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【新文速递】2024年12月29日复合材料SCI期刊最新文章

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今日更新:Composite Structures 4 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇

Composite Structures

Uniform winding path generation for Non-Axisymmetric mandrels

Shuo Li, Zhuo Meng, Yujing Zhang, Yize Sun

doi:10.1016/j.compstruct.2024.118834

非轴对称心轴均匀缠绕路径生成

Creating a continuous and uniform winding path may be a challenging task due to the complex surface characteristics, resulting in limitations in designing winding paths for non-axisymmetric mandrel. A design method is proposed to generate uniform winding path for non-axisymmetric mandrel by transforming the mandrel surface into discrete triangle meshes. This method involves generating winding paths in three parts: the basic path, the replication paths, and the transitional paths. Firstly, the variable winding angle of basic path is obtained according to the mandrel cross-sectional characteristics to generate the basic path with uniform fiber coverage; Secondly, the cross-sectional equidistant points are calculated according to the position of basic path on the mandrel cross-section, and the replication paths through the equidistant points are generated based on dichotomy principle to obtain uniform fiber distribution in the circumferential direction of mandrel; Thirdly, according to the required winding pattern, each transitional path is generated to connect its two corresponding replication paths. Finally, the continuous winding path is formed by the basic path, replication paths, and transitional paths. The method is applied to different non-axisymmetric mandrels, and the results show that this method can flexibly generate uniform winding paths with desired winding angle and winding pattern.

由于复杂的表面特性,创建连续均匀的缠绕路径可能是一项具有挑战性的任务,从而限制了非轴对称芯轴缠绕路径的设计。提出了一种将心轴表面转化为离散三角形网格的非轴对称心轴均匀缠绕路径设计方法。该方法包括生成三部分绕组路径:基本路径、复 制路径和过渡路径。首先,根据芯棒截面特性获得可变缠绕角的基本路径,生成纤维覆盖均匀的基本路径;其次,根据基本路径在芯棒截面上的位置计算截面等距点,并基于二分法原理生成通过等距点的复 制路径,获得芯棒圆周方向均匀的纤维分布;第三,根据需要的缠绕模式,生成每条过渡路径,连接其对应的两条复 制路径。最后由基本路径、复 制路径和过渡路径组成连续缠绕路径。将该方法应用于不同的非轴对称芯轴,结果表明,该方法可以灵活地生成具有理想缠绕角和缠绕方式的均匀缠绕路径。


A localised continuum damage mechanics model for fibre failure in explicit integration

Jagan Selvaraj, Timothee Chastel, Stephen R. Hallett

doi:10.1016/j.compstruct.2024.118816

显式积分中纤维破坏的局部连续损伤力学模型

In finite element analyses, Continuum Damage Mechanics (CDM) typically models failure by smearing the damage over the volume of each element. Although this works well when the mesh sizes are small and closer to size of the cracks, numerical accuracy of CDM at larger mesh sizes and length-scales is limited. For instance, fibre failure in laminated composite materials is accompanied by a large amount of energy release over a small volume and the numerical accuracy in modelling this localised phenomenon is tied to the spatial resolution of the mesh. To overcome this inherent mesh dependency in damage propagation, a localisation band is introduced within the continuum elements such that elastic and damage regions can be separated using kinematic enhancement, without modelling geometric discontinuities. This separation enables cracks to be modelled as localised features and thus the stress concentrations and damage propagation are modelled more accurately than conventional CDM. This framework is here combined with a higher-order continuum element such that improved predictions can be obtained for the damage initiation stress compared to linear elements. This combined method is demonstrated using Over-height Compact Tension (OCT) and Open-Hole Tensile (OHT) tests where the dominant mechanism is fibre failure. The results are compared against experiments as well as ply-level discrete crack models.

在有限元分析中,连续损伤力学(CDM)通常通过涂抹每个单元的体积损伤来模拟失效。虽然这种方法在网格尺寸较小且接近裂纹尺寸时效果良好,但在较大网格尺寸和长度尺度下,CDM的数值精度受到限制。例如,层压复合材料中的纤维破坏伴随着小体积上的大量能量释放,模拟这种局部现象的数值精度与网格的空间分辨率有关。为了克服损伤传播中固有的网格依赖性,在连续单元中引入了局部化带,这样可以使用运动学增强将弹性区域和损伤区域分开,而无需建模几何不连续。这种分离可以将裂缝建模为局部特征,从而比传统的CDM更准确地模拟应力集中和损伤传播。该框架与高阶连续单元相结合,与线性单元相比,可以得到更好的损伤起裂应力预测。这种组合方法通过超高度致密拉伸(OCT)和裸眼拉伸(OHT)测试进行了验证,其中主要机制是纤维破坏。计算结果与实验结果以及层级离散裂纹模型进行了比较。


Ultra broadband low-frequency vibration and pulse mitigation of electromagnetic induction-based metastructure

Yu Sun, Haokai Zheng, Qiang Han, Chunlei Li

doi:10.1016/j.compstruct.2024.118821

基于电磁感应的超宽带低频振动与脉冲抑制元结构

Elastic metastructures have attracted extensive research interest for their unique properties of generating bandgaps to mitigate vibration. However, it is difficult for conventional metastructures to obtain ultra-wide bandgap in low-frequency domain. To address this challenge, a novel bandgap active control mechanism is proposed and applied to locally resonant metastructures. The magnetic resonator perfectly combines the dual mechanism of negative stiffness and electromagnetic induction, which allows the start and end frequencies of bandgap to be tuned flexibly to obtain ultra-broadband and low-frequency wave mitigation domain. The theoretical bandgap is derived from extended plane wave expansion method and verified by numerical simulation and experiment. The results show that the bandwidth is broadened by about 3.5 times than before and the quasi-bandgap with extremely-low frequency is induced under the action of electromagnetic damping. By regulating the spacing, the quasi-bandgap and bandgap can be coupled to form strong wave mitigation domain covering the frequency below 300Hz. Besides, the proposed metastructures exhibit stronger pulse mitigation enhancement and resonance peak attenuation in low-frequency domain. This study is expected to provide a new design concept for the performance development of smart elastic/acoustic wave devices such as low-frequency vibration energy harvester, vibration isolator and metasurface, etc.

弹性元结构以其产生带隙以减轻振动的独特特性引起了广泛的研究兴趣。然而,传统的元结构很难在低频域获得超宽的带隙。为了解决这一挑战,提出了一种新的带隙主动控制机制,并将其应用于局部谐振元结构。该磁谐振器完美地结合了负刚度和电磁感应的双重机制,可以灵活地调整带隙的起始和结束频率,从而获得超宽带和低频的消波域。理论带隙由扩展平面波展开法推导,并通过数值模拟和实验验证。结果表明,在电磁阻尼的作用下,带宽比以前宽了约3.5倍,并产生了极低频的准带隙。通过调节带隙和准带隙的间距,可以形成覆盖300Hz以下频率的强消波域。此外,所提出的元结构在低频域表现出更强的脉冲减缓增强和共振峰值衰减。该研究有望为低频振动能量采集器、隔振器、超表面等智能弹性/声波器件的性能开发提供新的设计理念。


Auxetic behavior and energy absorption characteristics of a lattice structure inspired by deep-sea sponge

Jiaming Ma, Hongru Zhang, Ting-Uei Lee, Hongjia Lu, Yi Min Xie, Ngoc San Ha

doi:10.1016/j.compstruct.2024.118835

受深海海绵启发的晶格结构的补充行为和能量吸收特性

Auxetic metamaterials, characterized by their lateral contraction under compression, have seen notable progress in recent years, largely due to advancements in 3D printing technologies. However, their practical application remains constrained by limited design versatility, moderate improvements in negative Poisson’s ratio (NPR), and relatively low structural stiffness. To address these challenges, a bio-inspired lattice structure (BLS) has been developed, drawing inspiration from the skeletal system of deep-sea hexactinellid sponges, renowned for their exceptional energy absorption capabilities, stiffness, and mechanical properties. Although this structure exhibits auxetic behavior, a comprehensive understanding of its mechanical performance, including its auxetic properties, remains incomplete. In this study, we systematically explore the auxetic behavior, stiffness, and energy absorption properties of the BLS through a combination of quasi-static compression experiments and detailed numerical simulations using finite element analysis. The experimental results reveal that the BLS outperforms conventional auxetic structures, such as re-entrant hexagonal honeycombs, in terms of NPR, stiffness, and energy absorption capacity. Furthermore, a parametric study is conducted to evaluate the influence of geometric variations, such as member thickness and spacing, on the mechanical performance of the BLS. These findings demonstrate that the BLS has the potential to pioneer a new class of auxetic materials, offering superior mechanical properties and broad applicability in engineering fields that require enhanced energy absorption and structural stiffness under compressive loading.

近年来,由于3D打印技术的进步,以压缩下的侧向收缩为特征的增塑型超材料取得了显著进展。然而,它们的实际应用仍然受到有限的设计通用性、负泊松比(NPR)的适度改善和相对较低的结构刚度的限制。为了应对这些挑战,一种仿生晶格结构(BLS)已经被开发出来,其灵感来自深海海绵体的骨骼系统,以其卓越的能量吸收能力、刚度和机械性能而闻名。尽管这种结构表现出形变行为,但对其力学性能,包括其形变特性的全面了解仍然不完整。在本研究中,我们通过准静态压缩实验和详细的有限元数值模拟相结合,系统地探讨了BLS的消声行为、刚度和能量吸收特性。实验结果表明,该结构在NPR、刚度和能量吸收能力等方面均优于传统的六边形重入式蜂窝结构。此外,还进行了参数化研究,以评估构件厚度和间距等几何变化对BLS力学性能的影响。这些发现表明,BLS有潜力开拓一种新型的增减材料,提供卓越的机械性能和广泛的适用性,在压缩载荷下需要增强能量吸收和结构刚度的工程领域。


Composites Part A: Applied Science and Manufacturing

From properties to performance: Understanding the multifunctional performance of carbon fiber cathodes for structural batteries

Nur Ayu Afira Sutrisnoh, Gwendolyn J.H. Lim, Kwok Kiong Chan, Karthikayen Raju, J.J.Nicholas Lim, J.Justin Koh, Derrick W.H. Fam, Madhavi Srinivasan

doi:10.1016/j.compositesa.2024.108696

 

从性质到性能:了解结构电池用碳纤维阴极的多功能性能

Structural batteries are multifunctional rechargeable batteries that can simultaneously store electrochemical energy and carry mechanical load. The cathode component of structural batteries is usually fabricated by functionalizing lightweight carbon fibers with cathode materials and regarded as carbon fiber cathodes (CFC). With a myriad of fabrication techniques, cathode active materials and types of carbon fibers readily available, endless variation of CFC can be produced, each with differing electrochemical and mechanical properties. Here, a fundamental study to systematically relate materials’ properties to resultant multifunctional performance of CFC were probed. Intrinsic physicochemical and mechanical properties of carbon fibers were first investigated before factors affecting the multifunctional performance of CFC were determined. Through this, a high-performing CFC with specific capacity of 155 mAh g−1 and stiffness of 72 GPa was developed. Correlation studies between the multifunctional properties were also assessed to provide comprehensive understanding and serve as a guide for future fabrication of CFC.

结构电池是一种能同时储存电化学能量和承载机械负荷的多功能可充电电池。结构电池的正极部件通常是用轻质碳纤维功能化正极材料制成的,称为碳纤维阴极(CFC)。有了无数的制造技术、阴极活性材料和碳纤维类型,可以生产出无穷无尽的CFC变化,每一种都具有不同的电化学和机械性能。在这里,系统地将材料的性质与CFC的多功能性能联系起来的基础研究进行了探讨。首先研究了碳纤维的内在物理化学和力学性能,然后确定了影响CFC多功能性能的因素。开发出比容量为155 mAh g−1、刚度为72 GPa的高性能CFC。本文还对其多功能特性之间的相关研究进行了评估,为今后CFC的制备提供了全面的认识和指导。


Composites Part B: Engineering

Innovative MoS2/C Composite with High Elasticity and Ion Permeability for Next-Gen Sodium Anodes

Xingbo Yu, Shengqin Guan, Guoli Zhang, Huihui Li, Jianlong Wang, Zhichang Liu, Baoen Xu, Kaixi Li, Taotao Guan

doi:10.1016/j.compositesb.2024.112101

 

新一代钠阳极用高弹性和离子渗透率的MoS2/C复合材料

Carbon-coating technology is revolutionizing the large-scale application of transition metal sulfides (TMSs) in sodium-ion storage by mitigating structural expansion and enhancing conductivity. However, the weak interaction between the core-shell and the excessive rigidity of the carbon shell have limited the stability and application potential of these composites. To overcome these challenges, we employed a confined-space chemical vapor deposition method to prepare MoS2/C composites with a balanced mix of soft and hard carbon. This innovative carbon shell ensures both flexibility and permeability, facilitating the efficient hosting of sodium ions. Moreover, numerous C-S bonds between the carbon shell and TMS core further minimize irreversible deformation during repeated sodium ion insertion and extraction. The resulting Mo1C2H1S1-1000 composite demonstrates exceptional cycling stability and rate performance. After 100 cycles at 0.1 A g-1, its capacity increases by 20-fold compared to pure MoS2, and at 5 A g-1, it outperforms pure MoS2 by more than 200-fold. Density functional theory (DFT) calculations further validate the enhanced sodium storage capacity and conductivity conferred by the carbon coating. This comprehensive strategy also enhances the structural stability of other composites, such as FeS/C and NiS/C, paving the way for next-generation sodium-ion battery anodes.

碳涂层技术通过减轻结构膨胀和提高导电性,革新了过渡金属硫化物(tms)在钠离子存储中的大规模应用。然而,核壳之间的弱相互作用和碳壳的过度刚度限制了这些复合材料的稳定性和应用潜力。为了克服这些挑战,我们采用密闭空间化学气相沉积方法制备了软硬碳平衡混合的MoS2/C复合材料。这种创新的碳壳确保了灵活性和渗透性,促进了钠离子的有效承载。此外,碳壳和TMS核之间的大量C-S键进一步减少了反复插入和提取钠离子时的不可逆变形。得到的Mo1C2H1S1-1000复合材料具有优异的循环稳定性和速率性能。在0.1 A g-1下循环100次后,其容量比纯MoS2增加了20倍,在5 A g-1下,其性能比纯MoS2高出200倍以上。密度泛函理论(DFT)计算进一步验证了碳涂层增强的钠储存能力和电导率。这种综合策略还提高了其他复合材料的结构稳定性,如FeS/C和NiS/C,为下一代钠离子电池阳极铺平了道路。


Novel flexible polyether segment polybenzoxazine shape memory nanocomposites reinforced by incorporating functionalized carbon nanotubes

Wei Zhao, Ai Ping Zhang, Xin Kang Li, Jun Bian, Shang Ke Yang, Ke Yang Ni, Ke Cheng Yang, Hai Lan Lin, Dai Qiang Chen

doi:10.1016/j.compositesb.2024.112104

 

采用功能化碳纳米管增强柔性聚醚段聚苯并恶嗪形状记忆纳米复合材料

This work focused on designing and investigating a novel flexible polyether segment polybenzoxazine (PBZ) shape memory nanocomposites reinforced by incorporating amination modification multiwalled carbon nanotubes (MWCNTs-NH2) through in-situ solution polymerization. FTIR, XRD, Raman, SEM, TEM, XPS and TGA spectroscopy tests elucidated the chemical structure of functionalized MWCNTs and indicated the success preparation of functionalized MWCNTs. The preparation of PBZ and PBZ/MWCNTs-NH2 was validated by NMR, FTIR, and XPS. The introduction of MWCNTs-NH2 enhanced the compatibility between MWCNTs and the PBZ matrix, thereby contributing to the property improvements. The resultant PBZ nanocomposites showed the highest tensile strength of 46.9 MPa and a maximum elongation at break of 5.6 % respectively at 3 wt% filler content, and the maximum elastic modulus of 1400.1 MPa was obtained at the filler content of 1 wt%. DMA testing verified a noteworthy enhancement in both Tg and storage modulus upon incorporating of MWCNTs-NH2 due to improved interface bonding strength between PBZ matrix and MWCNTs-NH2. Through TGA analysis, it can be concluded that the introduction of MWCNTs-NH2 enhances thermal stability. Morphological analysis unveiled a compact and dense microstructure within the nanocomposites in correlation with functionalized MWCNTs and their concentration. The optimal shape memory performance with 93.54 % Rf, 87.09 % Rr, and 4.3°/s V were observed at a MWCNTs-NH2 content of 3 wt% (100 °C). In summary, this comprehensive investigation demonstrated the impact of functionalized MWCNTs on the mechanical, thermal, electrical, and shape memory properties of the PBZ shape memory nanocomposites.

本研究致力于通过原位溶液聚合设计并研究一种新型柔性聚醚段聚苯并噁嗪(PBZ)形状记忆纳米复合材料,该材料通过掺入胺化改性多壁碳纳米管(MWCNTs-NH2)进行增强。傅里叶变换红外光谱(FTIR)、X 射线衍射(XRD)、拉曼光谱、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X 射线光电子能谱(XPS)和热重分析(TGA)等测试阐明了功能化 MWCNTs 的化学结构,并表明成功制备了功能化 MWCNTs。核磁共振(NMR)、FTIR 和 XPS 证实了 PBZ 和 PBZ/MWCNTs-NH2 的制备。MWCNTs-NH2 的引入增强了 MWCNTs 与 PBZ 基体之间的相容性,从而有助于性能的提升。所得 PBZ 纳米复合材料在 3%(质量分数)的填料含量下分别表现出最高的拉伸强度 46.9 MPa 和最大断裂伸长率 5.6%,在 1%(质量分数)的填料含量下获得最大弹性模量 1400.1 MPa。动态热机械分析(DMA)测试证实,由于 PBZ 基体与 MWCNTs-NH2 之间界面结合强度的提高,在掺入 MWCNTs-NH2 后,玻璃化转变温度(Tg)和储能模量均显著提高。通过热重分析(TGA)可以得出结论,引入氨基化多壁碳纳米管(MWCNTs-NH2)增强了热稳定性。形态分析揭示了纳米复合材料内部具有致密的微观结构,这与功能化的多壁碳纳米管及其浓度相关。在 3 重量%的 MWCNTs-NH2 含量(100°C)下,观察到了最佳的形状记忆性能,回复率(Rf)为 93.54%,回复应力(Rr)为 87.09%,回复速率(V)为 4.3°/s。总之,这项全面的研究展示了功能化多壁碳纳米管对聚偏苯三酸乙酯(PBZ)形状记忆纳米复合材料的机械、热学、电学和形状记忆性能的影响。


Composites Science and Technology

Impact response of carbon fiber/aluminum honeycomb sandwich structures under multiple low-velocity loads

Shanshan Shi, Guoxin Wang, Chengtao Hu, Bingzhi Chen, Xiaozhi Hu, Zhi Sun

doi:10.1016/j.compscitech.2024.111027

 

多重低速载荷作用下碳纤维/铝蜂窝夹层结构的冲击响应

The carbon fiber/aluminum honeycomb sandwich structures are susceptible to repeated impacts from external objects, which can significantly affect their performance and safety in engineering applications. Firstly, this study prepares two sandwich panels with different face/core interfaces: plain carbon fiber/aluminum honeycomb panels and Kevlar short-fiber-toughened interfaces and then discusses the effects of impact location and interface properties on the panels' multi-impact and post-impact compression performance, utilizing Digital Image Correlation (DIC) to elucidate the toughening effect of Kevlar short fibers. Lastly, the study examines the relationship between pit depth and residual compressive strength in both the Kevlar short-fiber-toughened and plain specimens. Experimental observations and theoretical analysis further explain the deeper deformation mechanism of sandwich specimens after impact. The mechanism reveals the main reason for the independent CAI strength of toughened specimens with pit depth. The results indicate that impact location and interface properties significantly affect the multi-impact and post-impact compression performance of the honeycomb sandwich panels. The correlation between the residual compressive strength of the Kevlar short-fiber-toughened specimens and the variations in impact position and pit depth is weaker. This distinct behavior from the plain specimens is attributed to the effective suppression of delamination damage caused by pit depth due to Kevlar short-fiber interface toughening, as well as the effective controlling of the impact damage zone by composite fillets.

碳纤维/铝蜂窝夹层结构在工程应用中容易受到外界物体的反复冲击,严重影响其性能和安全性。本研究首先制备了两种面/芯界面不同的夹层板:普通碳纤维/铝蜂窝板和芳纶短纤维-增韧界面,然后讨论了冲击位置和界面性能对面板多次冲击和冲击后压缩性能的影响,利用数字图像相关(DIC)技术阐明了芳纶短纤维的增韧效果。最后,研究了凯夫拉纤维短纤维增韧和普通试样的坑深与残余抗压强度之间的关系。实验观察和理论分析进一步解释了夹层试件撞击后更深层次的变形机理。这一机理揭示了增韧试样随坑深变化而产生独立CAI强度的主要原因。结果表明,冲击位置和界面特性对蜂窝夹芯板的多次冲击和后冲击压缩性能有显著影响。凯夫拉纤维短纤维增韧试样的残余抗压强度与冲击位置和坑深变化的相关性较弱。这种不同于平面试样的行为是由于有效抑制了由Kevlar短纤维界面增韧引起的凹坑深度引起的分层损伤,以及复合圆角有效控制了冲击损伤区。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemInspireMAGNET振动断裂复合材料化学通用电子裂纹理论减材材料储能仿生控制
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【新文速递】2025年1月2日固体力学SCI期刊最新文章

今日更新:International Journal of Solids and Structures 1 篇,International Journal of Plasticity 4 篇,Thin-Walled Structures 6 篇International Journal of Solids and StructuresNon-local orthotropic damage-plastic model for 3D printed materialsDenis Linardi, Elisabetta Monaldo, Sonia Marfiadoi:10.1016/j.ijsolstr.2024.1132103D打印材料的非局部正交各向异性损伤塑性模型A non-local orthotropic damage and plasticity phenomenological model for 3D printed materials is presented. The model specifically refers to 3D printed structural elements realized with an extrusion-based technique and made with thermoplastic materials. The structural behaviour of the 3D printed component is described with a laminate finite element model based on the first-order shear deformation theory. Each layer of the laminate is described with a non-local orthotropic damage and plastic model. Indeed, the overall mechanical response of 3D printed materials is significantly influenced by plasticity and damage mechanisms that can lead to a range of failure modes from brittle-like to ductile. The proposed orthotropic damage model is based on the introduction of three different damage parameters. Each of them describes a specific damage mechanism, i.e. fiber breakage, fiber detachment and delamination, that is clearly visible from the analysis of the 3D printed samples subjected to experimental tests. Some applications are carried out and the numerical results are compared with experimental results available in literature, highlighting the effectiveness of the proposed modelling technique.提出了3D打印材料的非局部正交各向异性损伤和塑性现象学模型。该模型具体指的是采用基于挤出技术并由热塑性材料制成的3D打印结构元件。 采用基于一阶剪切变形理论的层合有限元模型描述了3D打印部件的结构行为。用非局部正交各向异性损伤和塑性模型描述了层合板的每一层。事实上,3D打印材料的整体力学响应受到塑性和损伤机制的显著影响,这可能导致从脆性到延性的一系列失效模式。提出的正交各向异性损伤模型是在引入三种不同损伤参数的基础上建立的。每一种都描述了一种特定的损伤机制,即纤维断裂、纤维脱离和分层,这从经过实验测试的3D打印样品的分析中可以清楚地看到。将数值结果与文献中的实验结果进行了比较,强调了所提出的建模技术的有效性。International Journal of PlasticityMultiscale modeling of the damage and fracture behaviours of TA15 titanium alloy with trimodal microstructureM.Y. Fei, P.F. Gao, Z.N. Lei, H.W. Li, M. Zhan, M.W. Fudoi:10.1016/j.ijplas.2024.104238 TA15钛合金三模态组织损伤断裂行为的多尺度模拟Trimodal microstructure, consisting of equiaxed α (αp), lamellar α (αl), and transformed β (βt), has become an ideal target microstructure of titanium alloys. However, the complex microstructure morphologies and the differences in mechanical property among the three constituent phases of the trimodal microstructure significantly influence its microscopic crack propagation behaviour and further affect its fracture toughness. To address this issue, a multiscale finite element (FE) model, including a microscopic crack propagation (micro-CP) model and a macroscopic fracture toughness (macro-FT) model, was established for analysis and prediction of the damage fracture behaviour and property of the trimodal microstructure. In this model, the deformation, damage and fracture behaviours of the trimodal microstructure at both micro and macro scales were described by bridging the constitutive laws of constituent phases and deformation responses. In tandem with this, the micro-CP model adopted a macro-micro nested structure, and the macro-FT model was developed based on a virtual fracture toughness test. Using the established multiscale FE model, the dependence of microscopic crack propagation and macroscopic fracture behaviours on the constituent phases of the trimodal microstructure was revealed. It is found that both αp and αl improved the path tortuosity and energy consumption of microscopic crack propagation, and αl decreased the microscopic crack propagation rate simultaneously. In addition, αp and αl contributed to the fracture toughness of the trimodal microstructure from both the intrinsic toughening mechanism (suppressing the heterogeneous deformation and damage and then decreasing the strength and increasing the plasticity) and the extrinsic toughening mechanism (increasing the tortuosity and energy consumption of crack propagation). The research provided an in-depth understanding of the damage and fracture behaviours of TA15 titanium alloy with the trimodal microstructure.由等轴α(αp)、层片α(αl)和转变β(βt)组成的三相微结构已成为钛合金的理想目标微结构。然而,这种复杂微结构的形态以及三相成分之间机械性能的差异显著影响其微观裂纹扩展行为,并进一步影响其断裂韧性。为解决这一问题,建立了包含微观裂纹扩展(micro-CP)模型和宏观断裂韧性(macro-FT)模型的多尺度有限元(FE)模型,用于分析和预测三相微结构的损伤断裂行为和性能。在该模型中,通过连接各组成相的本构定律和变形响应,描述了三相微结构在微观和宏观尺度上的变形、损伤和断裂行为。同时,micro-CP 模型采用了宏观-微观嵌套结构,而 macro-FT 模型则是基于虚拟断裂韧性测试开发的。利用已建立的多尺度有限元模型,揭示了三相微结构的组成相对于微观裂纹扩展和宏观断裂行为的影响。研究发现,αp 和 αl 均提高了微观裂纹扩展的路径曲折度和能量消耗,同时 αl 还降低了微观裂纹扩展速率。此外,αp 和 αl 从内在增韧机制(抑制异质变形和损伤,从而降低强度并提高塑性)和外在增韧机制(增加裂纹扩展的曲折度和能量消耗)两方面提高了三相微结构的断裂韧性。该研究为具有三相微结构的 TA15 钛合金的损伤和断裂行为提供了深入的理解。A thermodynamically consistent phase-field model for frictional fracture in rocksSijia Liu, Yunteng Wangdoi:10.1016/j.ijplas.2024.104220岩石摩擦断裂的热力学一致相场模型Frictional fracture phenomena in geological media are often closely related to fault instability in earthquakes and slip surface formation in geohazards. In this work, we propose a new phase-field model for capturing frictional fractures in pressure-sensitive geomaterials. Our model has three novel features: (i) a thermodynamically consistent energetic interface for contact and friction conditions; (ii) incorporation of a level set function to couple phase-field evolution and frictional-contact slips; and (iii) a transition from stored energy to yielding for describing different plastic-like frictional stick–slip fractures. Based on the energy conservation law and a variational inequality of virtual work, we formulate the governing equations for frictional fractures, including the dynamic equilibrium equation, phase-field evolution law, and most importantly, frictional interface plastic-like driving forces. We also present a robust numerical technique to handle the spatiotemporal formation and evolution of frictional fractures in rocks. We validate the model by simulating several benchmark examples. Our model is shown to reproduce both frictional stick and slip phenomena in rocks. We also apply this model to study the effect of confining pressure on frictional crack initiation and propagation in rocks, which helps us better understand the deep mechanisms of frictional fracture.地质介质中的摩擦断裂现象往往与地震中的断层失稳和地质灾害中的滑面形成密切相关。在这项工作中,我们提出了一种新的相场模型,用于捕获压力敏感岩土材料中的摩擦裂缝。我们的模型具有三个新特征:(i)接触和摩擦条件下的热力学一致的能量界面;(ii)结合一个水平集函数来耦合相场演化和摩擦接触滑移;(3)从存储能量到屈服的过渡,用于描述不同的类塑性粘滑摩擦裂缝。基于能量守恒定律和虚功的变分不等式,建立了摩擦断裂的控制方程,包括动力学平衡方程、相场演化定律,以及最重要的摩擦界面类塑性驱动力。我们还提出了一种强大的数值技术来处理岩石中摩擦裂缝的时空形成和演化。我们通过模拟几个基准示例来验证模型。我们的模型被证明可以再现岩石中的摩擦粘和滑动现象。我们还应用该模型研究了围压对岩石摩擦裂纹萌生和扩展的影响,这有助于我们更好地理解摩擦破裂的深层机制。Advancing material simulations: Physics-Informed Neural Networks and Object-Oriented Crystal Plasticity Finite Element MethodsShahriyar Keshavarz, Yuwei Mao, Andrew C.E. Reid, Ankit Agrawaldoi:10.1016/j.ijplas.2024.104221 先进的材料模拟:物理信息神经网络和面向对象的晶体塑性有限元方法An innovative method for predicting the behavior of crystalline materials is presented by integrating Physics-Informed Neural Networks (PINNs) with an object-oriented Crystal Plasticity Finite Element (CPFE) code within a large deformation framework. The CPFE platform is utilized to generate reference data for training the PINNs, ensuring precise and fast predictions of material responses. The object-oriented design of the CPFE system facilitates the coherent incorporation of complex constitutive models and numerical methods, enhancing simulation flexibility and scalability. To demonstrate the adaptability of this approach, two problems are addressed: a fundamental power-law and a complex dislocation density-based constitutive models for predicting the behavior of Ni3Al-based alloys. Both models are implemented within an object-oriented CPFE system powered by its flexible plug-in architecture. The resulting PINN model accurately captures intricate deformation mechanisms in crystalline materials, as validated through comparisons with CPFE simulations and experimental data. This work offers a promising alternative for efficient and accurate material behavior prediction, paving the way for advanced simulations in materials science.本文提出了一种创新方法,通过将物理信息神经网络(PINNs)与面向对象的晶体塑性有限元(CPFE)代码集成在一个大变形框架内,来预测晶体材料的行为。CPFE 平台用于生成训练 PINNs 的参考数据,从而确保对材料响应进行精确且快速的预测。CPFE 系统的面向对象设计有助于将复杂的本构模型和数值方法进行一致整合,从而提高模拟的灵活性和可扩展性。为了展示该方法的适应性,解决了两个问题:一个是基本的幂律模型,另一个是基于位错密度的复杂本构模型,用于预测 Ni3Al 基合金的行为。这两个模型均在由其灵活的插件架构支持的面向对象 CPFE 系统中实现。通过与 CPFE 模拟和实验数据的比较验证,所得的 PINN 模型能够准确捕捉晶体材料中复杂的变形机制。这项工作为高效且准确地预测材料性能提供了一种很有前景的替代方案,为材料科学中的高级模拟铺平了道路。Modeling inter- and intra-granular dislocation transport using crystal plasticitySubhendu Chakraborty, Abigail Hunter, D.J. Luscherdoi:10.1016/j.ijplas.2024.104222 利用晶体塑性模拟晶间和晶内位错输运This work presents the development of a crystal plasticity material model that incorporates both dislocation transport within grains and dislocation transfer across grain boundaries. This model has been implemented in the open-source finite element code MOOSE. In addition, a novel geometry-based criterion is developed to determine the direction of dislocation transfer across grain boundaries. The transfer criterion incorporates the geometric features of the grain boundary, such as the grain boundary plane normal, and its misorientation, which is accounted for through the orientation of the incoming and outgoing slip systems. The model is tested with several cases, including a copper single crystal, bi-crystal, and polycrystal. The development of the transfer criterion, implementation of the model, and its application to these test cases are discussed in detail.这项工作提出了晶体塑性材料模型的发展,该模型结合了晶粒内的位错传递和跨晶界的位错传递。该模型已在开源有限元代码MOOSE中实现。此外,提出了一种新的基于几何的判据来确定位错跨晶界转移的方向。传递准则结合了晶界的几何特征,如晶界平面法向及其取向偏差,这是通过进出滑动系统的取向来解释的。该模型在几种情况下进行了测试,包括铜单晶,双晶和多晶。详细讨论了转移准则的开发、模型的实现及其在这些测试用例中的应用。Thin-Walled StructuresNovel resonator concept for improved performance of locally resonant based metamaterialsF.A. Pires, R.F. Boukadia, M. Wandel, C. Thomas, E. Deckers, W. Desmet, C. Claeysdoi:10.1016/j.tws.2024.112866改进局部共振基超材料性能的新谐振器概念In the context of noise control engineering, locally resonant metamaterials (LRMs) have gained significant research attention over the past two decades due to their ability to combine lightweight, compact design with excellent noise and vibration insulation performance in targeted frequency ranges, known as stop bands. This paper proposes a novel resonator concept that achieves a high modal effective mass (MEF) for out-of-plane bending, aiming to widen the stop bands in LRMs. First, the dynamic motion of an idealized double-lever system, which inspired the resonator design, is analyzed. Then, a realizable resonator design is presented, along with an optimization scheme that maximizes the MEF, achieving values as high as 96.5%. The proposed resonator concept is used to develop an LRM solution to enhance the acoustic insulation performance of a structure relevant to the aerospace industry, yielding improvements of up to 9 dB in the frequency band of interest. Experimental results demonstrate that the designed LRM solution significantly improves the vibro-acoustic response of the system. Future work will consider additional aspects of the optimization process, including manufacturing constraints, costs, and robustness.在噪声控制工程的背景下,局部谐振超材料(lrm)在过去的二十年中获得了重要的研究关注,因为它们能够将轻质,紧凑的设计与在目标频率范围内(称为阻挡带)的优异噪声和振动绝缘性能相结合。本文提出了一种新的谐振器概念,实现了高模态有效质量(MEF)的面外弯曲,旨在扩大lrm中的阻带。首先,分析了理想双杠杆系统的动态运动,该系统启发了谐振器的设计。然后,提出了一个可实现的谐振器设计,以及一个最大化MEF的优化方案,使MEF达到高达96.5%的值。提出的谐振器概念用于开发LRM解决方案,以增强与航空航天工业相关的结构的隔音性能,在感兴趣的频带内产生高达9 dB的改进。实验结果表明,所设计的LRM方案显著改善了系统的声振响应。未来的工作将考虑优化过程的其他方面,包括制造限制、成本和鲁棒性。Torsional Restraint of Roof Sheeting on Cold-Formed Steel Hat SectionsJohn Papangelis, Chong Li, Liao Yi, Fangyuan Yuedoi:10.1016/j.tws.2024.112882冷弯型钢顶板的抗扭约束Cold-formed steel hat sections are commonly used as thin-walled beams to support thin profiled roof sheeting. Cold-formed steel sections are usually thinner than hot-rolled sections and have modes of failure which are not commonly encountered in hot-rolled structural steel design. The individual plate elements in cold-formed steel hat sections are normally thin compared with their width and so local and distortional buckling may occur before section yielding. In addition, cold-formed steel hat sections may undergo flexural-torsional buckling because of their low torsional stiffness. For cold-formed steel hat sections which may fail by flexural-torsional buckling, the roof sheeting provides a torsional restraint which can increase the flexural-torsional buckling capacity. Previous research has focused on determining the torsional restraint provided by roof sheeting to C and Z section purlins but no research has been done for hat sections. This paper describes a unique test procedure to determine the value of the torsional restraint provided by roof sheeting on hat sections for 12 different combinations of hat sections and roof sheeting profiles. Three tests for each combination were performed, resulting in a total of 36 tests. The results show that the torsional restraint increases as the depth or thickness of the hat section is increased and also when the sheeting thickness increases. A finite element flexural-torsional buckling analysis is also described for analysing hat sections with elastic continuous restraints, such as those provided by roof sheeting. The finite element analysis is validated with the theoretical solution for the flexural-torsional buckling of hat sections with torsional restraint and diaphragm shear restraint. An example is described to demonstrate the effect of torsional restraint and diaphragm shear restraint on the flexural-torsional buckling of hat sections subjected to uniformly distributed load. It is shown that including these restraints in the analysis will result in a significant increase in the flexural-torsional buckling load and the design load capacity.冷弯型钢帽截面通常用作薄壁梁来支撑薄型屋面板。冷弯型钢通常比热轧型钢更薄,并且具有热轧型钢设计中不常见的失效模式。冷弯型钢帽截面中的单个板单元通常比其宽度薄,因此在截面屈服之前可能发生局部扭曲屈曲。此外,冷弯型钢帽截面由于其扭转刚度低,可能发生弯扭屈曲。对于可能受弯扭屈曲破坏的冷弯型钢帽型钢,顶板提供了扭转约束,可以增加弯扭屈曲能力。以往的研究主要集中在确定顶板对C、Z截面檩条的抗扭约束上,但对C、Z截面檩条的抗扭约束尚未进行研究。本文描述了一种独特的测试程序,用于确定12种不同的帽型和车顶板型的组合,车顶板对帽型提供的扭转约束值。对每种组合进行了三次测试,总共进行了36次测试。结果表明,扭转约束随帽段深度或厚度的增加而增大,随板层厚度的增加而增大。有限元弯扭屈曲分析也描述了分析具有弹性连续约束的帽段,例如由屋面板提供的那些。通过有限元分析验证了具有扭转约束和膜片剪切约束的帽形截面弯曲-扭转屈曲的理论解。通过算例验证了扭转约束和膜片剪切约束对均布荷载作用下帽形截面弯扭屈曲的影响。结果表明,在分析中加入这些约束将导致弯扭屈曲载荷和设计载荷能力的显著增加。Nonlinear Vibration-acoustic Analysis of the Coupled System of Flexible Cylindrical Shell Foundation and HSLDS Vibration IsolatorJunfeng Liu, Jingjun Lou, Kai Chai, Qingchao Yangdoi:10.1016/j.tws.2024.112896柔性圆柱壳基础与HSLDS隔振器耦合系统的非线性振动-声分析This paper is concerned with the vibration and acoustic radiation problems of the coupled system of mass oscillator, high-static-low-dynamic stiffness (HSLDS) isolator and flexible stiffened cylindrical shell immersed in an infinite acoustic medium. A frequency domain numerical calculation method is proposed. The HSLDS isolator is fitted by odd-order polynomials, and the periodic solution of the deformation of the HSLDS isolator spring is expanded into a superimposed harmonic function. The dynamic stiffness matrix of the stiffened cylindrical shell is established by the wave propagation method, and the force of the external acoustic fluid on the shell is introduced by the Helmholtz boundary integral equation, and the acoustic radiation calculation is carried out. Based on the force and displacement continuity conditions and the interface compatibility conditions between the structure and the acoustic medium, the dynamic stiffness matrix of the mass-spring-damper system, the stiffened cylindrical shell and the external fluid coupling is established, and the harmonic balance method and Newton-like solver are used to solve it. By comparing the solutions of the finite element method and the boundary element method, the accuracy of the method is verified, and the predicted results are in good agreement with the reference results. The effects of circumferential wave modes and the number of axially discrete 3-node elements of cylindrical shells on the vibration and radiated acoustic response of nonlinear coupling systems are studied. The effects of HSLDS isolators, damping and the amplitude of external loads on the vibration and acoustic radiation behavior of the coupling system are studied, and the influences of HSLD isolators on shell vibration and acoustic radiation propagation are analyzed, which can provide useful guidance for the vibration isolation design and optimization of underwater rigid-flexible coupling systems.研究了质量振子、高静低动刚度(HSLDS)隔振器和柔性加筋圆柱壳在无限大声介质中的耦合系统的振动和声辐射问题。提出了一种频域数值计算方法。采用奇阶多项式对HSLDS隔振器进行拟合,将HSLDS隔振器弹簧变形的周期解展开为叠加谐波函数。采用波传播法建立加劲圆柱壳的动力刚度矩阵,采用亥姆霍兹边界积分方程引入外声流体对壳体的作用力,并进行声辐射计算。基于力和位移连续条件和结构与声介质界面相容条件,建立了质量-弹簧-阻尼器系统、加劲圆柱壳和外部流体耦合的动态刚度矩阵,并采用谐波平衡法和类牛顿求解器对其进行求解。通过比较有限元法和边界元法的解,验证了该方法的准确性,预测结果与参考结果吻合较好。研究了圆柱壳的周向波模态和轴向离散3节点单元数对非线性耦合系统振动和辐射声响应的影响。研究了HSLD隔振器、阻尼和外载荷幅值对耦合系统振动和声辐射特性的影响,分析了HSLD隔振器对壳体振动和声辐射传播的影响,为水下刚柔耦合系统的隔振设计和优化提供了有益的指导。Impact properties and damage assessment of unidirectional aramid/carbon fiber hybrid reinforced polymer compositesXiaogang Liu, Weichen Kong, Siqi Song, Anni Wangdoi:10.1016/j.tws.2024.112898单向芳纶/碳纤维杂化增强聚合物复合材料的冲击性能及损伤评估To improve the impact resistance of unidirectional carbon fiber-reinforced polymer (CFRP) composites, unidirectional aramid/carbon fiber hybrid-reinforced polymer (A/CFHRP) composites were developed. Through a series of low-speed impact tests, ultrasonic scanning, CT scanning, and post-impact compression tests, the study examined the impact response, damage modes, and severity of damage in A/CFHRP composites with varying fiber volume ratios. Additionally, the residual properties after impact were assessed. The findings revealed that the incorporation of aramid fibers significantly enhances the impact resistance of CFRP. As the aramid fiber content increased, the specific energy absorption of A/CFHRP initially increased and then decreased, indicating an upper limit to the improvement in impact resistance provided by aramid, which is dependent on the impact energy. The maximum specific energy absorption of A/CFHRP is 46% higher than that of CFRP. The introduction of aramid fibers transforms the damage mode of CFRP from brittle fracture to interlayer delamination and interface debonding, thereby preserving higher structural integrity and superior post-impact residual performance. After 10J impact energy, the strength retention rate of A/CFRP after impact is 81.2% higher than that of CFRP; after 50J impact energy, the strength retention rate of A/CFRP after impact is 37.4% higher than that of CFRP为了提高单向碳纤维增强聚合物(CFRP)复合材料的抗冲击性能,研制了单向芳纶/碳纤维混合增强聚合物(A/CFHRP)复合材料。通过一系列低速冲击试验、超声扫描、CT扫描和冲击后压缩试验,研究了不同纤维体积比下a /CFHRP复合材料的冲击响应、损伤模式和损伤严重程度。此外,还对冲击后的残余性能进行了评估。结果表明,芳纶纤维的掺入显著提高了CFRP的抗冲击性。随着芳纶纤维含量的增加,A/CFHRP的比能量吸收率先升高后降低,说明芳纶提高抗冲击性能的能力有一个上限,这取决于冲击能量。A/CFHRP的最大比能量吸收比CFRP高46%。芳纶纤维的引入使CFRP的损伤模式从脆性断裂转变为层间分层和界面脱粘,从而保持了较高的结构完整性和优异的冲击后残留性能。10J冲击能量后,A/CFRP的强度保持率比CFRP高81.2%;50J冲击能量后,A/CFRP的强度保持率比CFRP高37.4%Material performance, manufacturing methods, and engineering applications in aviation of Carbon fiber reinforced polymers: A comprehensive reviewXiangyu Xu, Gongqiu Peng, Baoyan Zhang, Fenghui Shi, Liang Gao, Junpeng Gaodoi:10.1016/j.tws.2024.112899碳纤维增强聚合物材料性能、制造方法及其在航空工程中的应用综述Carbon fiber reinforced polymers (CFRP) is becoming the predominant material in the aviation industry due to its excellent performance including light weight, high specific strength, high specific modulus, excellent fatigue fracture resistance, corrosion resistance, strong design flexibility, and suitability for the overall molding of large components. The application parts of CFRP are almost all over the aircrafts, such as wings, tails, fuselages, landing gears, engines and other parts. The proportion of fiber reinforced polymer matrix composites (PMCs) has become an essential indicator of aircrafts in practical engineering applications. This paper provides an overview of the background and evolution of CFRPs followed by an introduction to the material properties of carbon fibers (CFs) and different resin matrices. Subsequently, the principle and characteristics of the commonly used manufacturing methods of CFRP are presented. Next, the material performance of both thermosetting and thermoplastic CFRP are provided. Finally, the applications in aviation and the developing trends of CFRP are described. This review aims to offer researchers a comprehensive reference on the material performance and applications of CFRP within the aviation field while providing valuable insights for future PMC advancements.碳纤维增强聚合物(CFRP)具有重量轻、比强度高、比模量高、抗疲劳断裂、耐腐蚀、设计柔韧性强、适合大型部件整体成型等优点,正成为航空工业的主导材料。CFRP的应用部件几乎遍及飞机的各个部位,如机翼、尾翼、机身、起落架、发动机等部件。在实际工程应用中,纤维增强聚合物基复合材料(PMCs)的比例已成为飞机性能的重要指标。本文概述了碳纤维纤维的背景和发展,然后介绍了碳纤维(CFs)和不同树脂基体的材料特性。随后,介绍了碳纤维增强塑料的常用制造方法的原理和特点。其次,介绍了热固性和热塑性CFRP的材料性能。最后介绍了碳纤维布在航空领域的应用及发展趋势。本综述旨在为研究人员提供碳纤维增强塑料在航空领域的材料性能和应用的综合参考,同时为未来碳纤维增强塑料的发展提供有价值的见解。From the Yoshimura origami pattern to foldable structures: Exploration of crease designZhitong Fei, Dongyang Xu, Yanzhi Zhao, Zhen Han, Linquan Song, Ruibao Ma, Yulin Guodoi:10.1016/j.tws.2024.112888从吉村折纸图案到可折叠结构:折痕设计的探索Crease design is crucial to the function and application scope of origami projects; however, for the Yoshimura origami pattern, the connection between origami two-dimensional (2D) creases and three-dimensional (3D) forms has not been established, which greatly limits the research and application of origami structures. In this paper, a crease design theory for the Yoshimura origami pattern is proposed to create 3D foldable origami structures. Afterward, the flat origami folding process is described, and the corresponding end trajectory equations are derived from a crease chain folding analysis performed on the element block and the expansion block. Next, the positional and angular constraint equations for single-variable, double-variable, and triple-variable foldable forms with only element blocks are systematically discussed. Finally, a detailed folding simulation analysis is performed based on the positional and angular constraint equations, and the foldable form family diagrams with the corresponding angular value intersection curve constraints are summarized. The theory is verified by finite element programs and experiments. This work provides an effective theory for the design of origami creases and new ideas and methods for the study of the Yoshimura pattern and other origami patterns.折痕设计对折纸项目的功能和应用范围至关重要;然而,对于吉村折纸图案,折纸二维(2D)折痕与三维(3D)折痕之间的联系尚未建立,这极大地限制了折纸结构的研究和应用。本文提出了一种吉村折纸图案的折痕设计理论,用于创建三维可折叠折纸结构。然后,描述了平面折纸的折叠过程,并通过对单元块和膨胀块进行折痕链折叠分析,推导了相应的末端轨迹方程。其次,系统地讨论了单变量、双变量和三变量仅包含单元块的可折叠形式的位置和角度约束方程。最后,基于位置约束方程和角度约束方程进行了详细的折叠仿真分析,总结了具有相应角值相交曲线约束的可折叠形式族图。通过有限元程序和实验对理论进行了验证。本工作为折纸折痕的设计提供了有效的理论依据,也为吉村图案等折纸图案的研究提供了新的思路和方法。来源:复合材料力学仿真Composites FEM

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