【新文速递】2025年1月6日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 2 篇，Journal of the Mechanics and Physics of Solids 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 7 篇

International Journal of Solids and Structures

Impact attenuation of sphere on woodpile

Yuran Jin, Qing Peng, Xiaoming Liu

doi:10.1016/j.ijsolstr.2025.113215

球对木桩的冲击衰减

The woodpile structure shows exceptional cushioning and vibration reduction under impact. The impact, such as the case of a sphere impacting on stacked beams (a beam chain), has been studied using the discrete element method (DEM) in the literature, which shows that the DEM approach is limited to low-frequency vibrations, mostly up to the third harmonic mode triggered by the impact. However, many impact contacts, similar to step loads, will induce high-order modal vibrations (excited eigenmodes beyond the fifth modes). Present work encompasses the higher vibrational modes under such impact. With Timoshenko beams considering shear effect, the dynamics of sphere-woodpile impact is studied by coupling the superposition method for higher modes and the Hertz law for nonlinear contact. Result reveals the high mode vibration greatly reduces the contact force on the stacked beam, thus slender beam can expedite the dissipation of impact energy. Also, the higher-order vibrations enhance the speed of wave propagating within the beam chain and amplify attenuation effects. These insights offer a guidance for the design of impact-resistant structures and advanced shock absorbers.

木桩结构在冲击下表现出优异的缓冲和减振性能。文献中已经使用离散元法（DEM）研究了球体撞击堆叠梁（梁链）的情况，结果表明，DEM方法仅限于低频振动，主要是撞击引发的三次谐波模式。然而，许多冲击接触，类似于阶跃载荷，将诱发高阶模态振动（激振特征模态超过第五阶模态）。目前的工作包括在这种冲击下的更高振动模式。考虑剪切效应的Timoshenko梁，采用高模态叠加法和非线性接触的Hertz定律耦合研究了球桩碰撞动力学。结果表明，高模态振动大大降低了叠合梁上的接触力，从而使细长梁加速了冲击能的耗散。此外，高阶振动提高了波在波束链内的传播速度，放大了衰减效应。这些见解为抗冲击结构和先进减震器的设计提供了指导。

Exploring the elliptic fissure cracking mechanisms from the perspective of sand 3D printing technology and Meshfree numerical strategy

Shuyang Yu, Xueying Hu, Zilin Liang

doi:10.1016/j.ijsolstr.2025.113216

从砂土3D打印技术和无网格数值策略的角度探讨椭圆裂纹的开裂机理

The existences of cracks affect the strength and fracture morphologies of rock masses. However, there are few discussions on factors such as fissure apertures and quantities. Based on this background, sand 3D printing is used to prepare rock-like samples. Crack propagation experiments are carried out on fissured samples with different fissure apertures and fissure numbers. DIC technology is utilized to obtain the full-field strain distributions on specimen surfaces. Meanwhile, a meshless numerical method is developed to simulate rock damage evolutions. Results show that: Three crack types can be seen, wing cracks, shear cracks as well as main cracks. Wing crack extensions on two prefabricated fissures outer sides are along the loading direction, while inner side wing cracks overlap with two prefabricated fissures to form a “fusiformis-shaped part”. The propagation of shear cracks after wing cracks indicates final specimen failure. Main cracks exist in the circumstances with large fissure apertures. As fissure apertures increase, wing cracks initiating points deviate from tips, and the appearance of inner wing cracks in double fissure specimens precedes outer wing cracks. Stress–strain curves of the specimen experience five stages: 1) compressive stage; 2) elastic stage; 3) stress drop stage; 4) crack propagation stage and 5) failure stage. Finally, formation mechanisms of wing cracks, shear cracks, “fusiformis-shaped parts” as well as the mechanical influences of fissure apertures on the specimens are discussed.

裂隙的存在影响着岩体的强度和破裂形态。然而，对裂缝的孔径和数量等因素的讨论却很少。基于这一背景，砂石3D打印被用于制备类岩石样品。对不同裂纹孔径和裂纹数的裂纹试样进行了裂纹扩展试验。利用DIC技术获得了试样表面的全场应变分布。同时，提出了一种模拟岩石损伤演化的无网格数值方法。结果表明：裂纹主要有翼形裂纹、剪切裂纹和主裂纹三种类型。两个预制裂缝外侧翼裂纹沿加载方向扩展，内侧翼裂纹与两个预制裂缝重叠，形成“梭形部分”。机翼裂纹后剪切裂纹的扩展表明试样最终破坏。主裂缝存在于裂隙大的情况下。随着裂纹开度的增大，机翼裂纹起始点偏离尖端，双裂纹试样中翼内裂纹先于翼外裂纹出现。试样的应力-应变曲线经历5个阶段：1)压缩阶段；2)弹性阶段；3)应力下降阶段；4)裂纹扩展阶段和5)破坏阶段。最后，讨论了机翼裂纹、剪切裂纹、“梭形部分”的形成机理以及裂纹对试件的力学影响。

Journal of the Mechanics and Physics of Solids

Subsurface microstructure effects on surface resolved slip activity

Jonathan M. Hestroffer, Jean-Charles Stinville, Marie-Agathe Charpagne, Matthew P. Miller, Tresa M. Pollock, Irene J. Beyerlein

doi:10.1016/j.jmps.2024.106023

地下微观结构对地表分解滑动活动的影响

We investigate the influence of subsurface microstructure on the micromechanical and slip activity fields at the free surface on a polycrystalline Ni-based superalloy under deformation. The approach combines full-field crystal plasticity finite element simulations, high resolution three-dimensional electron back-scattered diffraction TriBeam technology, and high-fidelity mirroring of the microstructure to bring to the analysis statistically significant numbers of grains and a broad field of view. The analysis reveals substantial disparities in the spatially resolved fields of stress, lattice rotation, and slip activity at the surface between a columnar grain representation versus the experimental full-3D subsurface representation, with deviations intensifying and changing spatially with applied strain, after slip locally initiates. We show that the location and intensity of incipient slip, as well as choice of primary active slip system, are highly sensitive to the underlying subsurface microstructure. Detailed 3D analysis of exceptionally affected regions identifies that influential subsurface structures are grain boundaries inclined to the surface or near-surface quadruple points. A statistical analysis is conducted to correlate the micromechanical quantities and slip activity to several key microstructure features both on and beneath the surface. The analysis finds that influential subsurface microstructure features are primarily linked to proximity to triple junctions and tendency of free-surface grains to deform via multiple slip systems.

研究了变形条件下多晶镍基高温合金的地下微观组织对自由表面微力学场和滑移活动场的影响。该方法结合了全场晶体塑性有限元模拟、高分辨率三维电子背散射衍射TriBeam技术和高保真微观结构镜像，为分析带来了具有统计学意义的晶粒数量和广阔的视野。分析表明，在局部滑移开始后，柱状晶粒表示与实验的全三维亚表面表示之间，在空间分辨的应力场、晶格旋转和表面滑移活动方面存在显著差异，并且偏差随着施加的应变而加剧和空间变化。研究表明，初期滑动的位置和强度以及主要活动滑动体系的选择对下伏地下微观结构高度敏感。对异常受影响区域的详细三维分析表明，受影响的地下结构是倾向于地表或近地表四点的晶界。进行了统计分析，将微观力学量和滑动活动与地表和地下的几个关键微观结构特征联系起来。分析发现，影响地下微观结构的特征主要与接近三重结和自由表面晶粒通过多重滑移系统变形的趋势有关。

Mechanics of Materials

Enhancing robustness in machine-learning-accelerated molecular dynamics: A multi-model nonparametric probabilistic approach

Ariana Quek, Niuchang Ouyang, Hung-Min Lin, Olivier Delaire, Johann Guilleminot

doi:10.1016/j.mechmat.2024.105237

增强机器学习加速分子动力学的鲁棒性： 多模型非参数概率方法

In this work, we present a system-agnostic probabilistic framework to quantify model-form uncertainties in molecular dynamics (MD) simulations based on machine-learned (ML) interatomic potentials. Such uncertainties arise from the design and selection of ML potentials, as well as from training aspects pertaining to the definition of datasets and calibration strategies. Our approach relies on a stochastic reduced-order model (SROM) where the approximation space is expanded through the randomization of the projection basis. The construction of the underlying probability measure is achieved in the context of information theory, by leveraging the existence of multiple model candidates, corresponding to different ML potentials for instance. To assess the effectiveness of the proposed approach, the method is applied to capture model-form uncertainties in a sodium thiophosphate system, relevant to sodium-ion-state batteries. We demonstrate that the SROM accurately encodes model uncertainties from different ML potentials—including a Neuro-Evolution Potential (NEP) and a Moment Tensor Potential (MTP)—and can be used to propagate these uncertainties to macroscopic quantities of interest, such as ionic diffusivity. Additionally, we investigate the impact of augmenting the snapshot matrix with momenta, and of introducing a frequency-based split in the construction of the random projection matrix. Results indicate that including momenta improves the accuracy of the SROM, while frequency splitting enables stabilization around nominal responses during uncertainty propagation. The proposed enhancements contribute to more robust and stable predictions in MD simulations involving ML potentials.

在这项工作中，我们提出了一个系统不可知的概率框架来量化基于机器学习（ML）原子间势的分子动力学（MD）模拟中模型形式的不确定性。这种不确定性来自机器学习电位的设计和选择，以及与数据集定义和校准策略相关的训练方面。我们的方法依赖于随机降阶模型（rom），其中通过投影基的随机化扩展了近似空间。底层概率度量的构建是在信息论的背景下实现的，通过利用多个候选模型的存在，例如对应于不同的ML潜力。为了评估所提出方法的有效性，将该方法应用于捕获与钠离子状态电池相关的硫代磷酸钠系统中的模型形式不确定性。我们证明，rom准确地编码了来自不同ML电位的模型不确定性，包括神经进化电位（NEP）和矩张量电位（MTP），并可用于将这些不确定性传播到感兴趣的宏观量，如离子扩散率。此外，我们还研究了用动量增加快照矩阵的影响，以及在随机投影矩阵的构造中引入基于频率的分裂。结果表明，加入动量可以提高rom的精度，而分频可以在不确定性传播过程中稳定在标称响应附近。提出的增强有助于在涉及ML电位的MD模拟中进行更稳健和稳定的预测。

International Journal of Plasticity

Enhancing the strength and ductility of pure metal via multi-scale and multitype composite heterostructuring

Zhide Li, Cheng Lu, Charlie Kong, M.W. Fu, Hailiang Yu

doi:10.1016/j.ijplas.2025.104241

通过多尺度、多类型复合异质结构提高纯金属的强度和塑性

High strength and good ductility are essential for the engineering applications of structural materials, yet these two attributes often do not coexist. In the present study, a composite heterostructuring designed with multi-scale, lamellar, and bimodal was developed to deal with the trade-off between strength and ductility. This heterostructuring includes coarse-grain soft domains arranged in a lamellar structure within a matrix characterized by both fine and ultrafine grains arranged in a bimodal structure created through a straightforward thermo-mechanical process. The gradient in strength among various grain structures generates a gradient in strain during deformation. This promotes the generation of additional geometrically necessary dislocations (GNDs) in the soft domain, favouring strength enhancement. The ongoing and efficient accumulation and evolution of GNDs within the soft domains are further developed into the dislocation cells and subgrain boundaries, which, on the other hand, increase the strain hardening and, hence, the ductility.

高强度和良好的延展性是结构材料在工程上应用的必要条件，但这两种特性往往不能同时存在。在本研究中，开发了一种具有多尺度、片层和双峰的复合异质结构，以处理强度和延性之间的权衡。这种异质结构包括在基体中以层状结构排列的粗晶软畴，其特征是细晶粒和超细晶粒排列在通过直接的热机械过程产生的双峰结构中。不同晶粒结构之间的强度梯度在变形过程中产生应变梯度。这促进了在软畴中产生额外的几何必要位错（GNDs），有利于强度增强。在软畴内，GNDs持续有效的积累和演化进一步发展为位错胞和亚晶界，这一方面增加了应变硬化，从而提高了塑性。

Thin-Walled Structures

Symmetric deformation of functionally graded annular structures with arbitrarily varying material properties: operator discrete approximation for variable coefficient ordinary differential equation model

Pengpeng Shi, Jun Xie, Hui Li, Xing Li

doi:10.1016/j.tws.2025.112911

具有任意变化材料性质的功能梯度环形结构的对称变形：变系数常微分方程模型的算子离散逼近

The mechanical analysis of functionally graded materials (FGMs) annular structures, which is crucial for structural safety, presents challenges due to the arbitrarily varying material properties. However, most current studies analyze the mechanical behavior of FGMs annular structures based on some given property profile gradient models, which is insufficient to support effective mechanical analysis on the structure deformation with arbitrarily varying material properties. This paper focuses on the mechanical problems (static response, rotating effect, and magnetic field effect) in the FGMs annular structures with arbitrary elastic properties. This paper proposes the Operator Discrete Approximation (ODA) method to solve the deformation problem of FGMs annular structures. The validity and accuracy of the ODA method are verified by comparison with existing analytical solutions or finite difference numerical solutions. And the effectiveness of the ODA method for three types of FGMs problems is discussed in detail. Then, many numerical examples of structures analysis are discussed for FGMs cylinder and spherical shell in detail, involving cylinder and sphere structures, ten property profiles gradient models and dozens of volume fraction gradient models (three volume fractions gradation and five homogenization schemes). The results show that the ODA method can effectively addresses stress discontinuities and overcomes the oscillation problem of circumferential stress in traditional multilayer heterogeneous structures methods. This research presents an alternative approach to addressing the mechanical challenges associated with FGMs annular structures, particularly those with arbitrarily varying material properties.

功能梯度材料（fgm）环形结构的力学分析对结构安全至关重要，但由于材料性能的任意变化，给其力学分析带来了挑战。然而，目前的研究大多是基于一些给定的性能曲线梯度模型来分析fgm环形结构的力学行为，这不足以支持对任意变化材料性能的结构变形进行有效的力学分析。本文主要研究了具有任意弹性特性的fgm环形结构的静响应、旋转效应和磁场效应等力学问题。本文提出了算子离散逼近（ODA）方法来求解fgm环形结构的变形问题。通过与已有解析解或有限差分数值解的比较，验证了ODA方法的有效性和准确性。并详细讨论了ODA方法在三类女性生殖器切割问题中的有效性。然后，详细讨论了fgm圆柱和球壳结构分析的许多数值实例，包括圆柱和球结构、10种性能曲线梯度模型和数十种体积分数梯度模型（3种体积分数梯度和5种均质化方案）。结果表明，ODA方法能有效地解决应力不连续问题，克服了传统多层非均质结构方法的周向应力振荡问题。这项研究提出了一种替代方法来解决与fgm环形结构相关的机械挑战，特别是那些具有任意变化材料性能的结构。

Plastic buckling and wrinkling behavior of tubes under combined bending and torsion loads

Hui Wang, Jianjun Wu, Yaochen Lin, Wei Wu, Mengyuan Wang, Zekun Yang, Long Liu

doi:10.1016/j.tws.2025.112912

弯扭复合载荷下管材的塑性屈曲和起皱行为

Bending and torsion processes are commonly used for the forming of spatial tubes. However, buckling and wrinkling pose a significant challenge to the high-quality and stable forming of spatial tubes. To reveal the interaction mechanism of bending-torsion buckling (BTB) during the forming process, a quadratic model of BTB under plastic buckling instability was proposed. According to the buckling phenomena of simulation and experiment, the BTB state was divided into three zones, namely Zone I (torsion-dominated zone), Zone II (bending-torsion transition zone), and Zone III (bending-dominated zone). The characteristics of bending-torsion response changes, buckling wrinkle features, and critical load variation in the three zones were studied. Considering the complex interaction of bending and torsional buckling, an analytical method for the critical load of tubes under combined bending-torsion action has been provided. This method is based on the energy approach, incorporating pure bending and pure torsion buckling, along with the quadratic model of BTB. The effectiveness of the proposed theoretical model was verified by finite element (FE) simulation, and the influence of tube geometric characteristics, material parameters, and initial imperfection amplitude on the BTB interaction was discussed.

弯曲和扭转工艺通常用于空间管的成形。然而，屈曲和起皱对空间管的高质量和稳定成形提出了重大挑战。为了揭示成形过程中弯曲-扭转屈曲（BTB）的相互作用机理，建立了塑性屈曲失稳条件下弯曲-扭转屈曲的二次模型。根据模拟和实验的屈曲现象，将BTB状态划分为3个区域，即I区（扭转主导区）、II区（弯曲-扭转过渡区）和III区（弯曲主导区）。研究了三个区域的弯扭响应变化特征、屈曲起皱特征和临界载荷变化特征。考虑弯扭复合屈曲的复杂相互作用，提出了一种弯扭复合作用下钢管临界载荷的分析方法。该方法以能量法为基础，结合了纯弯曲屈曲和纯扭转屈曲，并建立了BTB的二次模型。通过有限元仿真验证了理论模型的有效性，并讨论了管的几何特性、材料参数和初始缺陷幅值对BTB相互作用的影响。

Diminishing potential well barrier in bi-stable energy harvesters by introducing symmetric stiffness

Li Zhao, Ying Gong, Fan Shen, Yan Peng, Shaorong Xie, Zhongjie Li

doi:10.1016/j.tws.2024.112880

引入对称刚度减小双稳态能量采集器的势阱势垒

To diminish the potential well barrier in bi-stable energy harvesters, a three-degree-of-freedom mono-stable energy harvester consisting of a main beam and two symmetrical side beams coupled through magnetic fields is proposed. This article introduces symmetric stiffness for the first time to reduce the potential well barrier of the main beam, preventing potential barriers from hindering the vibration of the main beam. Due to the introduction of side beams, the system can integrate more power generation units, rather than just piezoelectric units attached to the main beam. The distributed parameter model and the electromechanical coupling equations were constructed based on Hamilton's principle and the Galerkin method. Based on the developed model, the static and dynamic mechanical properties of the traditional bi-stable energy harvester (BEH) and the proposed energy harvester were compared. The proposed structure has lower static potential energy and greater dynamic response than that of the BEH. An experimental prototype was designed, and the accuracy of the established model was verified through frequency sweep experiments. The effects of excitation acceleration, lateral and longitudinal magnet gap on the open-circuit voltage of the three power generation units (PGUs) were studied. Meanwhile, impedance matching experiments were carried out. At a lateral gap of 20 mm and a longitudinal gap of 0 mm, the output power of the three PGUs were highest at 6.7 mW, 2.0 mW, and 51.8 mW, respectively. Finally, the three PGUs charged four types of capacitors separately, while the five PGUs were connected in parallel to charge the four types of capacitors under different lateral gaps. This paper provides a new approach to improve the efficiency of vibration energy harvesting in energy collectors under low-intensity excitation conditions.

为了减小双稳态能量采集器中的势阱势垒，提出了一种由一个主梁和两个对称侧梁通过磁场耦合组成的三自由度单稳态能量采集器。本文首次引入对称刚度来减小主梁的势井障，防止势井障阻碍主梁的振动。由于引入了侧梁，该系统可以集成更多的发电单元，而不仅仅是附着在主梁上的压电单元。基于Hamilton原理和伽辽金方法，建立了分布参数模型和机电耦合方程。基于所建立的模型，对传统双稳态能量采集器（BEH）和新型双稳态能量采集器的静态和动态力学性能进行了比较。该结构具有较低的静势能和较大的动力响应。设计了实验样机，并通过扫频实验验证了所建立模型的准确性。研究了励磁加速度、横向和纵向磁隙对三台发电机组开路电压的影响。同时，进行了阻抗匹配实验。当横向间隙为20 mm，纵向间隙为0 mm时，三个pgu的输出功率最高，分别为6.7 mW、2.0 mW和51.8 mW。最后，3个pgu分别对4种电容进行充电，5个pgu并联在不同侧隙下对4种电容进行充电。本文为提高集热器在低强度激励条件下的振动能量收集效率提供了一种新的途径。

A configurable tensegrity-based metastructure with tunable bandgap achieved by structural phase transition

Ao Li, Xu Yin, Ben Guan, Guang-Kui Xu, Li-Yuan Zhang, Xi-Qiao Feng

doi:10.1016/j.tws.2025.112909

通过结构相变实现带隙可调的可配置张拉整体元结构

Metastructures with adjustable bandgaps provide an effective solution for modulating elastic waves and mitigating vibrations in scenarios with variable frequencies. However, achieving simplicity and effectiveness in the tunability of bandgap branches remains a challenge. Here we propose a configurable tensegrity-based metastructure achieved by structural phase transition (i.e., rigidity–flexibility transition of a structure caused by altering its configurational phase) and investigate this novel switching method of tunable bandgaps. The metastructure is composed of multiple well-designed X-tensegrity based structures that permit a reversible rigidity–flexibility transition with continuous unidirectional external loads. It is demonstrated that the present metastructure exhibits rich bandgap characteristics, i.e., tuning elastic wave bandgaps in terms of their ranges and branches. Furthermore, we explore the substantial influence of damping and friction on the dynamic performance of the metastructure. Finally, we experimentally validate the designed metastructure to showcase its vibration attenuation tunability through state switching induced by structural phase transition. The proposed tensegrity-based metastructure holds potential for applications as lightweight devices with the capability of wave attenuation and vibration monitoring.

具有可调带隙的元结构为调制弹性波和减轻频率变化情况下的振动提供了有效的解决方案。然而，实现带隙分支可调性的简单性和有效性仍然是一个挑战。在这里，我们提出了一种可配置的基于张拉整体的元结构，通过结构相变（即由改变其构型相引起的结构的刚性-柔性转变）来实现，并研究了这种可调带隙的新型开关方法。该元结构由多个精心设计的基于x张拉整体的结构组成，允许在连续单向外部载荷下可逆的刚度-柔性过渡。结果表明，该元结构具有丰富的带隙特性，即弹性波带隙在其范围和分支上是可调谐的。此外，我们还探讨了阻尼和摩擦对元结构动力性能的实质性影响。最后，我们通过实验验证了所设计的元结构通过结构相变诱导的状态切换来实现振动衰减的可调性。提出的基于张拉整体结构的元结构具有作为具有波衰减和振动监测能力的轻型设备的应用潜力。

A novel anti-tri-missing rib structure with a central ring for maintaining constant Poisson's ratio under large deformations

Kelan Mo, Fucong Lu, Tinghui Wei, Chuanbiao Zhang, Yi He, Yang Liu, Xiangyu Ling, Yilin Zhu

doi:10.1016/j.tws.2025.112916

一种具有中心环的新型抗三缺失肋结构，可在大变形下保持恒定的泊松比

Auxetic metamaterials, as a novel material, have achieved significant research progress. However, most studies are confined to the small deformation range. Research on auxetic materials under large deformations remains insufficient, and the Poisson's ratio of most auxetic structures changes significantly under large deformations. To address these challenges, this study combines the geometric characteristics of traditional anti-tri-chiral structures (ATC) and anti-tri-missing rib structures (ATMR), proposing a novel anti-tri-missing rib structure with a central ring (CATM). By enhancing the rotational performance of the structure, it can achieve a constant Poisson's ratio under large deformations. Furthermore, this study derived a theoretical expression for the in-plane effective elastic constants of the structure through the application of the energy method. The feasibility of the theoretical formula is verified through experiments and finite element analysis, and the relationship between its mechanical properties and geometric parameters is further discussed. By comparing the analysis results, the study shows that by altering the geometric parameters of CATM, it can achieve a tunable Poisson's ratio, both positive and negative, and maintain a constant Poisson's ratio under large deformations. Under specific parameter conditions, the limit strain for maintaining a constant Poisson's ratio can reach nearly 100%, paving new pathways for the future development of auxetic structures.

增塑型超材料作为一种新型材料，近年来取得了重要的研究进展。然而，大多数研究都局限于小变形范围。对大变形条件下的失活材料的研究还不够充分，大多数失活结构的泊松比在大变形条件下变化明显。为了解决这些挑战，本研究结合了传统的反三手性结构（ATC）和反三缺失肋骨结构（ATMR）的几何特征，提出了一种具有中心环的新型反三缺失肋骨结构（CATM）。通过提高结构的转动性能，可以在大变形下实现恒定的泊松比。此外，本文还应用能量法推导了结构面内有效弹性常数的理论表达式。通过实验和有限元分析验证了理论公式的可行性，并进一步讨论了其力学性能与几何参数之间的关系。通过对分析结果的比较，研究表明，通过改变CATM的几何参数，可以实现正、负泊松比的可调，并在大变形下保持恒定的泊松比。在特定的参数条件下，保持泊松比恒定的极限应变可以达到接近100%，为今后结构的发展开辟了新的途径。

Quantitative evaluation of process-induced yarn geometric imperfection effect on mechanical response of plain-woven C/SiC composites: X-ray tomography-based finite element analysis

Zhouyue Gu, Xiaolei Zhu, Xiaofeng Lu, Panding Wang, Hongshuai Lei

doi:10.1016/j.tws.2025.112917

工艺诱导纱线几何缺陷对C/SiC平织复合材料力学响应影响的定量评价：基于x射线层析成像的有限元分析

In this paper, the morphology and distribution of yarn imperfections induced by the fabrication process in C/SiC composites were captured and statistically analyzed by X-ray computed tomography using deep learning methods for image processing. Subsequently, these imperfections were decoupled into four typical characteristic imperfections: fiber cross-sectional shape, under-sized (over-sized) yarn cross-section, yarn cross-section variation, and yarn waviness. High-fidelity image-based finite element method (IB-FEM) model was generated from CT images, which considered the mesoscopic geometric morphology. The tensile response and failure mechanism of the as-designed model, IB-FEM model, and statistical models were established and verified by experimental results. The impact of yarn geometric imperfections on tensile properties was systematically discussed and elucidated. The results indicate that the intensification of yarn geometric imperfections (yarn cross-section variation and yarn waviness) significantly weakened the ultimate bearing capacity and failure strain of composites under tension, which have greater impacts than other geometric imperfections.

本文采用深度学习图像处理方法，利用x射线计算机断层扫描技术捕获了C/SiC复合材料中由制造过程引起的纱线缺陷的形态和分布，并进行了统计分析。随后，将这些缺陷解耦为四种典型的特征缺陷：纤维横截面形状、纱线横截面过细（过细）、纱线横截面变化和纱线波纹度。基于CT图像的高保真图像有限元法（IB-FEM）模型考虑了细观几何形态。建立了设计模型、IB-FEM模型和统计模型的拉伸响应和破坏机理，并通过实验结果进行了验证。系统地讨论和阐明了纱线几何缺陷对拉伸性能的影响。结果表明：纱线几何缺陷（纱线截面变化和纱线波纹度）的增强显著削弱了复合材料的极限承载力和破坏应变，其影响大于其他几何缺陷；

An accurate system-level nonlinear order-reduction for the flexible solar array system using global modes

Tengfei Yuan, Wei Fan, Hui Ren

doi:10.1016/j.tws.2024.112890

基于全局模态的柔性太阳能电池阵系统的精确系统级非线性降阶方法

Dynamic analysis of solar array structures is a challenging job due to their complexity and nonlinearity. In this paper, an accurate and efficient reduced-order model of the solar array system is developed. The reduced model is derived by using the system-level nonlinear reduction strategy, where the global flexible modes and their corresponding modal derivatives are adopted to describe large deformations of the system. The system-level approach is superior to other component-level reduction methods in terms of computational efficiency. For the case of linear constraints, the proposed approach can reduce the high-dimensional differential algebraic equations (DAEs) system to a low-dimensional ordinary differential equations (ODEs) system. The reduced nonlinear elastic forces are polynomials of modal coordinates with constant coefficients, and these coefficients can be evaluated in advance to further improve efficiency. This is convenient for both equation solving and controller design. The nonlinear dynamic responses of the solar array during the orbit modification and attitude maneuver are simulated. The numerical results show that the current system-level reduction method can achieve high efficiency and accuracy in the dynamic analysis of the solar array structures. The present work also provides some guidance for the vibration control and real-time simulation of the flexible spacecraft.

由于太阳能电池阵结构的复杂性和非线性，其动力分析是一项具有挑战性的工作。本文建立了一种准确、高效的太阳能电池阵系统降阶模型。采用系统级非线性约简策略，采用全局柔性模态及其相应的模态导数来描述系统的大变形，推导了系统的约简模型。系统级方法在计算效率方面优于其他组件级约简方法。在线性约束的情况下，该方法可以将高维微分代数方程（DAEs）系统简化为低维常微分方程系统。简化后的非线性弹性力为常系数模态坐标多项式，这些系数可以提前求值，进一步提高效率。这对方程求解和控制器设计都很方便。对太阳阵在轨道修正和姿态机动过程中的非线性动态响应进行了仿真。数值结果表明，现有的系统级约简方法在太阳能电池阵结构动力学分析中具有较高的效率和精度。为柔性航天器的振动控制和实时仿真提供了一定的指导。