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【新文速递】2024年3月3日复合材料SCI期刊最新文章

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

Composite Structures

Thermo-Mechanical analysis of laminated Doubly-Curved Shells: Higher order Equivalent Layer-Wise formulation

Francesco Tornabene, Matteo Viscoti, Rossana Dimitri

doi:10.1016/j.compstruct.2024.117995

层叠双曲面壳体的热力学分析:高阶等效层智公式

The paper presents a refined two-dimensional formulation for the thermo-mechanical analysis of laminated doubly-curved shell structures under thermodynamic equilibrium conditions. Both the kinematic configuration variables and the temperature variation with respect to the natural equilibrium state are described with a generalized formulation, following the Equivalent Layer-Wise (ELW) approach employing higher order polynomials, along with some proper zigzag functions. The governing equations are derived from the stationary configuration of the Helmholtz free energy of the system, and a semi-analytical solution is found. In the post-processing phase, the Fourier-based Generalized Differential Quadrature (F-GDQ) is applied to recover the actual three-dimensional response of the doubly-curved shell solid, and very accurate results are obtained for the quantities of both mechanical and heat conduction problems. In addition, the integrals occurring in the theory are performed numerically with the Taylor-based Generalized Integral Quadrature (GTIQ), showing a high level of accuracy with a reduced number of sample points. The model is validated in some case studies where the accuracy of the model is shown, and the numerical predictions are successfully compared with those of refined three-dimensional numerical simulations. After that, an extensive set of parametric investigations is reported, pointing out the effects of the panel’s curvature, lamination schemes and different levels of coupling on the thermo-mechanical structural behavior of the investigated panels.

本文针对热力学平衡条件下的层叠双曲面壳体结构的热机械分析,提出了一种改进的二维公式。运动构型变量和相对于自然平衡状态的温度变化均采用通用公式进行描述,该公式采用了高阶多项式和一些适当的之字形函数的 "等效分层"(ELW)方法。根据系统的亥姆霍兹自由能的静态配置推导出控制方程,并找到半解析解。在后处理阶段,应用基于傅立叶的广义微分正交(F-GDQ)来恢复双曲面壳体固体的实际三维响应,并获得了机械和热传导问题的非常精确的结果。此外,理论中出现的积分采用基于泰勒的广义积分正交(GTIQ)进行数值计算,在样本点数量减少的情况下显示出很高的精度。该模型在一些案例研究中得到了验证,证明了模型的准确性,并成功地将数值预测与精细的三维数值模拟进行了比较。随后,报告了一系列广泛的参数研究,指出了面板的曲率、层压方案和不同程度的耦合对所研究面板的热机械结构行为的影响。


Composites Part A: Applied Science and Manufacturing

Lightweight zirconium modified carbon–carbon composites with excellent microwave absorption and mechanical properties

Weikang Tang, Shun Dong, Tangyin Cui, Jianqiang Xin, Yongshuai Xie, Guiqing Chen, Changqing Hong, Xinghong Zhang

doi:10.1016/j.compositesa.2024.108102

具有优异微波吸收能力和机械性能的轻质锆改性碳-碳复合材料

With the rapid development of space technology, multi-functional materials with advantages such as heat insulation, lightweight, and electromagnetic (EM) wave absorption have gained broad application prospects. Since porous carbon fiber reinforced carbon (C/C) composites often have lightweight and high heat insulation properties, improving their mechanical and electromagnetic wave absorbing properties will significantly expand their application. In this study, a new kind of zirconium-modified C/C (Zr-C/C) composites prepared by polymer infiltration and pyrolysis using zirconium-modified phenolic resin is presented. By adjusting the content of Zr, the compressive strengths of the composites are increased up to 48% compared with the composites without Zr, while the thermal insulation properties are little changed. The incorporation of zirconium can make the composites exhibit better microwave absorption performance to some extent, and Zr-C/C composites with 10% zirconium have the best microwave absorption performance among all the samples. The excellent electromagnetic wave absorption performance of Zr-C/C composites is attributed to the enhanced interfacial polarization effect and the improved electrical conductivities of the material due to its internal carbon microsphere structure. Multi-functional Zr-C/C composites that combine lightweight, high thermal insulation, high compressive strength, and high electromagnetic wave absorption have obvious applications in fields such as stealth aircraft. Therefore, this work provides a new way to prepare multi-functional materials.

随着航天技术的飞速发展,具有隔热、轻质和吸收电磁波等优点的多功能材料获得了广阔的应用前景。由于多孔碳纤维增强碳(C/C)复合材料通常具有轻质和高隔热性能,因此改善其机械性能和电磁波吸收性能将大大拓展其应用领域。本研究利用锆改性酚醛树脂,通过聚合物浸渗和热解制备了一种新型锆改性碳纤维增强碳(C/C)复合材料(Zr-C/C)。与不含锆的复合材料相比,通过调整锆的含量,复合材料的抗压强度提高了 48%,而隔热性能变化不大。锆的加入能在一定程度上使复合材料表现出更好的微波吸收性能,其中含 10%锆的 Zr-C/C 复合材料的微波吸收性能是所有样品中最好的。Zr-C/C 复合材料优异的电磁波吸收性能得益于界面极化效应的增强以及材料内部碳微球结构带来的导电性能的改善。集轻质、高隔热、高抗压强度和高电磁波吸收能力于一身的多功能 Zr-C/C 复合材料在隐形飞机等领域具有明显的应用前景。因此,这项工作为制备多功能材料提供了一条新途径。


Composites Part B: Engineering

The role of nanoclay in processing immiscible polypropylene and poly (ethylene terephthalate) waste blends using twin screw extrusion

Shawn Martey, Mansoureh Jamalzadeh, Wan-Ting Chen, Margaret J. Sobkowicz

doi:10.1016/j.compositesb.2024.111320

 

纳米粘土在使用双螺杆挤出机加工不相溶聚丙烯和聚(乙烯对苯二甲酸乙二酯)废料混合物中的作用

Polypropylene and poly(ethylene terephthalate) waste were blended with different types of nanoclay (cloisite Na+, cloisite 20A and CT4270) to understand the role of nanoclay in immiscible polymer blends. The blend morphology was investigated using scanning electron microscopy, the dispersion of the nanoclay was characterized using wide angle x-ray diffraction (WAXD) and rheology. WAXD results showed partial exfoliation for cloisite Na+ and intercalation for cloisite 20A and CT4270. It was predicted that cloisite Na + settled in the PET phase while cloisite 20A settled at the interface of PP and PET. Morphology analysis showed that increasing the concentration of nanoclay in the blend decreased the droplet size. The nanoclay was shown to inhibit coalescence of the droplets causing a decrease due to its rigidity.

将聚丙烯和聚对苯二甲酸乙二酯废料与不同类型的纳米土(cloisite Na+、cloisite 20A 和 CT4270)混合,以了解纳米土在不相溶聚合物共混物中的作用。使用扫描电子显微镜研究了共混物的形态,使用广角 X 射线衍射(WAXD)和流变学表征了纳米土的分散性。WAXD 结果显示,钙钛矿 Na+ 部分剥离,而钙钛矿 20A 和 CT4270 则发生了插层。据预测,loisite Na + 沉淀在 PET 相中,而 cloisite 20A 沉淀在 PP 和 PET 的界面上。形态分析表明,增加混合物中纳米土的浓度会减小液滴尺寸。纳米粘土可抑制液滴的凝聚,从而降低液滴的硬度。


Influence of unidirectional composite failure envelope shape on predicting compressive failure of a laminate with a filled hole

Ivan R. Cózar, José M. Guerrero, Pere Maimí, Albertino Arteiro, Santiago García-Rodríguez, Mélanie Herman, Albert Turon

doi:10.1016/j.compositesb.2024.111352

单向复合材料破坏包络线形状对带填充孔层压破坏预测的影响

In recent decades, several computational models have emerged at the mesoscale for predicting the failure development and strength of composite materials. Nevertheless, the intricate failure mechanisms of composites pose a formidable challenge in developing models capable of consistently reproducing diverse sets of experimental data. Furthermore, the absence of standardised multiaxial tests has hindered consensus on failure envelopes and criteria for composites. In this work, an in-house constitutive model implemented in a finite element code is employed to predict the failure strength of several filled hole compressive carbon/epoxy experimental tests, varying in stacking sequences, sizes, bolt preloads, and other parameters. The influence the selected failure criterion has on the predictions is analysed. The findings indicate a large impact of the failure envelope on both the ultimate compressive strength and developed failure mechanisms. Therefore, the correct adjustment of the failure criteria can be as relevant as defining accurately the material input parameters. These results emphasise the importance of accurately establishing failure envelopes, rather than overemphasising the development of complex models.

近几十年来,在中尺度上出现了一些用于预测复合材料失效发展和强度的计算模型。然而,复合材料的失效机理错综复杂,这对开发能够持续再现各种实验数据的模型提出了严峻的挑战。此外,标准化多轴测试的缺乏也阻碍了对复合材料失效包络和标准达成共识。在这项工作中,采用了一个在有限元代码中实施的内部构成模型来预测多个填充孔压缩碳/环氧实验测试的破坏强度,这些测试在堆叠顺序、尺寸、螺栓预紧力和其他参数方面各不相同。分析了所选失效准则对预测结果的影响。研究结果表明,失效包络线对极限抗压强度和失效机理都有很大影响。因此,正确调整失效标准与准确定义材料输入参数同样重要。这些结果强调了准确确定破坏包络的重要性,而不是过分强调复杂模型的开发。


Composites Science and Technology

A honeycomb-inspired carboxymethyl chitosan-covalently link NH2-black phosphorene biobased cellulose green nanocomposites with tremendously enhancement fire safety and thermal conductivity

Kunxin Wang, Zhencai Qu, Hui Yang, Guoming Yuan, Xiu-e Li, Zhijun Liu, Yanhan Tao, Yang Li, Kun Wu, Jun Shi

doi:10.1016/j.compscitech.2024.110535

 

一种蜂窝状羧甲基壳聚糖共价连接 NH2-黑磷烯生物基纤维素绿色纳米复合材料,可大幅提高防火安全性和导热性能

Biobased carboxymethyl chitosan-modified black phosphorene (BP-CMC) was prepared through an amidation reaction between amino group functionalized black phosphorene (NH2-BP) and CMC. Density functional theory (DTF) express that the adsorption energy between urea and phosphene is −6.28 eV, indicating a strong interaction. The resulting BP-CMC was further applied to reinforce the mechanical, flame-retardant and thermal conductivity performance of honeycomb cellulose nanofiber (CNF) film via vacuum filtration. Cone calorimetry test (CCT) result exhibits that the introduction of 30 wt% BP-CMC significantly promoted the fire safety of CNF. For instance, a 98.41% reduction in smoke production rate (SPR), 92.00 % decline in CO release and a 61.31% decrease in heat release rate (HRR) were observed compared to neat CNF. Furthermore, Thermogravimetric infrared (TG-IR) indicates a significant decrease in the release of flammable gases. Raman spectra verify that the incorporation of 30 wt% BP-CMC improves the graphitization degree of residual chars, thus limiting the transfer of heat and oxygen. The improvement in fire safety is attributed to the formation of an intumescent flame-retardant system, which is rich in carbon source (CMC), acid source (BP) and gas source (amino). Simultaneously, the introduction of 30 wt% BP-CMC into CNF leads to considerable enhancement in thermal conductivity (up to 17.49 %), thermal diffusion (utmost to 43.45 %) and heat capacity (increased by 19.23 %). Moreover, the 30 wt % addition of BP-CMC into CNF possesses excellent mechanical properties with the improvement of toughness (increased by 143.50 %) and tensile strength (increased by 140.90 %). This strategy not only provides a new strategy for functionalizing BP but also upgrades the application potential of BP nanosheets in the fire safety of polymer composite films.

通过氨基官能化黑磷烯(NH2-BP)与 CMC 的酰胺化反应制备了生物基羧甲基壳聚糖改性黑磷烯(BP-CMC)。密度泛函理论(DTF)表明,脲与磷烯之间的吸附能为 -6.28 eV,表明存在很强的相互作用。通过真空过滤,得到的 BP-CMC 进一步用于增强蜂窝纤维素纳米纤维(CNF)薄膜的机械、阻燃和导热性能。锥形量热试验(CCT)结果表明,30 wt% BP-CMC 的引入显著提高了 CNF 的防火安全性。例如,与纯 CNF 相比,产烟率(SPR)降低了 98.41%,一氧化碳释放量减少了 92.00%,热释放率(HRR)降低了 61.31%。此外,热重红外(TG-IR)显示可燃气体的释放量显著减少。拉曼光谱验证了 30 wt% BP-CMC 的加入提高了残留炭的石墨化程度,从而限制了热量和氧气的传递。防火安全性的提高归功于富含碳源(CMC)、酸源(BP)和气源(氨基)的膨胀阻燃体系的形成。同时,在 CNF 中引入 30 wt%的 BP-CMC 可显著提高导热率(高达 17.49%)、热扩散率(高达 43.45%)和热容量(提高 19.23%)。此外,在氯化萘纤维中添加 30 wt % 的 BP-CMC 可提高韧性(提高 143.50 %)和拉伸强度(提高 140.90 %),从而具有优异的机械性能。这种策略不仅为 BP 功能化提供了一种新策略,还提升了 BP 纳米片在聚合物复合薄膜防火安全方面的应用潜力。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemInspireMAGNET复合材料通用航天电子ECAD理论材料控制试验曲面螺栓
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首次发布时间:2024-11-06
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【新文速递】2024年2月21日固体力学SCI期刊最新文章

今日更新:Journal of the Mechanics and Physics of Solids 1 篇,Thin-Walled Structures 8 篇Journal of the Mechanics and Physics of SolidsFluid-injection control on energy partitioning during the earthquake cycleMaryam Alghannam, Hector Gomez, Ruben Juanesdoi:10.1016/j.jmps.2024.105580注入流体对地震周期中能量分配的控制During an earthquake, the elastic energy stored in the Earth is released as frictional energy and radiated energy in the form of seismic waves. The partitioning of energy released during an earthquake gives an indication of the overall size of the earthquake and its potential for damage to man-made structures. Here, we perform an energy analysis of fluid-injection-induced earthquakes using a single-degree-of-freedom spring poroslider and rate-and-state friction. We show that seismic radiation can be modeled within the single-degree-of-freedom spring-slider by adding a radiation damping term. We then use it to study fluid injection and assess its effects on the energy partitioning during induced and triggered earthquakes. We find that: (1) seismic efficiency, stress drop, and total slip are directly influenced by the rate of increase in pore pressure, (2) the ratio of elastic energy stored in the skeleton to injection energy is low and is influenced by the rate of fluid injection, (3) seismic injection efficiency is also low and is lower for induced earthquakes compared to triggered ones, and (4) fluid injection leads to bigger and potentially more damaging earthquakes overall.地震时,地球中储存的弹性能量会以摩擦能和地震波的形式释放出来。地震过程中释放的能量分区可显示地震的总体规模及其对人造结构造成破坏的可能性。在此,我们使用单自由度弹簧孔滑块和速率与状态摩擦对注入流体引发的地震进行了能量分析。我们证明,地震辐射可以通过添加辐射阻尼项在单自由度弹簧滑块中建模。然后,我们用它来研究流体注入,并评估其对诱发地震和触发地震期间能量分配的影响。我们发现(1) 地震效率、应力下降和总滑移直接受孔隙压力增加速率的影响;(2) 骨架中存储的弹性能量与注入能量的比率较低,且受流体注入速率的影响;(3) 地震注入效率也较低,且诱发地震的注入效率低于触发地震;(4) 流体注入会导致更大、潜在破坏性更强的地震。Thin-Walled StructuresDynamic stiffness method and CUF-based component-wise theories applied to free vibration analysis of solid beams, thin-walled structures and reinforced panelsXiao Liu, Alfonso Pagani, Erasmo Carrera, Xiang Liudoi:10.1016/j.tws.2024.111707应用于实心梁、薄壁结构和加固板自由振动分析的动态刚度法和基于 CUF 的分量-分项理论In this paper, an exact dynamic stiffness formulation using higher-order theories with displacement variables only is presented and subsequently used to investigate the free vibration characteristics of solid beams, thin-walled structures and reinforced panel structures. In essence, higher-order displacement fields are developed by using the Carrera unified formulation (CUF), and by discretizing the cross-section kinematics with bilinear, cubic and fourth-order Lagrange polynomials. In particular, the component-wise (CW) approach based on Lagrange expansion is applied in which the solid part and thin-walled part are considered as two independent components that can be assembled. The principle of virtual displacements is used to derive the governing differential equations and the associated natural boundary conditions. An exact dynamic stiffness matrix is then developed by relating the amplitudes of harmonically varying loads to those of the responses. The explicit terms of the dynamic stiffness matrices are also presented. The Wittrick–Williams algorithm of the dynamic stiffness method (DSM) is applied with the explicit expressions of the J0 count for beam elements under all above support conditions. In return, there is no need to refine the element in the DSM, and thus, it becomes immensely efficient. The accuracy and efficiency of the proposed methodology are extensively assessed for different solid beams, thin-walled structures and reinforced panels and the results are compared with those appearing in published literature and also checked by 3D finite element (FE) solutions.本文提出了一种仅使用位移变量的高阶理论的精确动态刚度公式,并随后用于研究实心梁、薄壁结构和加固板结构的自由振动特性。从本质上讲,高阶位移场是通过使用卡雷拉统一公式(CUF)以及使用双线性、三次方和四阶拉格朗日多项式对横截面运动学进行离散化而形成的。特别是采用了基于拉格朗日展开的分量法(CW),将实心部分和薄壁部分视为两个可组装的独立分量。虚拟位移原理用于推导控制微分方程和相关的自然边界条件。然后,通过将谐波变化载荷的振幅与响应的振幅联系起来,得出精确的动态刚度矩阵。动态刚度矩阵的显式项也一并列出。动态刚度法(DSM)的 Wittrick-Williams 算法与上述所有支撑条件下梁元素的 J0 数值的明确表达式一起应用。反过来,在 DSM 中不需要对元素进行细化,因此变得非常高效。针对不同的实心梁、薄壁结构和加固板,对所建议方法的准确性和效率进行了广泛评估,并将结果与已发表文献中的结果进行了比较,同时还通过三维有限元 (FE) 解决方案进行了检验。Mechanical response of a novel square dome shell with bistable behavior: improved analytical method and empirical modelZhuangzhuang Li, Xuelin Li, Zhuoyu Guo, Yue Zhou, Jiahui Lin, Zonglai Mo, Jun Lidoi:10.1016/j.tws.2024.111722具有双稳态行为的新型方形穹顶壳的机械响应:改进的分析方法和经验模型In this study, a novel square dome-shaped shell with a fascinating bistable behavior is proposed, which is able to quickly switch to a new stable configuration within its elastic range under a certain load, due to its elastic instability. Compared to most circular shells currently studied, it is easier to arrange multiple structures in three-dimensional space to obtain multistable responses. Numerical and experimental methods were adopted for the study of the mechanical response of the square shell, and main influence parameters were also investigated. In addition, an improved piecewise fitting method is introduced to establish an empirical formula for predicting the mechanical response of bistable shells, which can be used to guide the design of bistable shells. Finally, two types of metamaterials, uniaxial compressible metamaterials and triaxial compressible metamaterials, are successfully designed according to the above theory, the typical behaviors of which are studied via simulations. This novel structure presented in this paper has broad application prospects in the fields of energy absorption and programmable deformation structures.本研究提出了一种具有迷人双稳态行为的新型方形穹顶壳,由于其弹性不稳定性,在一定载荷作用下,能够在弹性范围内快速切换到新的稳定构型。与目前研究的大多数圆壳相比,它更容易在三维空间中排列多个结构,从而获得多稳响应。采用数值和实验方法研究了方壳的力学响应,并对主要影响参数进行了研究。此外,还引入了一种改进的分片拟合方法,建立了预测双稳态壳力学响应的经验公式,可用于指导双稳态壳的设计。最后,根据上述理论成功设计了两种超材料,即单轴可压缩超材料和三轴可压缩超材料,并通过仿真研究了其典型行为。本文介绍的这种新型结构在能量吸收和可编程变形结构领域具有广阔的应用前景。Design of Cold-Formed Z-shaped purlin-to-rafter connections subject to pull-through failureHaripriya Karthikeyan, Bishal Naik, Mahendrakumar Madhavandoi:10.1016/j.tws.2024.111725 受拉穿失效影响的冷成型 Z 形檩条与椽子连接设计The current study is focused on understanding the pull-through behaviour of Z-Shaped Cold-Formed Steel (CFS) purlin-to-rafter connection. A total of forty tests were conducted using small-scale testing methods to investigate the influence of parameters such as thickness, depth, and flange width of the purlin section along with the size of the screw head diameter. The results indicated that the test specimens exhibited two modes of pull-through failure (i) rupture-type failure and (ii) bearing-type failure. A transition from rupture-type to bearing-type was observed with an increase in thickness from 1 mm to 3 mm. Both the failure modes were accompanied by tilting of the screw due to eccentricity in the applied load for Z-Shaped purlins. A full-field measurement approach called Three-Dimensional Digital Image Correlation (3D-DIC) technique was employed to better understand the failure mechanism. The DIC strain contours adequately captured the tilting of the screw that can be attributed to the increased strain and out-of-plane deformation at the vicinity of the screw head. A comparison of the test with existing design standards indicates that the design guidelines are unconservative for Z-shaped purlin sections. A modified design equation is proposed to determine the pull-through capacity of Z-shaped purlin-to-rafter connection. Further, reliability study was carried out to determine the resistance and safety factors for the preliminary design equations proposed.当前研究的重点是了解 Z 形冷弯型钢(CFS)檩条与椽子连接的拉穿行为。研究人员使用小规模测试方法进行了总共 40 次测试,以研究檩条截面的厚度、深度和翼缘板宽度等参数以及螺钉头直径大小的影响。结果表明,试样表现出两种拉穿失效模式(i)断裂型失效和(ii)承载型失效。随着厚度从 1 毫米增加到 3 毫米,可观察到从断裂型向轴承型的过渡。对于 Z 形檩条来说,这两种失效模式都伴随着螺杆因外加载荷偏心而倾斜。为了更好地了解失效机理,我们采用了一种名为三维数字图像相关(3D-DIC)技术的全场测量方法。DIC 应变轮廓图充分捕捉到了螺杆的倾斜,这可归因于螺杆头部附近的应变增加和平面外变形。将测试结果与现有设计标准进行比较后发现,对于 Z 形檩条截面而言,设计准则并不严谨。我们提出了一个修改后的设计方程,以确定 Z 型檩条与椽子连接的抗拉能力。此外,还进行了可靠性研究,以确定初步设计方程的阻力和安全系数。A two-direction cross-iteration solution for in-plane vibrations of thin-walled composite plates with a simplified explicit vibration mechanical modelLin Zhao, Yuan Liu, Xibin Cao, Zhongxi Shao, Xuan Zhang, Qingyang Deng, Chenhao Sundoi:10.1016/j.tws.2024.111728用简化的显式振动力学模型解决薄壁复合板平面内振动的双向交叉迭代问题For the fine and high reliability design of advanced precision engineering structures, this work presents an analytically cross-iteration method for in-plane vibrations analysis of thin-walled composite plates, the single-layer and laminated structures both involved. The governing equations and corresponding boundary conditions are derived adopting Rayleigh’s principle, in which the governing partial differential equations are transferred into ordinary differential equations. The most important advantage of this method lies in the fact that the explicit eigenvalue equations and mode functions are obtained with only a series of four-by-four matrices by simplifying boundary conditions in the two-direction cross-iteration procedures. Accuracy of the present method is verified by comparison with the previous studies and the finite element method in natural characteristics solutions, and convergence analysis on the single-layer orthotropic plates and composite laminates reveals the high efficiency and stability. Finally, the effects of boundary conditions, ply orientation angles, stacking sequences, aspect ratios and stiffness ratios on the in-plane natural characteristics are investigated. The extensive results presented in this work for the first time can be taken as the benchmarks data compared with other methods.为实现先进精密工程结构的精细化和高可靠性设计,本研究提出了一种分析交叉迭代法,用于薄壁复合材料板的面内振动分析,包括单层结构和层状结构。利用雷利原理推导出控制方程和相应的边界条件,并将控制偏微分方程转换为常微分方程。该方法最重要的优点在于,通过简化双向交叉迭代程序中的边界条件,只需一系列四乘四矩阵即可获得显式特征值方程和模态函数。通过与前人的研究和自然特性求解中的有限元法进行比较,验证了本方法的准确性,对单层正交板和复合层压板的收敛分析表明了本方法的高效性和稳定性。最后,研究了边界条件、层间取向角、堆叠顺序、纵横比和刚度比对平面内自然特性的影响。本研究首次提出的大量结果可作为与其他方法比较的基准数据。Experimental and numerical investigations of damage and ballistic limit velocity of CFRP laminates subject to harpoon impactWei Zhao, Zhaojun Pang, Mingxiao Wang, Peng Li, Zhonghua Dudoi:10.1016/j.tws.2024.111732受鱼叉撞击的 CFRP 层压板损伤和弹道极限速度的实验和数值研究The harpoon is a space debris capture mechanism with strong adaptability to targets. In this paper, experiments and finite element models are used to study the harpoon impact on carbon fiber laminate. Firstly, a harpoon penetration gas gun experiment was designed to obtain the damage and ballistic limit velocity of carbon fiber laminates. Then finite element modeling and numerical simulation of the impact on the laminate were carried out using the user-defined VUMAT subroutine in ABAQUS, focusing on the ballistic limit velocity change, damage evolution of the laminate and energy absorption of the laminate when the harpoon penetrates the laminate obliquely at a specific angle. The results showed that compared with vertical penetration, the ballistic limit velocity of harpoon increased by 3.2%, 9.6% and 24.3% respectively under 15°, 30° and 45° oblique penetration conditions; and with the increase of harpoon impact angle, the damage of laminates gradually tended to occur on one side of the projection of harpoon on laminates; while in terms of energy absorption, the energy absorption of laminates for the same angle tended to a constant value as the launch velocity increased.鱼叉是一种空间碎片捕获装置,对目标具有很强的适应性。本文利用实验和有限元模型研究了鱼叉对碳纤维层压板的影响。首先,设计了鱼叉穿透气 枪实验,以获得碳纤维层压板的损伤和弹道极限速度。然后使用 ABAQUS 中用户自定义的 VUMAT 子程序对层压板的冲击进行有限元建模和数值模拟,重点研究了鱼叉以特定角度斜穿透层压板时,层压板的弹道极限速度变化、损伤演化和能量吸收。结果表明,与垂直穿透相比,在 15°、30° 和 45°斜穿透条件下,鱼叉的弹道极限速度分别增加了 3.2%、9.6% 和 24.3%;随着鱼叉撞击角度的增加,层压板的损伤逐渐趋向于鱼叉在层压板上投影的一侧;而在能量吸收方面,随着发射速度的增加,相同角度下层压板的能量吸收趋向于恒定值。Multi-objective optimization design of a new non-uniform rectangular honeycomb sandwich panelXuanhe Luo, Gang Li, Zeng Mengdoi:10.1016/j.tws.2024.111729新型非均匀矩形蜂窝夹芯板的多目标优化设计Honeycomb sandwich panels have a wide range of applications in aerospace, marine and energy industry due to their high stiffness-to-weight ratio. In this study, a new non-uniform rectangular honeycomb core is presented to promote its material utilization ratio. The non-uniform wall of honeycomb core is described using Bezier curves, and the effective elastic constants are obtained by both the geometric equivalent method and the strain energy-based homogenization method. To analyze the bending and buckling behaviors of the sandwich panel, the parabolic shear deformation theory is adopted, and the governing equations are derived by employing Hamilton's principle. Then, the closed-form solutions of bending and buckling responses of the non-uniform rectangular honeycomb sandwich panel are derived. Furthermore, multi-objective design formulations are established, with the objectives of minimizing the weight and deflection, and maximizing the critical buckling load. Illustrative examples demonstrate that the non-uniform design of the honeycomb core can remarkably increase the material utilization rate and improve the mechanical performance of sandwich panels.蜂窝夹芯板具有很高的刚重比,因此在航空航天、航海和能源行业有着广泛的应用。本研究提出了一种新型非均匀矩形蜂窝芯,以提高其材料利用率。利用贝塞尔曲线描述了蜂窝芯的非均匀壁,并通过几何等效法和基于应变能的均质化法获得了有效弹性常数。为了分析夹芯板的弯曲和屈曲行为,采用了抛物线剪切变形理论,并利用汉密尔顿原理推导了控制方程。然后,推导出了非均匀矩形蜂窝夹芯板弯曲和屈曲响应的闭式解。此外,还建立了以重量和挠度最小化以及临界屈曲载荷最大化为目标的多目标设计公式。示例表明,蜂窝芯的非均匀设计可显著提高材料利用率,改善夹芯板的机械性能。A comparative study on failure mechanisms of open-hole and filled-hole composite laminates: Experiment and numerical simulationDi Zhang, Jin Zhou, Jizhen Wang, Wenxin Zhang, Zhongwei Guandoi:10.1016/j.tws.2024.111730关于开孔和填充孔复合材料层压板失效机理的比较研究:实验与数值模拟The strength of composites with open holes (OH) and filled holes (FH) is a critical factor in determining mechanical allowances for engineering design. This study employs both experimental and numerical analyses to investigate the mechanical behaviour of composite laminates subjected to open-hole tension (OHT) and open-hole compression (OHC), filled-hole tension (FHT) and filled-hole compression (FHC). A progressive damage model (PDM) has been developed to predict the load-carrying capacity of both OH and FH laminates, with deviations lower than 6 % in comparison to the corresponding experimental results. Results indicate that OHC/FHC laminates experience more pronounced damage compared to OHT/FHT laminates prior to the maximum load. Additionally, delamination in FHC laminates is significantly reduced compared to OHC laminates. In comparison to OHT/OHC laminates, the presence of a filled bolt increases the maximum load of FHT/FHC laminates by 10.8 % and 36.0 %, respectively, due to relieving the stress concentration near the hole. Moreover, a higher contact friction coefficient between the bolt and laminate leads to a higher maximum load, particularly for FHC laminates, as the increased friction effectively hinders the matrix crack propagation. These findings provide valuable insights for assisting the design of composite structures.带有开孔(OH)和填充孔(FH)的复合材料的强度是确定工程设计机械余量的关键因素。本研究通过实验和数值分析来研究复合材料层压板在受到开孔拉伸(OHT)和开孔压缩(OHC)、填充孔拉伸(FHT)和填充孔压缩(FHC)作用时的机械性能。建立的渐进损伤模型(PDM)可预测 OHC 和 FHC 复合材料的承载能力,与相应的实验结果相比,偏差小于 6%。结果表明,与 OHT/FHT 层压板相比,OHC/FHC 层压板在最大载荷之前经历了更明显的损坏。此外,与 OHC 层压板相比,FHC 层压板的分层现象明显减少。与 OHT/OHC 层压板相比,填充螺栓的存在使 FHT/FHC 层压板的最大载荷分别增加了 10.8% 和 36.0%,这是由于孔附近的应力集中得到了缓解。此外,螺栓与层压板之间的接触摩擦系数越大,最大载荷就越大,尤其是对于 FHC 层压板,因为摩擦力的增加会有效阻碍基体裂纹的扩展。这些发现为复合材料结构的设计提供了宝贵的启示。The competition between buckling and stress failure of degraded composite cylindrical shell under combined axial compression and external pressure loadsW.M. Mahdy, Linjuan Wang, Fengrui Liu, Libin Zhaodoi:10.1016/j.tws.2024.111731轴向压缩和外部压力联合载荷下降解复合材料圆柱壳体屈曲与应力破坏之间的竞争When thin-walled composite cylindrical shells are subjected to combined loads, not only will they buckle, but they could fail under overstressing. Buckling-failure and stress-failure are two types of failure that compete mutually, and if one of them occurs, the structure loses its ability to carry the load. However, there is a lack of study, and very little attention was paid to the competitive-failure of the composite cylindrical shells under combined loads. To bridge this research gap, a competitive failure analysis framework of degraded composite cylindrical shells exposed to combined axial compression and external pressure loads was developed, considering the nonlinear buckling-failure interacting curve approach for buckling-failure analysis and the Tsai-Wu failure criterion for stress-failure analysis. The material degradation model was adopted to modify the properties of the failed ply based on two degrading philosophies. The proposed framework agrees well with the published results. Extensive parametric studies are accomplished and presented to detect the failure mode of composites. For material parametric study, the variation of material properties does not significantly affect the shape of the normalized buckling-failure interacting curve, while it appreciably affects the behavior of the stress-failure interacting curve. Moreover, it is found that as the proportions of the longitudinal compressive strength to longitudinal modulus and transverse tensile strength to transverse modulus of composite materials increase, the tendency for buckling-failure increases; otherwise, stress-failure happens. For a geometric parametric study, decreasing the radius-to-thickness ratio leads to an increase in the shape of the buckling-failure interacting curve and the possibility of stress-failure.当薄壁复合材料圆柱形壳体承受联合载荷时,不仅会发生屈曲,而且可能在过应力作用下失效。屈曲失效和应力失效是两种相互竞争的失效类型,如果其中一种失效发生,结构就会丧失承载能力。然而,目前对复合材料圆柱形壳体在组合载荷作用下的竞争失效还缺乏研究,关注度也很低。为了弥补这一研究空白,我们建立了承受轴向压缩和外部压力联合载荷的降解复合材料圆柱壳竞争失效分析框架,在屈曲失效分析中考虑了非线性屈曲失效交互曲线方法,在应力失效分析中考虑了蔡武失效准则。根据两种降解原理,采用材料降解模型来修改失效层的属性。所提出的框架与已公布的结果非常吻合。为检测复合材料的失效模式,完成并介绍了广泛的参数研究。在材料参数研究方面,材料特性的变化对归一化屈曲-失效交互曲线的形状没有显著影响,但对应力-失效交互曲线的行为有明显影响。此外,研究还发现,当复合材料的纵向抗压强度与纵向模量、横向抗拉强度与横向模量的比例增加时,屈曲失效的趋势也会增加;反之,则会发生应力失效。在几何参数研究中,减小半径与厚度之比会导致屈曲-失效交互曲线的形状和应力-失效的可能性增加。来源:复合材料力学仿真Composites FEM

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