今日更新:Composite Structures 4 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
A three-component volume coordinate system generalized mixed element for piezoelectric composite structures
Zhicheng Yong, Yanhong Liu, Weiming Guo, Guanghui Qing
doi:10.1016/j.compstruct.2025.119318
压电复合材料结构的三分量体积坐标系广义混合元
This paper combines the three-component volume coordinate system with the non-conforming generalized mixed element to develop an element for analyzing the static characteristics of piezoelectric composite structures. The element adopts volume coordinates as local coordinates, significantly alleviating the ill-conditioned relationship between local and Cartesian coordinates in traditional isoparametric elements under mesh distortion, thus reducing the sensitivity of the element to mesh distortion. Furthermore, the calculation of the Jacobian inverse matrix is avoided. On the other hand, this element retains the advantage of the mixed method that enables the concurrent consideration of displacement and stress boundary conditions, thereby facilitating an objective and rational description of the finite element model. Additionally, the discontinuity of in-plane stresses between layers is resolved by using a partial mixed method to separately solve the in-plane and out-of-plane stresses. Numerical examples demonstrate that the proposed element has excellent performance in the analysis of piezoelectric composite structures
本文将三分量体积坐标系与非协调广义混合单元相结合,建立了一种分析压电复合材料结构静力特性的单元。该单元采用体积坐标作为局部坐标,显著缓解了传统等参单元在网格畸变下局部坐标与笛卡尔坐标的病态关系,从而降低了单元对网格畸变的敏感性。进一步避免了雅可比矩阵逆矩阵的计算。另一方面,该单元保留了混合方法的优点,可以同时考虑位移和应力边界条件,从而便于对有限元模型进行客观合理的描述。此外,采用部分混合法分别求解层间面内应力和面外应力,解决了层间面内应力的不连续问题。数值算例表明,该单元在压电复合材料结构分析中具有良好的性能
Adjustable stiffness of chain mail fabrics
Miao Miao Yuan, Bo Hua Sun
doi:10.1016/j.compstruct.2025.119237
锁子甲织物的刚度可调
Adjustable stiffness chain mail fabrics, composed of interlocking 3D single-cell particles, attract significant interest for their flexibility, impact resistance, and controllable stiffness. This study aims to investigate the mechanical properties of in-vacuo chain mail fabric through a combination of experimental and numerical simulation methods. First, three different chain mail fabrics composed of various single-cell particles were produced. Subsequently, different external pressures were applied to the fabric to transform it into a load-bearing structure. Finally, three-point bending tests were conducted on the in-vacuo chain mail fabric, and numerical simulations were performed using the finite element software ABAQUS. The research shows that the apparent bending modulus, peak load, and energy absorption capacity of the in-vacuo chain mail fabric increase with the external pressure. When the external pressure reaches 64.5 kPa, the in-vacuo fabric’s apparent elastic bending modulus, peak load, and energy absorption capacity increase by 6 times, 16 times, and 15 times, respectively. Notably, when the three-dimensional particles is square, the in-vacuo fabric exhibits higher load-bearing capacity. Combining the experimental results and numerical simulation results show that the ”tensile contact” and ”compressive contact” between interlocking particles have a significant impact on the overall mechanical properties of the chain mail fabric.
由互锁的3D单细胞颗粒组成的可调刚度链甲织物因其灵活性、抗冲击性和可控刚度而引起了人们的极大兴趣。采用实验与数值模拟相结合的方法对真空锁子甲织物的力学性能进行了研究。首先,生产了三种不同的由不同单细胞粒子组成的锁子甲织物。随后,对织物施加不同的外部压力,使其转变为承重结构。最后,对真空锁子甲织物进行三点弯曲试验,并利用有限元软件ABAQUS进行数值模拟。研究表明,真空锁子甲织物的表观弯曲模量、峰值载荷和吸能能力随外部压力的增大而增大。当外界压力达到64.5 kPa时,真空织物的表观弹性弯曲模量、峰值载荷和能量吸收能力分别提高了6倍、16倍和15倍。值得注意的是,当三维粒子为正方形时,真空织物具有更高的承载能力。结合实验结果和数值模拟结果表明,联锁颗粒之间的“拉伸接触”和“压缩接触”对锁子甲织物的整体力学性能有显著影响。
Exploring the potential energy landscape of square bistable laminates bonded with piezoelectric macro fiber composites
Danish Bashir, P.M. Anikumar, B.N. Rao
doi:10.1016/j.compstruct.2025.119239
探讨压电宏纤维复合材料粘结方形双稳态层合板的势能格局
The concept of the asymmetric nature of a bistable composite laminate involves tailoring the potential energy landscape to achieve tunable behavior, which is crucial for optimizing its performance in various morphing and energy harvesting applications. A conventional square cross-ply laminate exhibits perfectly symmetric behavior with equal potential minima. The addition of smart materials, like piezoelectric macro fiber composite (MFC) actuators for morphing and energy harvesting applications, induces an asymmetric nature in the overall potential energy landscape of the resulting bistable-MFC structure. This asymmetric energy landscape plays a significant role in the difference between snap-through and snap-back characteristics, suppression of cross-well vibrations, and the tailoring of energy harvesting capabilities. This paper aims to systematically investigate the asymmetric nature of an MFC-bonded active square bistable laminate, where MFCs are used for shape morphing and energy harvesting actions. A Rayleigh–Ritz-based semi-analytical model and a fully nonlinear finite element (FE) framework have been used to predict the bistable behavior of MFC-bonded active bistable laminates. The FE model has been further utilized for parametric studies to examine the influence of the geometrical parameters of MFC layers in altering the energy landscape. Additionally, the influence of replacing conventional cross-ply laminates with variable stiffness (VS) laminates, generated from curvilinear fiber alignments, on the potential energy landscape has been examined on the best-identified laminate-MFC configuration from the initial FE parametric study. As an outcome, an optimum VS laminate-MFC configuration has been proposed for future investigations.
双稳态复合层压板的不对称特性涉及调整势能景观以实现可调行为,这对于优化其在各种变形和能量收集应用中的性能至关重要。传统的方形交叉层压板具有等电位最小值的完美对称特性。智能材料的加入,如用于变形和能量收集应用的压电宏纤维复合材料(MFC)致动器,导致双稳态MFC结构的总势能景观具有不对称性质。这种不对称的能量格局在快速通过和快速返回特性之间的差异、井间振动的抑制以及能量收集能力的定制方面发挥了重要作用。本文旨在系统地研究mfc键合的有源方形双稳态层叠板的不对称性质,其中mfc用于形状变形和能量收集动作。采用基于rayleigh - ritz的半解析模型和全非线性有限元框架对mfc键合活性双稳层合板的双稳行为进行了预测。进一步利用有限元模型进行参数化研究,考察了MFC层的几何参数对能量格局的影响。此外,用曲线纤维排列产生的变刚度(VS)层压板取代传统的交叉层合板对势能景观的影响已经在最初的有限元参数研究中最好识别的层压板- mfc配置上进行了检查。因此,一个最佳的VS层压板- mfc配置已提出,为未来的研究。
Effect of delamination defects on buckling and growth characteristics in composite laminates
S.S. Venkat, S. Scheffler, P.M. Anilkumar, E. Baranger, R. Rolfes
doi:10.1016/j.compstruct.2025.119245
分层缺陷对复合材料层合板屈曲和生长特性的影响
Delaminations pose a critical threat to the safety and reliability of composite structures due to increased risk of buckling and further growth under compressive loads. Understanding the interplay between how even seemingly minor interface defects can amplify the risk of buckling and how buckling in turn can affect the growth characteristics of existing delaminations is therefore crucial during the design phase of the structure. In this study, we focus on the column buckling case to get an understanding of growth characteristics of pre-existing delamination under compression. A quasi-static “Effect of Defect” study has been conducted using geometrically nonlinear finite element (FE) simulations. The study has been performed by maintaining a constant applied load while incrementally increasing the delamination length in the models. Different through thickness delamination configurations were investigated in a generic quasi-isotropic laminate and the configuration with delamination near the laminate surface was found to be most critical. It was observed that as the delamination length is increased, the laminate initially experiences local buckling. This is followed by unstable growth and a mixed local/global buckling failure when the delamination length reaches a critical size. For this near-surface configuration, the influence of laminate dimensions has been investigated and a comparison has been made between the original quasi-isotropic laminate and a stiffer, zero-dominant laminate. It has been demonstrated that in the stiffer laminate, under the same applied load, local buckling occurs without leading to unstable growth, even for very large delamination sizes. Therefore, in this case, if growth occurs under a service load equalling the applied load, it is expected to remain stable without transitioning to unstable growth. By understanding these distinct growth characteristics within the context of delamination buckling, designers can more effectively develop inspection strategies that improve the monitoring of damage growth.
分层对复合材料结构的安全性和可靠性构成了严重的威胁,因为它在压缩载荷下增加了屈曲和进一步生长的风险。因此,在结构的设计阶段,了解看似很小的界面缺陷如何放大屈曲风险以及屈曲如何反过来影响现有分层的生长特性之间的相互作用至关重要。在本研究中,我们重点研究了柱的屈曲情况,以了解压缩条件下已有分层的生长特征。采用几何非线性有限元(FE)模拟进行了准静态“缺陷效应”研究。该研究是通过保持恒定的施加载荷同时逐渐增加模型中的分层长度来进行的。研究了一类准各向同性层压板不同厚度的分层构型,发现靠近层压板表面的分层构型是最关键的。结果表明,随着分层长度的增加,层合板最初会发生局部屈曲。当分层长度达到临界尺寸时,随之而来的是不稳定的生长和局部/整体混合屈曲破坏。对于这种近表面结构,研究了层压板尺寸的影响,并将原始的准各向同性层压板与更硬的零优势层压板进行了比较。研究表明,在较硬的层压板中,在相同的载荷作用下,即使分层尺寸很大,也会发生局部屈曲而不会导致不稳定的生长。因此,在这种情况下,如果增长发生在服务负载等于应用负载的情况下,则预计它将保持稳定,而不会过渡到不稳定的增长。通过了解分层屈曲中这些不同的生长特征,设计人员可以更有效地制定检测策略,改善对损伤生长的监测。
Innovative 2D material enhanced 3D-printed sandwich lattice sheet-embedded composites: Advancements in transient energy absorption characteristics
J.Jefferson Andrew, MY. Khalid, WJ. Cantwell, KA. Khan, P. Potluri, R. Umer
doi:10.1016/j.compositesa.2025.109057
创新的2D材料增强了3d打印三明治晶格片嵌入复合材料:瞬态能量吸收特性的进步
This research investigates a novel 3D-printed sandwich lattice sheet-embedded composite laminate designed for enhanced impact resistance. Additive manufacturing parameters have been established for two corrugated, nanoengineered sandwich lattice sheet geometries: triangular and curved topologies—in addition to reference bulk structures. Nanocomposite sandwich lattice sheets with varying Graphene Nano Platelet (GNP) concentrations (0–0.5 wt%) have been manufactured and integrated into glass fiber-reinforced laminates using co-infusion and co-curing techniques. This innovative approach enables seamless integration of 3D-printed, nanoengineered lattice sheets, preserving in-plane properties while localizing GNP reinforcement for enhanced energy absorption and offering a scalable, industrially compatible toughening strategy. The investigation involved analyzing the molecular composition, microstructure, and bulk properties of the constituent materials used in the lattice sheet fabrication, before subjecting the lattice sheet-integrated laminates to drop-weight impact loading. The laminates exhibited an excellent improvement in impact resistance, showing up to a ∼ 170 % increase in initial collapse load compared to baseline samples. These sandwich lattice structures effectively reduced damage propagation and displayed superior energy absorbing characteristics, notably in the case of the triangular sandwich lattice-embedded laminates. The study highlights the potential of triangular sandwich lattice sheet-embedded laminates, specifically those with optimized GNP concentrations, for applications requiring an enhanced impact resistance.
本研究研究了一种新型的3d打印夹层晶格嵌入复合材料层压板,旨在增强抗冲击性。除了参考体结构外,还建立了两种波纹纳米工程夹心晶格板几何形状的增材制造参数:三角形拓扑和弯曲拓扑。纳米复合材料夹心晶格片具有不同的石墨烯纳米血小板(GNP)浓度(0-0.5 wt%),并通过共灌注和共固化技术集成到玻璃纤维增强层压板中。这种创新的方法可以实现3d打印、纳米工程晶格片的无缝集成,在保留平面内特性的同时,局部化GNP增强以增强能量吸收,并提供可扩展的、工业兼容的增韧策略。在对晶格板集成层压板进行落锤冲击载荷之前,研究包括分析晶格板制造中使用的组成材料的分子组成、微观结构和体积特性。层压板在抗冲击性方面表现出优异的改善,与基线样品相比,初始崩溃载荷增加了 ~ 170 %。这些夹层晶格结构有效地减少了损伤传播,并表现出优越的吸能特性,特别是在三角形夹层晶格嵌入层合板的情况下。该研究强调了三角形夹层晶格嵌板层压板的潜力,特别是那些具有优化GNP浓度的层压板,用于需要增强抗冲击性的应用。
High mechanical interlocking and hydrogen bonding based carboxymethyl cellulose/SiO2 composite structures for interfacial bonding of reinforced polyimide fiber/EPDM composites
Youquan Ling, Junjie Liu, Bolin Xiao, Hui Jin, Luxiang Zhao, Yanjiang Bai, Xi Zhang, Mei Liang, Yang Chen, Huawei Zou
doi:10.1016/j.compositesb.2025.112652
用于增强聚酰亚胺纤维/三元乙丙橡胶复合材料界面粘合的高机械联锁和氢键基羧甲基纤维素/二氧化硅复合结构
In this study, carboxymethyl cellulose (CMC), a polymer abundant in hydroxyl and carboxyl groups, was employed as an interfacial layer between polyimide fibers and EPDM rubber. The formation of hydrogen bonds between CMC and the polyimide fibers facilitated a robust encapsulation of CMC on the fiber surface. Additionally, a greater number of SiO2 nanoparticles were adsorbed onto the CMC surface through hydrogen bonding and condensation reactions, significantly enhancing the fiber's surface roughness and the matrix's wettability. This strong mechanical interlocking structure markedly improved the interfacial adhesion and mechanical properties of the composites. Specifically, the H pull-out force, tensile strength, and elongation at break increased by 84.8%, 89%, and 45%, respectively, compared to the control samples. In-situ electron microscopy further confirmed that the reinforced interface effectively inhibited crack propagation along the interface. Low-field NMR analysis revealed that the enhanced interfacial bonding restricted the mobility of rubber molecules, contributing to higher strains and stresses during the orientation hardening phase under tension. Moreover, the improved interfacial adhesion and the incorporation of SiO2 within the interfacial layer also enhanced the ablative resistance and thermal insulation properties. These findings demonstrate that the CMC/SiO2 encapsulation strategy represents an environmentally friendly, rapid, and efficient interfacial modification method for polyimide fiber-reinforced EPDM insulation materials.
在本研究中,羧甲基纤维素(CMC)是一种富含羟基和羧基的聚合物,作为聚酰亚胺纤维和三元乙丙橡胶之间的界面层。CMC与聚酰亚胺纤维之间氢键的形成促进了CMC在纤维表面的牢固封装。此外,通过氢键和缩合反应,更多的SiO2纳米颗粒被吸附在CMC表面,显著提高了纤维的表面粗糙度和基体的润湿性。这种强机械联锁结构显著提高了复合材料的界面附着力和力学性能。具体而言,与对照样品相比,H拔出力、抗拉强度和断裂伸长率分别提高了84.8%、89%和45%。原位电镜进一步证实,增强界面有效抑制了裂纹沿界面扩展。低场核磁共振分析表明,界面结合的增强限制了橡胶分子的迁移,导致取向硬化阶段在张力作用下产生更高的应变和应力。此外,界面附着力的改善和界面层内SiO2的掺入也提高了材料的耐烧蚀性和保温性能。这些研究结果表明,CMC/SiO2封装策略代表了一种环保、快速、高效的聚酰亚胺纤维增强EPDM绝缘材料界面改性方法。
Deep learning-based analysis of damage mechanisms in 3D angle-interlock woven composites under variable impact conditions
Huajun Ding, Wenjing Cao, Bohong Gu, Ruiyun Zhang, Baozhong Sun
doi:10.1016/j.compscitech.2025.111224
基于深度学习的三维角互锁编织复合材料变冲击损伤机理分析
This study presents an innovative method to improve deep learning segmentation of warp and weft yarns in composites, overcoming the shortcomings of existing deep learning techniques in accurately defining yarns. The method entails threshold screening of yarn area and aspect ratio, combined with morphological opening operations and an improved watershed algorithm to enhance the segmentation map’s accuracy. The findings indicate significant improvements in both continuity and accuracy. An examination of failure modes across various impact energy levels indicates that weft yarns mainly absorb energy and support loads; however, weak interfacial adhesion between yarns and resin leads to debonding, which is the main failure mode. At increased impact energies, cracks develop within the composite components rather than at interfaces. This implies that improving the interfacial bond between yarns and resin could strengthen impact resistance. Based on these observations, the study suggests utilizing resin with superior bonding characteristics to enhance the material’s impact resistance and longevity.
本研究提出了一种创新的方法来改进复合材料中经纱和纬纱的深度学习分割,克服了现有深度学习技术在准确定义纱线方面的不足。该方法对纱线面积和纵横比进行阈值筛选,结合形态学开放操作和改进的分水岭算法提高分割图的精度。研究结果表明,连续性和准确性都有显著提高。对不同冲击能级的破坏模式进行了分析,结果表明纬纱主要吸收能量和支撑载荷;然而,纱线与树脂之间的界面附着力较弱,导致脱粘,这是主要的失效方式。当冲击能量增加时,裂纹在复合材料部件内部而不是在界面处发展。这表明,改善纱线与树脂之间的界面结合可以增强抗冲击性。基于这些观察结果,该研究建议使用具有优越粘合特性的树脂来提高材料的抗冲击性和使用寿命。