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【新文速递】2025年3月26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 3 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇

Composite Structures

Towards detailed oxidation depth and weight loss: A computational and kinetic modeling study of Carbon/Carbon composites oxidation

Fan Zhang, Hongjian Zhang, Shuai Liu, Haitao Cui, Zheyuan Lai

doi:10.1016/j.compstruct.2025.119118

走向详细的氧化深度和重量损失:碳/碳复合材料氧化的计算和动力学建模研究

Carbon/Carbon(C/C) composites are increasingly applied in hot-end components of aero-engines due to superior high-temperature mechanical properties. However, C/C composites are susceptible to oxidation under high-temperature conditions, restricting the application of C/C composites. In this research, a three-dimensional diffusion oxidation kinetic model in the diffusion-controlled oxidation stage was established for C/C composites with an anti-oxidation coating based on mass transfer and diffusion theory. Subsequently, the relationship between oxidation amount and crack oxidation propagation depth with oxidation time was calculated. The oxidation damage of C/C composites in the atmosphere at 700 ℃ ∼900 ℃ was evaluated by weight loss analysis and scanning electron microscopy (SEM) experimentally. Compared with the oxidation kinetic model, the measured values of oxidation weight loss and oxidation depth were in good agreement with the prediction of the model with the maximal error of 7.55 % and 10.87 % respectively, verifying the reliability of the model. Additionally, the sensitivity of oxidation depth to oxidation duration, oxygen partial pressure (OPP) and coating thickness at different temperature are analyzed, aiming to provide a model to predict the oxidation degree and provide reliable recommendations for thermal protection and antioxidant design of C/C composites.

碳/碳(C/C)复合材料由于具有优异的高温力学性能,在航空发动机热端部件中得到越来越多的应用。然而,C/C复合材料在高温条件下容易氧化,限制了C/C复合材料的应用。本研究基于传质扩散理论,建立了含抗氧化涂层的C/C复合材料扩散控制氧化阶段的三维扩散氧化动力学模型。随后,计算了氧化量和裂纹氧化扩展深度随氧化时间的关系。通过失重分析和扫描电镜(SEM)实验评价了C/C复合材料在700 ℃~ 900 ℃大气中的氧化损伤。与氧化动力学模型比较,氧化失重和氧化深度的实测值与模型预测吻合较好,最大误差分别为7.55 %和10.87 %,验证了模型的可靠性。分析了不同温度下氧化深度对氧化持续时间、氧分压(OPP)和涂层厚度的敏感性,旨在建立预测氧化程度的模型,为C/C复合材料的热防护和抗氧化设计提供可靠的建议。


Experimental and numerical study on draping behavior of recycled textile composite reinforcement with different weave patterns

Bo Chen, Bowen Xu, Yang Zhang, Xiaoling Liu

doi:10.1016/j.compstruct.2025.119123

不同织型再生纺织复合材料增强材料悬垂性能的实验与数值研究

This study experimentally and numerically analyzes the draping of recycled fabric with different weave patterns. The recycled fabric was obtained from waste prepregs using a designed microwave thermal process. It is shown that the yarn width and density remain unchanged in the recycling process, but the fiber surface properties are changed, including a decrease in diameter and an increase in roughness. Due to the removal of sizing agents and the fiber diameter decrease, the recycling process also leads to a reduction in fabric thickness and areal density by about 9%. This change significantly modified the mechanical behavior of recycled fabrics compared to virgin fabrics, especially the bending stiffness of recycled fabrics is greatly reduced. Hemisphere and square box forming tests indicated that recycled fabrics tend to wrinkle more than virgin fabrics, and fabrics with a loose structure and less crimp lead to good drapability. A stress resultant shell approach gives simulation results that are in agreement with experiments, particularly the onset of wrinkling. This numerical approach takes into account tensile, in-plane shear, bending and friction behavior of textile reinforcement to reflect the change in fiber properties and weave structures, which proved to have a notable influence on fabric drapability.

本文对不同织型再生织物的悬垂性能进行了实验和数值分析。采用设计的微波加热工艺,从废预浸料中获得再生织物。结果表明,在回收过程中,纱线的宽度和密度保持不变,但纤维的表面性能发生变化,包括直径减小和粗糙度增加。由于施胶剂的去除和纤维直径的减小,回收过程还导致织物厚度和面密度减少约9%。这一变化明显改变了再生织物的力学性能,特别是再生织物的抗弯刚度大大降低。半球和方盒成型试验表明,回收织物比原始织物更容易起皱,结构松散、卷曲少的织物具有良好的垂性。应力产生壳方法给出了与实验一致的模拟结果,特别是起皱的开始。该数值方法考虑了织物增强物的拉伸、面内剪切、弯曲和摩擦行为,以反映纤维性能和组织结构的变化,这些变化对织物的垂降性有显著影响。


Investigation of temperature and structural configuration effects on the mechanical properties of CFRP bolted joints

Xiaodong Liu, Kai Huang, Xiaojian Han, Jindi Zhou, Li Zhang, Licheng Guo

doi:10.1016/j.compstruct.2025.119128

温度和结构形式对CFRP螺栓连接力学性能影响的研究

Composite bolted joints are extensively employed in structural applications and have garnered notable interest in composite component design. This research examined how temperature, hole size, and washer configuration influence the composite bolted joint’s tensile properties, using 3D digital image correlation (DIC) and acoustic emission (AE) methods. The study analyzed load–displacement response, surface strain evolution, damage mode characterization, and damage initiation of joint throughout the tensile testing. The strain and displacement fields of the joint surfaces effectively revealed the competing evolution mechanisms between axial tensile effect and secondary bending effect. The k-means++ clustering algorithm and sentry function were employed to accurately identify damage modes and initiation in the joints. The results indicate that temperature, hole diameter, and washer configuration significantly influence joint strength, with the dominance of axial tensile effects and secondary bending effects varying depending on the load level. Double-sided washers delay damage initiation, while an increase in hole diameter causes damage to initiate earlier. High temperatures significantly delay the initiation of various damage modes.

复合材料螺栓连接广泛应用于结构应用,并引起了复合材料构件设计的关注。本研究采用三维数字图像相关(DIC)和声发射(AE)方法,研究了温度、孔尺寸和垫圈配置对复合螺栓连接拉伸性能的影响。在整个拉伸试验过程中,研究分析了节点的载荷-位移响应、表面应变演化、损伤模式表征和损伤起始。接头表面的应变场和位移场有效地揭示了轴向拉伸效应和二次弯曲效应之间的竞争演化机制。采用k-means++聚类算法和哨兵函数准确识别接头损伤模式和起裂。结果表明,温度、孔直径和垫圈配置对接头强度有显著影响,轴向拉伸效应占主导地位,二次弯曲效应随载荷水平而变化。双面垫圈可以延缓损伤的发生,而增大孔径则会使损伤发生得更早。高温显著延缓了各种损伤模式的发生。


Optimization of preloading process combining elastic interaction and creep relaxation for multi-constraint composite structures

Chang Gao, Yujin Lin, Chenxuan Hu, Haidong Yu

doi:10.1016/j.compstruct.2025.119130

多约束复合材料结构弹性相互作用与蠕变松弛相结合的预压过程优化

The preloading process of composite structure constrained by multiple bolted joints is difficult to be controlled because the elastic interaction between bolts and the creep relaxation of multi-layer viscoelastic structures exist simultaneously. In this paper, an optimization method of preload for multi-constraint composite structure is proposed by combining elastic interaction and long-term load relaxation. The composite structure is equivalent to the viscoelastic multi-layer structure and the load caused by creep relaxation for the multiple bolts is derived based on the viscoelastic constitutive model. The elastic interaction of bolts in relaxation process is considered and the interactive stiffness of multiple bolts is constructed. The iterative algorithm for the preload coupled with creep relaxation and elastic interaction is established. The attenuation behavior of the preload with different initial preloads and sequences for multi-constraint composite structure can be predicted. A data-driven surrogate model for the prediction of preload evolution is established, by which the variation of preload with different preloading processes can be calculated rapidly. Then, the magnitude and uniformity of preload are taken as the optimized objective and the optimal initial preloading parameters are solved, which is useful for the manufacturing of multi-constraint composite structures with long-term storage.

由于螺栓之间的弹性相互作用和多层粘弹性结构的蠕变松弛同时存在,复合结构在多个螺栓连接约束下的预压过程难以控制。本文提出了一种结合弹性相互作用和长期载荷松弛的多约束复合材料结构预紧力优化方法。将复合结构等效为粘弹性多层结构,并基于粘弹性本构模型推导了多螺栓蠕变松弛引起的荷载。考虑锚杆松弛过程中的弹性相互作用,构造了多锚杆的相互作用刚度。建立了考虑蠕变松弛和弹性相互作用的预紧力迭代算法。可以预测多约束复合材料结构在不同初始预紧力和预紧力顺序下的预紧力衰减行为。建立了数据驱动的预紧力演化预测代理模型,可快速计算预紧力随不同预紧过程的变化。然后,以预紧力的大小和均匀性为优化目标,求解了最优初始预紧力参数,为制造具有长期存储能力的多约束复合材料结构提供了理论依据。


Composites Part A: Applied Science and Manufacturing

Stochastic multi-scale modeling for estimating the Mode-I dynamic fracture toughness of CNT-reinforced polymers

Reza Yazdanparast, Roham Rafiee

doi:10.1016/j.compositesa.2025.108882

估计碳纳米管增强聚合物i型动态断裂韧性的随机多尺度模型

A stochastic hierarchical multiscale model is developed to estimate the Mode-I dynamic fracture toughness of CNT-reinforced polymers, capturing both processing-induced inconsistencies and strain rate effects. At the nanoscale, molecular dynamic simulations of CNT pull-out from the matrix are performed to analyze the CNT-polymer interfacial properties at various pull-out speeds. At the microscale, a rate-dependent finite element model is established to characterize the pull-out profiles for different CNT lengths, orientations, and waviness at various pull-out speeds. Then, the CNT bridging phenomenon along the crack growth path is modeled considering viscoelastic-viscoplastic behavior for the matrix. The influence of CNT lengths, waviness patterns, orientations, and volume fractions at the microscale, as well as CNT agglomeration effects at the mesoscale, on critical fracture energy (GID) are determined. At the macroscale, stochastic simulation is performed to estimate GID treating involved uncertainties as random variables. Predicted results are in very good agreement with experimental observations.

建立了一个随机分层多尺度模型来估计碳纳米管增强聚合物的i型动态断裂韧性,同时捕获了加工引起的不一致性和应变率效应。在纳米尺度上,进行了碳纳米管从基体中拔出的分子动力学模拟,分析了碳纳米管聚合物在不同拔出速度下的界面特性。在微观尺度上,建立了一个速率相关的有限元模型来表征不同碳纳米管长度、方向和波浪度在不同拉出速度下的拉出曲线。然后,考虑基体的粘弹-粘塑性行为,建立了碳纳米管沿裂纹扩展路径的桥接现象模型。研究了碳纳米管的长度、波浪形状、取向和体积分数在微观尺度上以及碳纳米管在中尺度上的团聚效应对临界断裂能(GID)的影响。在宏观尺度上,将涉及的不确定性作为随机变量,进行随机模拟来估计GID。预测结果与实验结果非常吻合。


Biaxial bending failure behavior of laminated composite plates under ring-on-ring loading: Effect of layups and interactive terms in failure criteria

Junru Li, Weiyi Kong, Weijie Zhang, Yiding Li, Xuan Zhang, Shibo Yan

doi:10.1016/j.compositesa.2025.108883

环对环加载下层合复合材料板的双轴弯曲破坏行为:层合层的影响和破坏准则中的交互项

This study investigates the biaxial bending failure behavior of laminated composites, through ring-on-ring loading as described by the ASTM C1499 standard, originally developed for isotropic materials. Cross-ply and quasi-isotropic layups of two thicknesses were tested to assess failure mechanism under layup effect. Thin plates exhibited pronounced nonlinear stiffness across different layups while differences diminished in thick laminates. A numerical model employing the recently formulated Fully Rationalized Tsai-Wu failure criterion and further extending the criterion to identify failure modes to facilitate property degradation is developed for failure prediction under multiaxial stress states, aligning well with experimental results without requiring fitting model parameters. The inclusion of interactive terms in the criterion successfully captured multiaxial failure compared to non-interactive ones. Further stress analysis indicates the ASTM C1499 standard is not entirely applicable to laminates regarding equibiaxial flexural strength but highlights its potential for biaxial tensile testing of unidirectional laminates under non-equal stress ratios.

本研究通过ASTM C1499标准所描述的环对环加载来研究层合复合材料的双向弯曲破坏行为,该标准最初是为各向同性材料开发的。对两种厚度的交叉铺层和准各向同性铺层进行了试验,以评估铺层效应下的破坏机制。薄板表现出明显的非线性刚度跨越不同的层压板,而差异减少在厚层压板。采用新近提出的完全合理化的Tsai-Wu破坏准则,并进一步扩展该准则以识别破坏模式以促进性能退化,建立了多轴应力状态下的破坏预测的数值模型,该模型无需拟合模型参数即可与实验结果很好地吻合。与非交互项相比,在准则中包含交互项成功地捕获了多轴破坏。进一步的应力分析表明,ASTM C1499标准并不完全适用于层压板的等双轴弯曲强度,但强调了其在非等应力比下单向层压板的双轴拉伸测试的潜力。


Orthotropic elastic constants and tensile strength of extrusion-based additively manufactured Carbon/Carbon composites after polymer infiltration and pyrolysis

Edwin S. Romero, Bryant Burton, Ashley Hilmas, Eduardo Barocio, Rodney W. Trice

doi:10.1016/j.compositesa.2025.108884

聚合物浸润和热解后增材制造碳/碳复合材料的正交各向异性弹性常数和拉伸强度

This study was aimed at obtaining orthotropic elastic constants and tensile strengths of extrusion-based additively manufactured (EDAM) carbon/carbon (C/C) composites. Micro-computed tomography (µCT) data was coupled with impulse excitation data and Mori-Tanaka homogenization- based microstructural modeling to analyze 50 wt% short carbon fiber-loaded polyphenylene sulfide (PPS)-based C/C composites. After five polymer infiltration and pyrolysis cycles, the elastic constants and average tensile strength were found to be E1 = 30.48 GPa, E2 = 17.85 GPa, E3 = 12.34 GPa, G23 = 5.57 GPa, G13 = 6.65 GPa, G12 = 9.19 GPa, ν23 = 0.28, ν13 = 0.25, ν12 = 0.26, and σT = 12.71 MPa, respectively. The results were unique to the fiber orientation induced during 3D printing and pore volume fraction achieved with densification and highlights the Mori-Tanaka- based microstructural modeling as a beneficial tool for capturing the fiber architecture- and process- dependent behavior of C/C composites.

研究了挤压增材制造(EDAM)碳/碳(C/C)复合材料的正交异性弹性常数和拉伸强度。微计算机断层扫描(µCT)数据与脉冲激励数据和基于Mori-Tanaka均质化的微观结构建模相结合,分析了50 wt%短碳纤维负载聚苯硫醚(PPS)基C/C复合材料。5聚合物渗透和裂解周期后,弹性常数和平均抗拉强度被发现E1 = 30.48的绩点,E2 = 17.85的绩点,E3 = 12.34的绩点,G23 = 5.57的绩点,G13 = 6.65的绩点,G12 = 9.19的绩点,ν23 = 0.28,ν13 = 0.25,ν12 = 0.26,分别和σT = 12.71 MPa。该结果是3D打印过程中诱导的纤维取向和致密化过程中获得的孔隙体积分数的独特结果,并突出了基于Mori-Tanaka的微结构建模是捕获纤维结构和工艺相关行为的有益工具。


Composites Part B: Engineering

Enhanced tensile properties of 3D printed soft-hard composites due to Poisson’s ratio mismatch: Experimental and numerical study

Peijie Sun, Weizhu Yang, Yu Zhang, Baiyu Zhang, Zheming Fan, Lei Li

doi:10.1016/j.compositesb.2025.112413

泊松比失配对3D打印软硬复合材料拉伸性能的影响:实验与数值研究

A novel design of soft-hard integrated composite is proposed by embedding hard lattices with controllable Poisson’s ratio (PR) at large deformation into the soft matrix. Extensive numerical simulations of the hard lattices with controllable PR (HLCPR) and the designed hard lattice reinforced soft matrix (HLRSM) are conducted based on constitutive parameters of the soft and hard materials obtained from standard material tests. PolyJet 3D printing technique is employed to fabricate the studied HLCPR and HLRSM samples with lattice of PR from -0.8 to 0.8, and tensile tests were conducted with the help of DIC method to obtain their mechanical properties and capture the fracture behaviors. Numerical results agree well with the test results in terms of effective Young’s modulus, strength and fracture behaviors. Results show that coupling between the soft matrix and the HLCPR due to deformation mismatch leads to significant enhancement of mechanical properties, and such coupling effect varies with the PR of the HLCPR. The HLCPR of PR -0.8 leads to the strongest coupling effect, while that of PR 0.4 exhibits the weakest. The soft matrix delays fracture initiation in the HLCPR and transforms the fracture mode from sudden rupture to a progressive failure. Results also demonstrate that HLRSM with HLCPR of -0.8 exhibits superior performance compared to that with an uncontrollable PR or breaking hard lattices. A theoretical model was also carried out to further interpret the deformation mismatch induced coupling effect. This study offers helpful guidance for developing high-performance composite materials and structures.

提出了一种将大变形时泊松比可控的硬晶格嵌入软基体的新型软硬集成复合材料设计方法。基于标准材料试验获得的软硬材料本构参数,对具有可控PR的硬晶格(HLCPR)和设计的硬晶格增强软基体(HLRSM)进行了广泛的数值模拟。采用PolyJet 3D打印技术制备了PR为-0.8 ~ 0.8晶格的HLCPR和HLRSM样品,并利用DIC方法进行拉伸试验,获得了其力学性能和断裂行为。数值计算结果与试验结果在有效杨氏模量、强度和断裂行为等方面吻合较好。结果表明:软基体与HLCPR由于变形失配而产生的耦合作用显著增强了HLCPR的力学性能,且这种耦合效应随HLCPR的PR而变化。PR -0.8的HLCPR耦合效果最强,PR 0.4的HLCPR耦合效果最弱。软基质延缓了HLCPR中断裂的发生,将断裂模式从突然断裂转变为渐进式断裂。结果还表明,当HLCPR为-0.8时,HLRSM的性能优于不可控PR或破硬晶格的HLRSM。建立了理论模型,进一步解释了变形失配引起的耦合效应。该研究为高性能复合材料和结构的开发提供了有益的指导。


Composites Science and Technology

Multiscale enhancements in Z-pin reinforcement performance through curing parameters

Jisiyuan Cheng, Yingjie Xu, Weihong Zhang, Weiwei Liu

doi:10.1016/j.compscitech.2025.111157

 

固化参数对z针增强性能的多尺度影响

Z-pinning is employed by composite laminates to enhance interlaminar performances. Z-pinned composites are then cured to obtain a vastly enhanced interlaminar fracture toughness. However, rare research has focused on the curing effects on the mechanical performances of Z-pinned laminates. This paper presents a multiscale experimental and simulation investigation of the curing effects on the individual Z-pin bridging behaviors and the mode Ⅰ interlaminar fracture of multi-pinned laminates by changing holding temperatures and times of cure. The results reveal that a low holding temperature for a long time decreases the cure-induced Z-pin/composite interfacial cracks, thus generating larger Z-pin energy dissipation and a better specimen’s load-carrying capacity. Compared with 403 K for 150 minutes, the Z-pin energy dissipation and interlaminar fracture toughness increased by 32.22 % and 38.82 % by holding at 383 K for 200 minutes. Mesoscale and macroscale models were developed to predict the cure-induced Z-pin interfacial conditions, Z-pin bridging behaviors, and reinforcement efficiency. Combining the experiments and numerical illustration, this paper presents the possibility of optimizing the Z-pinning performances through the curing profiles.

复合材料层合板采用z形钉钉技术来提高层间性能。然后对z -钉接复合材料进行固化,以获得大大增强的层间断裂韧性。然而,关于固化对z -钉合板力学性能影响的研究很少。本文通过多尺度实验和模拟研究了不同保温温度和固化次数对多钉层合板的Z-pin桥接行为和Ⅰ层间断裂模式的影响。结果表明,长时间低温保温可以降低Z-pin/复合材料界面的固化裂纹,从而产生更大的Z-pin能量耗散和更好的试样承载能力。与403 K保温150 min相比,383 K保温200 min后z销的耗能和层间断裂韧性分别提高了32.22%和38.82%。建立了中尺度和宏观模型来预测固化诱导的Z-pin界面条件、Z-pin桥接行为和增强效率。结合实验和数值说明,提出了通过固化型态优化z形钉钉性能的可能性。



 

来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveDeform断裂复合材料非线性航空增材ADS裂纹理论化机材料储能分子动力学多尺度控制纺织螺栓
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【新文速递】2025年3月5日固体力学SCI期刊最新文章

今日更新:Journal of the Mechanics and Physics of Solids 2 篇,Thin-Walled Structures 1 篇Journal of the Mechanics and Physics of SolidsThermo-chemo-mechanical model and variational multiscale framework for material and geometric evolution in frontal polymerizationIgnasius P.A. Wijaya, Philippe Geubelle, Arif Masuddoi:10.1016/j.jmps.2025.106078正面聚合中材料和几何演化的热-化学-力学模型和变分多尺度框架This paper presents a thermodynamically consistent model for thermo-chemo-mechanical processes in frontal polymerization (FP). The model consists of cure kinetics, heat transfer, and finite strain kinematics of nonlinear inelastic solid undergoing finite deformation. The constitutive relations are derived by enforcing non-negative entropy production which implies the existence of cure induced inelastic processes during material property evolution. Rapid curing triggered by thermo-chemical processes results in traveling reaction fronts that traverse the domain, and material properties evolve across these fronts on short time scales, accompanied with chemical expansion/contraction of the constituents. Complexity of the process increases with increased rate of chemical reaction, increased rate of mass transport, and large mechanical deformations. Evolving nonlinearities and coupled thermo-chemo-mechanical effects give rise to spatially localized phenomena that exhibit shear bands, steep gradients, and boundary and/or internal layers. The presence of interfacial effects can also trigger jumps in the fields, leading to further classification as mathematically non-smooth mixed-field problems. These modeling issues require mathematical formulations that can handle rapidly evolving material nonlinearity as well as steep traveling gradients. A stabilized finite element method that is based on the Variational Multiscale (VMS) framework is employed. A unique attribute of the VMS framework is the derivation of the residual-based fine-scale models that represent subgrid scale physics. These models enhance the stability of the numerical method as well as the accuracy of the computed physics. Several test cases are presented that investigate the mathematical attributes of the constitutive model for FP, and the role of enhanced stability and higher spatial accuracy of the proposed stabilized method in free-form printing with evolving polymerization front.本文提出了正面聚合(FP)中热化学机械过程的热力学一致性模型。该模型由非线性非弹性固体在有限变形时的固化动力学、传热和有限应变运动学组成。本构关系是通过强制非负熵产生推导出来的,这意味着在材料性能演化过程中存在固化诱导的非弹性过程。由热化学过程引发的快速固化导致了穿越区域的移动反应前沿,材料性质在短时间尺度上跨越这些前沿演变,伴随着成分的化学膨胀/收缩。过程的复杂性随着化学反应速率的增加、质量传递速率的增加和大的机械变形而增加。不断演变的非线性和耦合的热-化学-机械效应产生了空间局部现象,表现为剪切带、陡峭梯度、边界和/或内层。界面效应的存在也可以触发场的跳跃,导致进一步分类为数学上的非光滑混合场问题。这些建模问题需要能够处理快速发展的材料非线性以及陡峭的行进梯度的数学公式。采用了一种基于变分多尺度框架的稳定有限元方法。VMS框架的一个独特属性是派生了基于残差的细尺度模型,该模型表示子网格尺度物理。这些模型提高了数值计算方法的稳定性和计算结果的准确性。提出了几个测试用例来研究FP本构模型的数学属性,以及所提出的稳定方法在具有进化聚合前沿的自由形状打印中增强稳定性和更高空间精度的作用。Strength and Stiffness of Network Materials with Preferentially Oriented FibersS.N. Amjad, R.C. Picudoi:10.1016/j.jmps.2025.106101优先取向纤维网状材料的强度和刚度Materials made from fibers, referred to here as Network materials, are ubiquitous in biology and engineering. In most practical situations, fibers have preferential orientation in one spatial direction or in a plane. Here we use discrete network models to derive the relationship between the stiffness and strength of networks with pre-aligned fibers and network parameters, including the degree of alignment. Both stiffness and strength can be represented by the product of two functions, one accounting for the effect of alignment and the other representing the effect of network parameters, such as the network density and fiber properties. Failure under multiaxial loading is also considered and it is concluded that failure surfaces in stress space can be collapsed by normalizing the axes with the respective (pre-alignment-dependent) uniaxial strength. This generalizes the structure-properties relation established based on uniaxial tests to the multiaxial case. The inferred scaling laws are compared with a collection of experimental data from the literature obtained with diverse network materials.由纤维制成的材料,在这里被称为网络材料,在生物和工程中无处不在。在大多数实际情况下,纤维在一个空间方向或在一个平面上具有优先取向。在这里,我们使用离散网络模型来推导具有预对准纤维的网络的刚度和强度与网络参数(包括对准程度)之间的关系。刚度和强度都可以用两个函数的乘积来表示,一个函数代表对准的影响,另一个函数代表网络参数的影响,如网络密度和纤维性能。还考虑了多轴载荷下的破坏,并得出结论,应力空间中的破坏面可以通过用各自的(预对准依赖的)单轴强度归一化轴来崩溃。这将基于单轴试验建立的结构-性能关系推广到多轴情况。推导出的标度定律与不同网络材料的文献实验数据进行了比较。Thin-Walled StructuresDynamic frequency analysis of rotating double-layer conical thin shells coupled with semi re-entrant zero Poisson's ratio honeycomb sandwich annular platesLi Yongqiangdoi:10.1016/j.tws.2025.113136半重入零泊松比蜂窝夹层环板耦合双层旋转锥形薄壳的动力频率分析This paper proposes a computational method based on the substructure synthesis approach to analyze the dynamic frequency of rotating double-layer conical thin shells coupled with semi re-entrant (SER) zero Poisson's ratio (ZPR) honeycomb sandwich annular plates (HSAP). The double-layer conical shell is divided into several conical shell substructures according to the position of the annular plate. The dynamic models of the conical shell and annular plate substructures are established based on the Flügge and Donnell-Mushtari thin shell/plate theories, incorporating centrifugal and Coriolis inertia forces. The displacements of the substructures are expressed as a combination of power series and Fourier series. All substructures are assembled using the continuity conditions for eight displacements and four forces at the coupling interfaces of adjacent substructures, and the global free vibration equation of the structure is constructed with the boundary conditions at the ends of the conical shell. The validity of the proposed method is verified through two examples. First, the results obtained using the proposed method are compared with those of the wave based method by converting the conical shell into a cylindrical shell and setting the rotational speed to zero. Second, the calculated dynamic frequencies of the rotating double-layer conical thin shells coupled with SER ZPR HSAP (SZHSAP) are compared with those obtained via the finite element method. Finally, the effects of various boundary conditions, rotational speeds, and geometric parameters of the conical shell and annular plate on the dynamic frequencies of the coupled structure are analyzed.本文提出了一种基于子结构综合方法的双层锥形薄壳与半重入零泊松比蜂窝夹层环板耦合的动态频率计算方法。双层圆锥壳根据环形板的位置分为若干圆锥壳子结构。基于fl<s:2> gge和Donnell-Mushtari薄壳/薄板理论,考虑离心力和科里奥利惯性力,建立了锥形壳和环形板子结构的动力学模型。子结构的位移用幂级数和傅里叶级数的组合表示。采用相邻子结构耦合界面处8个位移和4个力的连续条件对所有子结构进行组合,并以圆锥壳两端的边界条件构建结构的整体自由振动方程。通过两个算例验证了该方法的有效性。首先,将该方法与基于波的方法进行了比较,将锥壳转换为圆柱壳,并设置转速为零。其次,将计算得到的双层锥形薄壳与SER - ZPR - HSAP (SZHSAP)耦合的动态频率与有限元法进行了比较。最后,分析了不同边界条件、转速和圆锥壳-环形板几何参数对耦合结构动力频率的影响。来源:复合材料力学仿真Composites FEM

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