【新文速递】2024年12月31日复合材料SCI期刊最新文章

今日更新：Journal of the Mechanics and Physics of Solids 1 篇，Thin-Walled Structures 2 篇Journal of the Mechanics and Physics of SolidsDeciphering necking in granular materials: Micromechanical insights into sand behavior during cycles of triaxial compression and extensionJunhe Cui, Konstantinos Karapiperis, Øyvind Torgersrud, Edward Andò, Gioacchino Viggiani, Jose Andradedoi:10.1016/j.jmps.2024.106022解读颗粒材料中的颈缩：在三轴压缩和拉伸周期中对砂土行为的微观力学见解This study elucidates the fundamental governing mechanisms behind necking instability in granular materials, a phenomenon extensively documented in the literature yet lacking a clear explanation of its underlying causes. Our findings suggest that the phenomenon of tensile necking instability can be understood through the framework of anisotropic critical state theory, considering both local porosity and fabric anisotropy. To unravel these mechanisms, we construct a digital twin, using the level-set discrete element method (LS-DEM), of a Hostun sand specimen undergoing alternating cycles of triaxial compression and triaxial extension within an x-ray tomograph. The accuracy of the LS-DEM simulation is substantiated by its replication of the multiscale response observed in experiments, including macroscale stress–strain behavior, evolution of the deviatoric strain field, and notably, initiation and progression of necking during triaxial extension.本研究阐明了颗粒材料颈缩不稳定性背后的基本控制机制，这是一种在文献中广泛记录的现象，但缺乏对其根本原因的明确解释。我们的研究结果表明，拉伸颈失稳现象可以通过考虑局部孔隙率和织物各向异性的各向异性临界状态理论的框架来理解。为了解开这些机制，我们使用水平集离散元法（LS-DEM）构建了一个数字双胞胎，该双胞胎是在x射线断层摄影中经历三轴压缩和三轴拉伸交替循环的Hostun砂标本。LS-DEM模拟的准确性通过复 制实验中观察到的多尺度响应得到证实，包括宏观尺度应力-应变行为，偏应变场的演化，特别是三轴扩展过程中颈缩的开始和发展。Thin-Walled StructuresProbabilistic Fatigue Prognosis of Novel Ring-Flange Connections in Lattice-Tubular Hybrid (LTH) Wind Turbine TowersYuxiao Luo, Dong Zhou, Junlin Heng, Kaoshan Dai, Yangzhao Liu, Keyi Qiudoi:10.1016/j.tws.2025.112908 格管混合（LTH）风力发电塔新型环-法兰连接的概率疲劳预测The increasing size and height of wind turbines demand innovative support structures like the lattice-tubular hybrid (LTH) tower, which enhances material efficiency and harnesses high-speed wind at greater heights. However, the complex dynamics of tall LTH towers, especially in their lattice sections, pose unique fatigue challenges. This study focuses on fatigue deterioration risks in ring-flange connections of a 160m-5MW LTH wind turbine tower, part of China's first large-scale LTH project. A multi-physics simulation, incorporating site-specific wind conditions, was performed to generate fatigue stress spectra for critical flanges. Fatigue tests on high-strength rivets connections were conducted, and probability-stress-life (P-S-N) models for both rivets and bolts were derived. The results show that after 20 years, bolt connections have fatigue reliability indices of 0.96 (individual bolts) and -0.58 (overall flange), both below the critical threshold of 2. In contrast, rivet connections demonstrate significantly higher reliability indices of 6.1 and 12.0, respectively. Additionally, a 60° tower orientation optimizes fatigue reliability. These findings suggest that high-strength rivets offer a promising solution for enhancing fatigue reliability and reducing maintenance demands in LTH towers, providing valuable insights for the wind energy industry.风力涡轮机的尺寸和高度不断增加，需要创新的支撑结构，如格管混合（LTH）塔，以提高材料效率，并在更高的高度利用高速风。然而，高LTH塔的复杂动力学，特别是其晶格部分，带来了独特的疲劳挑战。本研究的重点是160m-5MW LTH风电塔环法兰连接的疲劳恶化风险，这是中国第一个大型LTH项目的一部分。通过多物理场模拟，结合现场特定的风力条件，生成关键法兰的疲劳应力谱。进行了高强度铆钉连接疲劳试验，推导了铆钉和螺栓的概率-应力-寿命（P-S-N）模型。结果表明：20年后，螺栓连接的疲劳可靠度指数（单个螺栓）为0.96,（整体法兰）为-0.58，均低于临界阈值2；相比之下，铆钉连接的可靠性指数分别为6.1和12.0。此外，60°的塔架朝向优化了疲劳可靠性。这些发现表明，高强度铆钉为提高LTH塔的疲劳可靠性和减少维护需求提供了一个有前途的解决方案，为风能行业提供了有价值的见解。Atomistic and finite element modeling of mechanical properties and energy dissipation mechanisms in 3D aerosolization-based Voronoi graphene foamsWeixiang Peng, Hortense Le Ferrand, Patrick Onckdoi:10.1016/j.tws.2024.112897 基于三维雾化的Voronoi石墨烯泡沫的力学性能和能量耗散机制的原子和有限元建模Three-dimensional (3D) graphene materials exhibit significant potential for application due to their multifunctional properties, which merge the intrinsic characteristics of 2D graphene with added porosity and unique 3D structural morphologies. In particular, 3D closed-cellular network graphene demonstrates remarkable stiffness while maintaining super-elasticity, outperforming most previously reported carbon-based foams. However, the mechanical properties and energy dissipation mechanisms of these 3D closed-cellular network structures remain poorly understood. To address this, we propose an innovative approach using computational synthesis to construct 3D Voronoi graphene models. Molecular dynamics (MD) and finite element (FE) simulations were then employed to investigate the mechanical properties and microstructure evolution of these 3D Voronoi structures. The results show that the power indices for Young's modulus, tensile strength, and compressive plateau stress as functions of relative density align closely with the theoretical values for ideal closed-cell foams (1, 1, and 2), indicating that the Voronoi structure exhibits a stretching-dominated deformation behavior. Young's modulus of the experimental 3D closed-cell graphene precisely follows the fitting function of the continuum model, validating the accuracy of our 3D Voronoi structural morphologies and the significance of our simulation work. Cyclic loading simulations were also conducted to assess the energy absorption and recovery capabilities of 3D graphene. The findings suggest that lower relative densities result in reduced energy dissipation due to less damage at cell boundaries and effective stress relief through bending and folding. In contrast, higher relative densities lead to increased energy dissipation due to higher stress concentrations and associated damage. Overall, this study offers insights into the deformation mechanisms and energy absorption characteristics of 3D Voronoi graphene, enhancing our understanding of the performance and potential applications of 3D graphene.三维（3D）石墨烯材料由于其多功能特性而显示出巨大的应用潜力，它融合了二维石墨烯的固有特性，增加了孔隙度和独特的三维结构形态。特别是，3D闭细胞网络石墨烯在保持超弹性的同时表现出卓越的刚度，优于大多数先前报道的碳基泡沫。然而，这些三维闭细胞网络结构的力学性能和能量耗散机制仍然知之甚少。为了解决这个问题，我们提出了一种创新的方法，使用计算合成来构建三维Voronoi石墨烯模型。然后采用分子动力学（MD）和有限元（FE）模拟研究了这些三维Voronoi结构的力学性能和微观结构演变。结果表明，杨氏模量、抗拉强度和压缩平台应力的幂指数作为相对密度的函数与理想闭孔泡沫的理论值（1、1和2）非常接近，表明Voronoi结构表现出以拉伸为主的变形行为。实验三维闭孔石墨烯的杨氏模量精确地遵循连续介质模型的拟合函数，验证了我们三维Voronoi结构形态的准确性和我们模拟工作的意义。还进行了循环加载模拟，以评估3D石墨烯的能量吸收和恢复能力。研究结果表明，较低的相对密度可以减少能量耗散，因为细胞边界的损伤较少，并且可以通过弯曲和折叠有效地消除应力。相反，较高的相对密度由于较高的应力集中和相关损伤而导致能量耗散增加。总的来说，这项研究提供了三维Voronoi石墨烯的变形机制和能量吸收特性的见解，增强了我们对三维石墨烯性能和潜在应用的理解。来源：复合材料力学仿真Composites FEM