今日更新:Composite Structures 4 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 1 篇
Multilayer heterostructure inhomogeneous model for the functionally graded spherical shell with rotation effect for arbitrarily varying material properties
Jun Xie, Hui Li, Fengjun Li, Pengpeng Shi
doi:10.1016/j.compstruct.2024.118145
具有任意变化材料性质的旋转效应的功能梯度球壳多层异质结构非均匀模型
With the development of functionally graded materials (FGMs) composite technology, structural safety analysis related to FGMs has been widely concerned. An innovative multilayer heterostructure power-law inhomogeneous (MHPI) model is taken to solve the rotating FGMs hollow spherical shell with arbitrarily varying material properties (elastic modulus and density) along the radial direction. The basic idea of MHPI is that the rotating FGMs spherical shell is divided into multiple sublayers, and power functions approximate the elastic modulus and density of each sublayer. For each single sublayer, the analytical solution includes two undetermined constants, which can be obtained from the boundary and continuity conditions. Many numerical examples of the rotating FGMs spherical shell are discussed, involving seven property profiles gradient laws assumptions, three boundary conditions, and nine volume fraction gradient models. Finally, this study further discusses the rotating FGMs spherical shell optimization design. The greatest advantage of this study is that the elastic response of the rotating FGMs spherical shell under various gradient assumptions is completely discussed. The numerical results show that the method can solve the problem of circumferential stress oscillation well and has good convergence and high accuracy. For many numerical examples, the error of the MHPI model results is about 5‰ when sublayer number reaches 15 .
随着功能梯度材料复合技术的发展,与功能梯度材料相关的结构安全分析受到了广泛关注。采用一种新颖的多层异质结构幂律非均匀(MHPI)模型,求解了材料性能(弹性模量和密度)沿径向任意变化的旋转fgm空心球壳。MHPI的基本思想是将旋转的fgm球壳分成多个子层,幂函数近似每个子层的弹性模量和密度。对于每一单一子层,解析解包含两个待定常数,可由边界条件和连续性条件获得。讨论了旋转fgm球壳的许多数值算例,涉及7种性质分布、梯度律假设、3种边界条件和9种体积分数梯度模型。最后,本研究进一步讨论了旋转fgm球壳的优化设计。本研究最大的优点是完整地讨论了旋转fgm球壳在各种梯度假设下的弹性响应。数值计算结果表明,该方法能较好地解决环向应力振荡问题,具有较好的收敛性和较高的精度。对于许多数值算例,当子层数达到15时,MHPI模型结果的误差约为5‰。
On torsion of FG elastic nanobeams on nonlocal foundations
Raffaele Barretta, Raimondo Luciano, Francesco Marotti de Sciarra, Marzia Sara Vaccaro
doi:10.1016/j.compstruct.2024.118146
FG弹性纳米梁在非局部地基上的扭转研究
A plethora of challenging nanomechanical applications deals with ultrasmall composite structures interacting with nonlocal media. To capture size dependent behaviours, effective tools of Nonlocal Continuum Mechanics can be conveniently adopted, provided that the relevant structural problem is well-posed. A crucial improvement in modeling of nanobeams on nanofoundations is provided in the present work with respect to the formulation based on the Eringen–Wieghardt nonlocal approach. Scale effects on FG nanobeams under torsion are effectively captured by exploiting the consistent stress-driven integral theory of elasticity. A novel formulation of size dependent elastic foundations is here introduced. Notably, the constitutive behaviour describing interaction between twisted nanobeams and surrounding media is modeled by spatial convolution driven by the torsional rotation field. It is shown that the governing structural problem is mathematically represented by an integro-differential formulation. An equivalent simpler differential problem is then proven to reduce computational burdens. Exemplar case-studies are finally examined to show efficacy of the developed nonlocal methodology.
大量具有挑战性的纳米力学应用涉及与非局部介质相互作用的超小复合结构。为了捕获尺寸依赖行为,可以方便地采用非局部连续介质力学的有效工具,只要相关结构问题是适定的。对于基于Eringen-Wieghardt非局部方法的纳米梁在纳米基础上的建模,本文提供了一个关键的改进。利用一致应力驱动的弹性积分理论,有效地捕获了FG纳米梁在扭转作用下的尺度效应。本文介绍了一种新的尺寸相关弹性基础公式。值得注意的是,描述扭曲纳米梁与周围介质相互作用的本构行为是由扭转旋转场驱动的空间卷积模拟的。结果表明,控制结构问题在数学上可以用积分-微分公式表示。然后证明了一个等效的更简单的微分问题可以减少计算负担。范例案例研究最后进行了检验,以显示所开发的非局部方法的有效性。
Equivalent single-layer model for hierarchical diamond honeycomb sandwich panels using variational asymptotic method
Miao Siqi, Zhong Yifeng, Zhou Yujie, Liu Rong, Irakoze Alain Evrard
doi:10.1016/j.compstruct.2024.118149
用变分渐近方法建立分层金刚石蜂窝夹层板的等效单层模型
Sandwich panels with a hierarchical core facilitate the optimal utilization of limited materials to enhance bearing capacity in strategic locations. Nevertheless, the complex sub-structural cells have hindered extensive investigation into their static and modal characteristics. The objective of this study is to obtain the effective plate properties by homogenizing the representative unit cell and subsequently applying them to a two-dimensional equivalent single layer model (2D-ESL) based on the variational asymptotic method (VAM). Furthermore, three-point bending test of 3D-printed specimen and 3D detailed finite element results are employed to confirm the predictions of 2D-ESL under various load and boundary conditions. The effects of material factors (such as fiber volume fraction and layup configuration) and structural parameters (including aspect ratio, hierarchy ratio, and slenderness ratios of ribs and ligaments) on the equivalent stiffness and modal characteristics are also examined. Moreover, sandwich panels with different hierarchical configurations (including 2, 3 and infinite segments within the inclined ribs) are investigated to provide valuable insights for selecting appropriate hierarchies based on specific conditions. Notably, the transition from polyline to arc-shaped segments has been proven to effectively mitigate local stress concentration, leading to a more uniform distribution of local displacement.
具有分层核心的夹层板有利于有限材料的最佳利用,以提高战略位置的承载能力。然而,复杂的子结构单元阻碍了对其静力和模态特性的广泛研究。本研究的目的是通过均匀化代表性单元细胞,然后将其应用于基于变分渐近方法(VAM)的二维等效单层模型(2D-ESL),从而获得有效的板性能。通过三维打印试件三点弯曲试验和三维细部有限元结果验证了2D-ESL在不同载荷和边界条件下的预测结果。材料因素(如纤维体积分数和铺层结构)和结构参数(包括长径比、层次比和肋和韧带的长细比)对等效刚度和模态特性的影响也进行了研究。此外,研究了具有不同层次结构的夹层板(包括斜肋内的2段、3段和无限段),为根据特定条件选择合适的层次结构提供了有价值的见解。值得注意的是,从多线段到弧形段的过渡已被证明可以有效地缓解局部应力集中,从而使局部位移分布更加均匀。
Planar delamination behaviour of CFRP panels under quasi-static out-of-plane loading
Wenjie Tu, John-Alan Pascoe, René Alderliesten
doi:10.1016/j.compstruct.2024.118137
准静态面外荷载作用下CFRP板的平面分层行为
In this study, a novel experimental approach was devised to investigate shear dominant and combined opening-shear planar delamination behaviours in composite laminates subjected to quasi-static out-of-plane loading. The patterns of planar delamination growth were depicted through different inspection techniques, including digital image correlation (DIC), C-scan, and microscopic observation. The artificially embedded delamination propagated in the direction parallel to the fibre orientation of the layer above the mid interface, but migrated to an upper interface in the direction transverse to the directing ply. A continuous stiffening process was recognized with increasing delamination area. Furthermore, a numerical analysis based on virtual crack closure technique (VCCT) indicated that the local mode II was dominant for delamination growth, while the local mode III triggered delamination migration.
在本研究中,设计了一种新的实验方法来研究复合材料层合板在准静态面外加载下的剪切主导和开剪联合平面分层行为。通过不同的检测技术,包括数字图像相关(DIC)、c扫描和显微观察,描绘了平面分层生长的模式。人工嵌入的脱层沿平行于中间界面上方层的纤维取向方向传播,但沿与定向层横向的方向迁移到上部界面。随着分层面积的增加,可以识别出连续的硬化过程。此外,基于虚拟裂纹闭合技术(VCCT)的数值分析表明,局部模式II对分层扩展起主导作用,而局部模式III则引发分层迁移。
Complex hydrogel for cartilage regeneration and anti-inflammation
Xiao Jiang, Dapeng Li, Jade Tassey, Jiayi Li, Jialin Liu, Guojian Li, Yuzhi Sun, Xiao Zhao, Tianming Wang, Yongqiang Zhang, Yufeng Wang, Chenyu Huang, Yan Xu, Liming Wang, Nancy Q.Liu, Denis Evseenko, Qingqiang Yao
doi:10.1016/j.compositesb.2024.111481
用于软骨再生和抗炎的复合水凝胶
With the increasing incidence of osteoarthritis (OA) in elderly patients and the challenges posed by its multifaceted pathogenesis in developing effective treatments, this study explores the effective protein loading mode of Progranulin (PGRN) and its therapeutic potential for treating OA. GelMA hydrogels prepared with different concentrations of PGRN, employing AC-PEG-NHS as a crosslinking agent for drug encapsulation, were used to test the sustained release effect of the composite hydrogel drug delivery system. Additionally, we conducted in vitro assays to investigate the regulatory effects on rat bone marrow mesenchymal atromal cells (BMSCs), chondrocytes, and mouse macrophages - focusing on cell proliferation, and differentiation. For in vivo studies, histological staining techniques were utilized to assess inflammatory cell polarization and cartilage repair in a rat knee injury model. The results demonstrated that PGRN-loaded hydrogels significantly accelerated cell proliferation, enhance differentiation of BMSCs into chondrocytes, maintained a healthy chondrocyte phenotype, and induce M2-type polarization while inhibiting M1-type polarization in macrophages. Histological analyses also showed markedly improved tissue repair in the group treated with GelMA-NHS-PGRN hydrogels. As a result, these GelMA-NHS-PGRN hydrogels present a promising therapeutic approach for OA, potentially mitigating chronic inflammation and facilitating cartilage repair through controlled release of PGRN.
随着老年患者骨关节炎(OA)发病率的增加,以及其多发病机制给开发有效治疗方法带来的挑战,本研究探讨了前蛋白蛋白(proanulin, PGRN)的有效蛋白负载模式及其治疗OA的潜力。以不同浓度的PGRN制备GelMA水凝胶,以AC-PEG-NHS为交联剂进行药物包封,测试复合水凝胶给药体系的缓释效果。此外,我们还进行了体外实验,研究其对大鼠骨髓间充质间质细胞(BMSCs)、软骨细胞和小鼠巨噬细胞的调节作用,重点关注细胞增殖和分化。在体内研究中,利用组织学染色技术评估大鼠膝关节损伤模型中的炎症细胞极化和软骨修复。结果表明,载pgrn水凝胶可显著加速细胞增殖,增强骨髓间充质干细胞向软骨细胞的分化,维持健康的软骨细胞表型,诱导巨噬细胞m2型极化,抑制m1型极化。组织学分析也显示GelMA-NHS-PGRN水凝胶组的组织修复明显改善。因此,这些GelMA-NHS-PGRN水凝胶为OA提供了一种有希望的治疗方法,可能减轻慢性炎症,并通过控制PGRN的释放促进软骨修复。
Biomimetic versatile wood hybrids with gradient structure towards lightweight, high strength, fire-retardant, and deterioration-resistant materials
Qi Fan, Xing Zhang, Chuanfu Chen, Xiaolong Hao, Zhenzhen Liu, Rongxian Ou, Qingwen Wang
doi:10.1016/j.compositesb.2024.111483
具有梯度结构的仿生多功能木材混合材料,趋向于轻质、高强、阻燃和耐变质材料
The development of versatile wood-based biomaterials with integrated low density, high surface hardness, high strength, fire-resistance, anti-decay, and termite-resistance is highly desirable, yet challenging to skillfully fabricate. Inspired by the ubiquity of gradient biostructures in nature, we achieve biomimetic gradient densification structures by controlling the distribution of thermal-moisture fields within the wood, and combine this with in-situ curing of polyacrylic acid/borate supramolecular resins within the wood cells to transform bulk natural wood into lightweight, high strength, and multifunctional materials. The optimally gradient-densified hybrid wood, with a slight increase in density, demonstrates markedly improved mechanical properties (≈2.4× increase in surface hardness, ≈52% increase in flexural strength), excellent dimensional stability, and leaching resistance. In addition, the collaboration of the gradient-densified structure and the in-situ cured acrylic resin/borate supramolecular network provides the biomimetic wood hybrids with excellent fire resistance (V-0 rating in fire retardant grade, 74% reduction in total smoke release, ≈2.5× increase in fire performance index), decay and mildew resistance (mass loss of less than 10%), as well as termite resistance (100% protection efficiency and termite kill rate) properties. It is the first report to combine gradient densification with in-situ curing of supramolecular resins in the structural design and functionalization of wood-based composites. This new design principle provides guidance for fabricating advanced all-in-one wood materials with applications in lightweight, strong, fire-resistant, deterioration-resistant, and scalable building and furniture materials.
开发集低密度、高表面硬度、高强度、耐火、防腐、抗白蚁为一体的多功能木基生物材料是迫切需要的,但在技术制造方面具有挑战性。受自然界中普遍存在的梯度生物结构的启发,我们通过控制木材内部热湿场的分布来实现仿生梯度致密化结构,并将其与木材细胞内聚丙烯酸/硼酸盐超分子树脂的原位固化相结合,将大块天然木材转化为轻质、高强度和多功能的材料。优化后的梯度密实杂交木材,在密度略有增加的情况下,力学性能明显改善(表面硬度提高≈2.4倍,抗折强度提高≈52%),尺寸稳定性好,抗浸出性好。此外,梯度致密结构与原地固化丙烯酸树脂/硼酸盐超分子网络的协同作用,使仿生杂木具有优异的防火性能(阻燃级V-0级,总烟释放量降低74%,防火性能指数提高约2.5倍),抗腐霉性能(质量损失小于10%),以及抗白蚁性能(100%防护效率和白蚁杀灭率)。本文首次将梯度致密化与超分子树脂原位固化相结合,用于木基复合材料的结构设计与功能化。这种新的设计原则为制造先进的一体化木材材料提供了指导,这些材料应用于轻质、坚固、耐火、耐变质和可伸缩的建筑和家具材料。
Biomimetic dually cross-linked injectable poly(L-glutamic acid) based nanofiber composite hydrogels with self-healing, osteogenic and angiogenic properties for bone regeneration
Bo Wang, Jia Liu, Chao Guo, Xiaogang Bao, Liangfa Qi, Jingbo Yin, Guohua Xu, Shifeng Yan
doi:10.1016/j.compositesb.2024.111492
仿生双交联可注射聚l -谷氨酸纳米纤维复合水凝胶,具有自愈、成骨和血管生成特性,用于骨再生
Biomimetic hydrogels with satisfactory mechanical properties and osteogenic/angiogenic abilities have attracted extensive attention in recent years. Injectable hydrogels with the advantages of minimally invasive implantation and adaptability to irregular defects exhibit superior application potential in the field of bone regeneration. However, poor mechanical properties and limited self-healing ability hinder their potential as supporting materials. Furthermore, the absence of osteogenic and angiogenic properties significantly affect their application in bone regeneration. For injectable hydrogels, simulating natural bone tissue ECM presents an opportunity for developing innovative materials for bone repair. In this work, a strategy to prepare biomimetic nanofiber-reinforced dually cross-linked (DC) injectable hydrogels with self-healing, osteogenic and angiogenic properties was proposed. The PLGA/MDex/CaP@PBLG nanofiber hydrogels were crosslinked through two reversible dynamic interactions including Schiff base reaction and physical chelation, thereby demonstrating good self-healing property. Meanwhile, the incorporation of CaP@PBLG mineralized nanofibers and alendronate sodium (BP) grafted on PLGA could endow the hydrogels with favorable osteogenic function. Moreover, the introduction of antioxidant ferulic acid (FA) could significantly stimulate angiogenic activity of the hydrogels. The successful regeneration of cranial defects in rats demonstrated a potential application of PLGA/MDex/CaP@PBLG nanofiber hydrogels in the field of bone regeneration.
仿生水凝胶具有良好的力学性能和成骨/血管生成能力,近年来引起了广泛的关注。可注射水凝胶具有微创植入和适应不规则缺损等优点,在骨再生领域具有较好的应用潜力。然而,较差的力学性能和有限的自愈能力阻碍了它们作为支撑材料的潜力。此外,缺乏成骨和血管生成特性显著影响其在骨再生中的应用。对于可注射的水凝胶,模拟天然骨组织ECM为开发用于骨修复的创新材料提供了机会。在这项工作中,提出了一种具有自愈、成骨和血管生成特性的仿生纳米纤维增强双交联(DC)可注射水凝胶的制备策略。PLGA/MDex/CaP@PBLG纳米纤维水凝胶通过希夫碱反应和物理螯合两种可逆动态相互作用交联,表现出良好的自愈性能。同时,CaP@PBLG矿化纳米纤维的掺入和阿仑膦酸钠(BP)在PLGA上的移植可以使水凝胶具有良好的成骨功能。此外,抗氧化剂阿魏酸(FA)的引入可以显著促进水凝胶的血管生成活性。大鼠颅骨缺损的成功再生证明了PLGA/MDex/CaP@PBLG纳米纤维水凝胶在骨再生领域的潜在应用。
Exosomes Endow Photocurable 3D Printing 45S5 Ceramic Scaffolds to Enhance Angiogenesis-osteogenesis Coupling for Accelerated Bone Regeneration
Weiqing Kong, Ya Ren, Changru Zhang, Ya’nan Wang, Jianyi Li, Yukun Du, Xuelian Mi, Xiaokun Yue, Hong Zeng, Yihao Liu, Haoyi Niu, Jinwu Wang, Yongming Xi
doi:10.1016/j.compositesb.2024.111455
外泌体赋予光固化3D打印45S5陶瓷支架增强血管生成-成骨耦合加速骨再生
The reconstruction of the vascular network is crucial step in bone regeneration. Therefore, effectively modulating angiogenesis-osteogenesis coupling in bone tissue engineering scaffolds is currently an urgent need. In this study, we employed silane coupling agents containing double bonds to modify tetrahedral silicate, resulting in the preparation of a photocurable precursor of 45S5 bioactive glass (PG). PG was utilized as a binding agent for tricalcium phosphate (TCP) powder, and we employed a one-step photocuring 3D printing approach to fabricate PG/TCP (PT) scaffolds. Furthermore, the endothelial progenitor cell-derived exosomes (EPC-exos) was encapsulated by GelMA and anchored onto the PT scaffolds to create exosome-functionalized PT/G@Exos composite scaffolds. In summary, the PT/G@Exos composite scaffold effectively orchestrates the creation of a vascularized bone regeneration microenvironment by releasing EPC-exos, as well as calcium, silicon (Si), and phosphorus (P) elements. This enables an efficient modulation of the angiogenesis-osteogenesis coupling of bioactive scaffolds and accelerates bone regeneration.
血管网的重建是骨再生的关键步骤。因此,有效调节骨组织工程支架中血管生成-成骨耦合是目前迫切需要的。在本研究中,我们采用含有双键的硅烷偶联剂对四面体硅酸盐进行修饰,制备了可光固化的45S5生物活性玻璃(PG)前驱体。以PG作为磷酸三钙(TCP)粉末的结合剂,采用一步光固化3D打印的方法制备PG/TCP (PT)支架。此外,内皮祖细胞来源的外泌体(EPC-exos)被GelMA包封并固定在PT支架上,形成外泌体功能化的PT/G@Exos复合支架。总之,PT/G@Exos复合支架通过释放EPC-exos以及钙、硅(Si)和磷(P)元素,有效地协调了血管化骨再生微环境的创建。这使得生物活性支架的血管生成-成骨耦合的有效调节和加速骨再生。
Self-diagnosis of structural damage in self-powered piezoelectric composites
Binbin Zhao, Zefei Cheng, Yanfang Zhu, Lulu Lei, Zhibiao Wei, Chao Ji, Tao Yu, Jinhong Fan, Weidong Yang, Yan Li
doi:10.1016/j.compscitech.2024.110619
自供电压电复合材料结构损伤的自诊断
At present, nondestructive testing and non-self-powered structure health monitoring methods are usually used to judge the damage of fiber reinforced composites. However, these methods have some limitations due to the lack of real-time characteristics, the need for external power supply or the complex structure of sensor. In this work, the piezoelectric nanogenerator mechanism was integrated into the traditional composites to develop the piezoelectric composite with damage self-diagnosis function. The piezoelectric composites can realize structural health monitoring and damage localization without reducing the original mechanical properties. The effects of PVDF and barium titanate on the mechanical properties of the composites were investigated by experiments and simulations. Furthermore, the damage self-diagnosis characteristics of composites under bending load and impact load were studied. The algebraic relationship between the damage area and the open circuit voltage under impact load was established. In addition, the damage localization of composite materials is realized by designing an Application (APP). In general, this work has successfully set a precedent for the application of nanogenerator mechanism to the self-powered and self-diagnosis of composite damage, which has the potential to be used in any field related to composites, such as aerospace, etc.
目前,通常采用无损检测和非自供电结构健康监测方法来判断纤维增强复合材料的损伤。然而,由于缺乏实时性、需要外部电源或传感器结构复杂等原因,这些方法存在一定的局限性。本研究将压电纳米发电机机制整合到传统复合材料中,开发具有损伤自诊断功能的压电复合材料。压电复合材料可以在不降低其原有力学性能的前提下实现结构健康监测和损伤定位。通过实验和模拟研究了PVDF和钛酸钡对复合材料力学性能的影响。进一步研究了复合材料在弯曲载荷和冲击载荷作用下的损伤自诊断特性。建立了冲击载荷作用下损伤面积与开路电压之间的代数关系。此外,通过设计应用程序(APP)实现复合材料损伤的局部化。总的来说,这项工作成功地开创了将纳米发电机机制应用于复合材料损伤自供电和自诊断的先例,具有应用于任何与复合材料相关的领域的潜力,如航空航天等。