMU approach with the 4D deformation fields. The identification accuracy of typical elastic and viscous constitutive parameters was significantly improved, and the identification errors decreased by 11 % compared to the traditional identification method relying on the force–displacement curve. This work provides a framework capable of simultaneously identifying the elastic-viscoplastic parameters and reconstructing the internal viscous-plastic stress fields, facilitating a better understanding of the elastic–plastic and elastic-viscous networks in PRPCs.
颗粒增强聚合物复合材料(prpc)的弹性、塑性和粘性性能是其力学行为表征和工程应用的关键指标。由于其通用性和适用性,压痕技术在评估各种材料的机械性能方面取得了突出的成就。此外,有限元模型更新(FEMU)方法已与压痕技术相结合,用于阐明弹塑性特性,从而为材料设计过程中的力学性能优化提供见解。然而,常用的荷载-位移曲线无法捕捉变形响应的空间分布,从而限制了其增强对材料特性的理解和改进本构模型校准的能力。在这项研究中,对颗粒增强聚合物复合材料进行了原位球形压痕测试,并结合了x射线微计算机断层扫描(CT)成像。采用自适应数字体积相关(SA-DVC)方法测量了四维时空内部变形场。通过用四维变形场丰富FEMU方法中的代价函数,提高了识别弹性、塑性和粘性参数的精度。该方法显著提高了典型弹性和粘性本构参数的识别精度,与传统的基于力-位移曲线的识别方法相比,识别误差降低了11%。这项工作提供了一个能够同时识别弹粘塑性参数和重建内部粘塑性应力场的框架,有助于更好地理解prpc中的弹塑性和弹粘网络。
Self-powered flexible piezo-photoelectric dual-mode sensor based on PVDF-TrFE combined with MXene@TiO2 heterojunction
Miao Yang, Yuting Wang, Meiying Li, Baoyu Wang, Shouheng Sun, Chubin Wan, Xin Ju
doi:10.1016/j.composites b.2025.113161
基于PVDF-TrFE结合MXene@TiO2异质结的自供电柔性压电双模传感器
Conventional flexible sensors are often restricted to detecting a single type of physical stimulus, limiting their applicability in multimodal sensing environments. Herein, we present an optimized flexible PVDF-TrFE/MXene@TiO2(PMT) nanofiber-based dual-mode sensor that achieves breakthrough piezo-photoelectric performance. The sensor achieves a record-breaking UV sensitivity (1.72 μA mW-1) while operating completely without external power-harvesting energy solely from incident ultraviolet light, while maintains excellent linear response across 0.23-3.8 mW cm-2, demonstrating true self-sufficient operation. Most remarkably, the intensified piezoelectric polarization at the heterojunction interface critically enhances band bending, which drives exceptional device performance, yielding a 22.3-fold increase in output voltage (67 V) and nearly two orders of magnitude higher current (3.1 μA) compared to pure PVDF-TrFE under combined mechanical pressure and ultraviolet illumination. These exceptional characteristics stem from the judicious integration of the piezoelectric polymer with the photoactive heterostructure. This design not only enables efficient mechanical energy harvesting but also endows the system with superior optoelectronic detection capabilities, establishing an ideal platform for next-generation self-powered wearable optoelectronic systems.
传统的柔性传感器通常仅限于检测单一类型的物理刺 激,限制了它们在多模态传感环境中的适用性。在此,我们提出了一种优化的柔性PVDF-TrFE/MXene@TiO2(PMT)纳米纤维双模传感器,实现了突破性的压电光电性能。该传感器在完全没有外部电源的情况下实现了创纪录的紫外线灵敏度(1.72 μA mW-1),仅从入射紫外光中收集能量,同时在0.23-3.8 mW cm-2范围内保持良好的线性响应,展示了真正的自给自足运行。最显著的是,在机械压力和紫外线照射下,异质结界面处增强的压电极化极大地增强了带弯曲,从而驱动了优异的器件性能,输出电压(67 V)比纯PVDF-TrFE高22.3倍,电流(3.1 μA)比纯PVDF-TrFE高近两个数量级。这些特殊的特性源于压电聚合物与光活性异质结构的合理结合。该设计不仅实现了高效的机械能收集,还赋予了系统优越的光电检测能力,为下一代自供电可穿戴光电系统建立了理想的平台。
Comparison of Flexural Properties of Two Different CFRPs Before and After Low-velocity Impact: T1000 vs T300 Interleaved with Micro-/Nano- Aramid Fibers
Mingxin Ye, Yabin Deng, Yunsen Hu, Xiaozhi Hu
doi:10.1016/j.compscitech.2025.111428
T1000与T300与微/纳米芳纶纤维交织低速冲击前后两种不同cfrp抗弯性能的比较
T1000 carbon fibers are far superior to T300 fibers in tension, but the performance of bulk T1000 composites can be matched by bulk T300 composites interleaved with sparsely distributed micro-/nano- Aramid pulp (AP) fibers. In this study, we focus not only on the short-beam shear strength but also on the flexural strength of T1000 and T300-AP composites before and after impact, as these properties are critical indicators of structural performance under bending-dominated loading conditions. Maintaining the AP-epoxy interlayer thickness at 8 μm or less, with AP areal densities of 2, 4 and 6 gram/m2, leads to improvements of up to 38% in short-beam shear strength and 55% in flexural strength for the T300-AP composites, surpassing the performance of plain T1000 composites without such AP-interfacial toughening. These findings highlight the importance of interfacial design and quasi-Z-directional fiber bridging in CFRPs, demonstrating that resin-rich layers between carbon fiber plies as thin as 15 μm can be transformed into mechanically interlocked ply interfaces through AP-interfacial toughening, thereby bringing the structural performance of T300-AP composites to parity with that of T1000 composites.
T1000碳纤维在拉伸性能上远优于T300纤维,但块状T1000复合材料与稀疏分布的微/纳米芳纶纸浆(AP)纤维交织,其性能可以与块状T300复合材料相媲美。在本研究中,我们不仅关注了T1000和T300-AP复合材料的短梁抗剪强度,还关注了T1000和T300-AP复合材料在冲击前后的抗弯强度,因为这些性能是在弯曲主导载荷条件下结构性能的关键指标。当AP-环氧树脂层间厚度保持在8 μm以下,AP面密度分别为2、4和6 g /m2时,T300-AP复合材料的短束抗剪强度和抗弯强度分别提高了38%和55%,超过了未进行AP-界面增韧的普通T1000复合材料的性能。这些发现强调了界面设计和准z方向纤维桥接在cfrp中的重要性,表明薄至15 μm的碳纤维层之间的富树脂层可以通过ap -界面增韧转变为机械互锁的层界面,从而使T300-AP复合材料的结构性能与T1000复合材料相当。
Multiscale-Multiphysics Modeling of Moisture Absorption-induced Dielectric Evolution in Polymeric Composites
Partha Pratim Das, Vamsee Vadlamudi, Monjur Morshed Rabby, Ankur Jain, David Mollenhauer, Rassel Raihan
doi:10.1016/j.compscitech.2025.111433
聚合物复合材料吸湿诱导介电演化的多尺度多物理场模拟
This study presents a multiscale-multiphysics computational framework for modeling complex moisture absorption mechanis ms and its coupling with dielectric property evolution in polymer matrix composites (PMCs). First at the microscale level, orthotropic diffusion and absorption of water molecules, distinguishing between free and bound states respectively, are modeled using non-Fickian hindered diffusion model (HDM). The approach incorporates interphase effects and fiber-matrix heterogeneity utilizing finite element (FE) an alysis. Emphasis is placed on increased diffusivity and absorption properties of interphase regions and their impact on the transport and reaction kinetics through representative volumetric elements (RVEs). A homogenization scheme subsequently translates these microscale constituent properties to macroscale behavior, enabling efficient FE implementation. A novel multiphysics coupling then integrates the absorption model with Maxwell’s equations of electromagnetis m in order to mechanistically model moisture-induced electrical property changes, and orientational polarization effects through dipole moment redistribution. The developed models are validated using experimental gravimetric data and broadband dielectric spectroscopy (BbDS) measurements performed on unidirectional glass fiber reinforced polymer (GFRP) composites subjected to hygrothermal aging. Results demonstrate that HDM successfully models moisture absorption mechanis ms, e.g., diffusion, adsorption and desorption, while purely Fickian and irreversible binding models fail to match experimental trends. The coupled HDM-Maxwell model captures the correlation between experimentally observed moisture content and dielectric permittivity, where a ∼2.5 wt.% of moisture content resulted in ∼75% increase in dielectric permittivity. This coupled framework provides fundamental insights into the physics of moisture-electrical cross-property relationships in PMCs, while offering a validated an alytical tool for modeling multifunctional composite performance in humid environments.
本文提出了一个多尺度、多物理场的计算框架,用于模拟聚合物基复合材料的复杂吸湿机制及其与介电性能演变的耦合。首先,在微观尺度上,利用非菲克阻碍扩散模型(HDM)对水分子的正交各向异性扩散和吸收进行了建模,分别区分了自由态和束缚态。该方法结合了相间效应和利用有限元分析的纤维-基体非均质性。重点放在增加的扩散率和吸收性质的相间区域及其影响的运输和反应动力学通过代表性的体积元素(RVEs)。均匀化方案随后将这些微观尺度的成分属性转换为宏观尺度的行为,从而实现高效的FE实现。然后,一种新的多物理场耦合将吸收模型与麦克斯韦电磁学方程相结合,以机械地模拟水分引起的电学性质变化,以及通过偶极矩重分配产生的定向极化效应。通过对单向玻璃纤维增强聚合物(GFRP)复合材料进行湿热老化的实验重力数据和宽带介电光谱(BbDS)测量,验证了所开发的模型。结果表明,HDM模型成功地模拟了扩散、吸附和解吸等吸湿机制,而纯粹的菲克模型和不可逆结合模型不符合实验趋势。耦合HDM-Maxwell模型捕获了实验观察到的水分含量和介电常数之间的相关性,其中~ 2.5 wt.%的水分含量导致介电常数增加~ 75%。这种耦合框架为pmc中湿电交叉性能关系的物理特性提供了基本见解,同时为潮湿环境中多功能复合材料性能的建模提供了一种经过验证的分析工具。