今日更新：International Journal of Solids and Structures 2 篇，Journal of the Mechanics and Physics of Solids 2 篇，Thin-Walled Structures 3 篇International Journal of Solids and StructuresMoiré boundary dominated twisting graphene friction: Scaling laws and geometrical controlKejing Wang, Ao Chen, Jianzhang Huang, Yajiu Zhang, Yingjing Liang, Qiang Handoi:10.1016/j.ijsolstr.2026.114061涡流边界主导的扭转石墨烯摩擦：标度规律和几何控制Twisted bilayer graphene Moiré superlattices offer unique geometric freedom for friction control. Existing theories focus on translational sliding, while rotational friction dominated by Moiré boundaries and rotation centers remains underexplored. We present a theoretical framework for translational and rotational friction in circular and annular twisted bilayer graphene, deriving the geometric conditions for isotropic superlubricity. By an alyzing stable torsion angle scaling and its dependence on the rotation center, we explain the physical origin of translation-induced torsional oscillations. We establish scaling laws for maximum rotational torque, τ max ∝ R , and critical twist angle, θ max ∝ R − 1 . Extending the theory to annular geometries, we find that the normalized maximum torque and critical twist angle offset are universal functions of the inner-to-outer radius ratio, with annular structures inheriting the scaling behavior of circular disks. This study highlights the role of incomplete Moiré regions in friction control, offering a new theoretical perspective on the geometric origin of friction in 2D materials.扭曲双层石墨烯莫尔条纹超晶格为摩擦控制提供了独特的几何自由度。现有的理论主要集中在平移滑动，而由莫尔边界和旋转中心主导的旋转摩擦仍未得到充分研究。我们提出了一个理论框架的平移和旋转摩擦在圆形和环形扭曲双层石墨烯，导出了各向同性超润滑的几何条件。通过分析稳定扭转角尺度及其与旋转中心的关系，解释了平移引起扭转振荡的物理根源。建立了最大转矩τ max∝R和临界扭角θ max∝R−1的标度律。将该理论推广到环形几何中，发现归一化最大转矩和临界扭转角偏移量是内外半径比的通用函数，环形结构继承了圆盘的标度特性。本研究强调了不完全莫尔区在摩擦控制中的作用，为二维材料摩擦的几何起源提供了新的理论视角。Crack-tip shielding and toughening mechanis ms by architected microcellular zones in 3D-printed orthotropic materialsNavid Omidvar, Mirmilad Mirsayardoi:10.1016/j.ijsolstr.2026.114062三维打印正交各向异性材料的微孔区结构对裂纹尖端的屏蔽和增韧机制In this study, fracture resistance of 3D-printed orthotropic microcellular Acrylonitrile Butadiene Styrene (ABS) specimens was tailored by architecting porosity in the vicinity of a crack tip. Finite element simulations together with an an alytical approach based on crack-tip stress fields and fracture experiments were used to evaluate the effects of crack-tip microstructure and printing orientation (relative to crack axis) on the material’s fracture behavior. A circular region of interest (ROI) centered at the crack tip was defined, and the topology inside the ROI was considered a design variable, while the surrounding microcellular region remained unchanged. ROI topologies included a solid reference (REF), uniform voids (UNI), voids only behind the crack tip (CT), voids only ahead (CTI), and a random void distribution (Random). Fracture experiments were conducted, measuring fracture loads, and the dissipated energy was partitioned into two phases: pre-peak (up to P m a x ) and post-peak (from P m a x to 5% of P m a x ). The results showed that anisotropy plays a vital role, with roughly a 71% higher peak load and more than 3× higher dissipated energy in the 90° orientation than in the 0° orientation. Void placement dramatically dictates phase partitioning and toughness, and its effects show dependency on printing direction. CT-type specimens demonstrated shielding at initiation and yielded the highest strength in the 90° case, while CTI and UNI architectures dissipated extensive energy during the post-peak phase, demonstrating a transition from brittle-like interlayer fracture in the 0° case into a more ductile-like response, despite their reduced peak load. These findings show the capability of programming the fracture response in AM parts through microarchitecture, while revealing a tunable strength–toughness trade-off.在这项研究中，3d打印的正交各向异性微孔ABS （Acrylonitrile Butadiene Styrene， ABS）试样的抗断裂性通过在裂纹尖端附近构建孔隙度来定制。采用有限元模拟、基于裂纹尖端应力场的分析方法和断裂实验来评估裂纹尖端微观结构和印刷方向（相对于裂纹轴）对材料断裂行为的影响。定义了以裂纹尖端为中心的圆形感兴趣区域（ROI），并将ROI内的拓扑结构视为设计变量，而周围的微细胞区域保持不变。ROI拓扑包括固体参考（REF）、均匀空洞（UNI）、裂纹尖端后方的空洞（CT）、前方的空洞（CTI）和随机空洞分布（random）。进行了断裂实验，测量了断裂载荷，并将耗散能量分为两个阶段：峰前阶段（最高至ppm a x）和峰后阶段（从ppm a x到ppm a x的5%）。结果表明，各向异性起着至关重要的作用，90°取向的峰值载荷比0°取向高71%，耗散能量比0°取向高3倍以上。孔洞的放置对相分配和韧性有显著影响，其影响与打印方向有关。ct型试样在初始阶段表现出屏蔽作用，并在90°情况下产生最高强度，而CTI和UNI结构在峰后阶段消耗了大量能量，表明从0°情况下的脆性层间断裂转变为更类似延性的响应，尽管它们的峰值载荷降低了。这些发现表明，通过微结构对增材制造部件的断裂响应进行编程的能力，同时揭示了可调的强度-韧性权衡。Journal of the Mechanics and Physics of SolidsMechanistic Origins of Toughness in Random Fibrin Fiber NetworksBeikang Gu, Jixin Hou, Keke Tang, He Li, Xianqiao Wangdoi:10.1016/j.jmps.2026.106669随机纤维蛋白纤维网络韧性的机械起源Fibrin fibers form the fundamental load-bearing skeleton of blood clots and determine their stability and routes to failure. Understanding the rupture behavior of fibrin fiber networks is therefore essential for clarifying the mechanics in the process of thrombus formation, persistence, and removal. Here, we develop a coarse-grained fibrin-fiber model and a workflow to generate biomimetic random fibrin fiber networks that capture the microstructural variation of fibrin network during clot deformations. Using this framework, we systematically investigate how junction density, specimen width-to-length ratio, initial crack length, and fiber tortuosity govern network deformation and rupture. Our results reveal that rupture dynamics are largely controlled by the deformational freedom of fiber segments (fibers spanning between two junctions), which dictates the rupture sequence and the redistribution of load upon local failure. Increasing junction density in networks yields s moother stress–strain responses, whereas sparse networks fail through discrete, geometry-specific rupture events. In contrast to continuum fracture, rupture propagation in fibrin fiber networks is dominated by segment-to-segment strain heterogeneity induced by necking, which drives failure across crack and connector zones. The width-to-length ratio modulates rupture by changing the number of load-bearing fibers, whereas fiber tortuosity increases segment length, enhances deformational freedom, and improves fracture toughness. Together, these findings identify deformational freedom as a unifying principle that links geometry, mechanics, and rupture in fibrin fiber networks. By clarifying how structural parameters dictate fracture toughness and failure pathways, this work advances a mechanistic understanding of thrombus rupture and may help inform strategies for assessing rupture risks and guiding surgical thrombectomy.纤维蛋白纤维形成血块的基本承重骨架，并决定其稳定性和失败的途径。因此，了解纤维蛋白纤维网络的断裂行为对于阐明血栓形成、持续和去除过程中的机制至关重要。在这里，我们开发了一个粗粒度的纤维蛋白纤维模型和一个工作流来生成仿生随机纤维蛋白纤维网络，以捕获纤维蛋白网络在凝块变形过程中的微观结构变化。利用这一框架，我们系统地研究了结密度、试样宽长比、初始裂纹长度和纤维弯曲度如何影响网络变形和断裂。我们的研究结果表明，断裂动力学在很大程度上是由纤维段的变形自由控制的（纤维跨越在两个结点之间），这决定了断裂顺序和局部破坏时载荷的重新分配。增加网络中的结密度会产生更平滑的应力-应变响应，而稀疏网络则会通过离散的、几何特定的破裂事件而失效。与连续断裂相比，纤维蛋白纤维网络中的断裂扩展主要受颈缩引起的段间应变非均质性影响，从而导致裂纹和连接区域的破坏。宽度与长度比通过改变承载纤维的数量来调节断裂，而纤维的扭曲度增加了线段长度，增强了变形自由度，提高了断裂韧性。总之，这些发现确定变形自由是连接纤维蛋白纤维网络的几何、力学和断裂的统一原则。通过阐明结构参数如何决定断裂韧性和失效途径，这项工作推进了对血栓破裂的机制理解，并可能有助于评估破裂风险和指导手术取栓的策略。Constitutive parameter inference using physics-informed full volume inverse modeling of intact and torn rotator cuff tendonsCarla Nathaly Villacís Núñez, Siddhartha Srivastava, Ulrich Scheven, Asheesh Bedi, Krishna Garikipati, Ellen M. Arrudadoi:10.1016/j.jmps.2026.106668 利用完整和撕裂肌腱的物理信息全体积逆建模进行本构参数推断In this work, we characterized the material properties of an animal model of the rotator cuff tendon using full volume datasets of its intact and injured states. Unlike conventional approaches relying on surface strains or excised specimens, our framework leverages voxel-wise displacement data to infer constitutive behavior while preserving native architecture. Our experimental setup activated volumetric, tensile, and shear mechanis ms given the tendon’s complex geometry. We implemented an approach to model inference termed variational system identification (VSI) to solve the weak form of the stress equilibrium equation using these full volume displacements, enabling identification of dominant deformation mechanis ms. Three constitutive models were used for parameter inference: a neo-Hookean model, a modified Holzapfel-Gasser-Ogden (HGO) model with higher-order terms in the first and second invariants, and a reduced polynomial model based on the first, second, and fiber-related invariants. VSI-inferred parameters were further refined using an adjoint-based partial differential equation (PDE)-constrained optimization framework. The modified HGO model captures the tendon’s deformation mechanis ms with reasonable accuracy, while the neo-Hookean model fails to reproduce key internal features, particularly the shear behavior in injured tendons. Surprisingly, the simplified polynomial model performs comparably to the modified HGO formulation using only three terms. These findings suggest that while current constitutive models do not fully replicate the complex internal mechanics of the tendon, they can capture key trends in intact and damaged tissue, using a homogeneous modeling approach. Continued model development is needed to bridge this gap and enable clinical-grade, predictive simulations of tendon injury and repair.在这项工作中，我们使用完整的肌腱和损伤状态数据集来表征动物模型的材料特性。与依赖于表面应变或切除标本的传统方法不同，我们的框架利用体素位移数据来推断本构行为，同时保留本地建筑。我们的实验装置激活了体积、拉伸和剪切机制，考虑到肌腱的复杂几何形状。我们实施了一种称为变分系统识别（VSI）的模型推理方法，利用这些全体积位移来求解应力平衡方程的弱形式，从而能够识别主要的变形机制。采用三种本构模型进行参数推断：新hookean模型、第一和第二不变量中含有高阶项的改进holzapfeld - gasser - ogden （HGO）模型，以及基于第一、第二和纤维相关不变量的简化多项式模型。使用基于伴随的偏微分方程（PDE）约束优化框架进一步细化vsi推断参数。改进的HGO模型以合理的精度捕获了肌腱的变形机制，而新hookean模型未能再现关键的内部特征，特别是损伤肌腱的剪切行为。令人惊讶的是，简化的多项式模型的性能与仅使用三个项的改进HGO公式相当。这些发现表明，虽然目前的本构模型不能完全复 制肌腱复杂的内部力学，但它们可以使用均匀的建模方法捕获完整和受损组织的关键趋势。需要持续的模型开发来弥补这一差距，并使临床级、预测肌腱损伤和修复的模拟成为可能。Thin-Walled StructuresDuctile failure and strength prediction of thread-anchored blind bolt with thread-extensionBo Yang, Yang Xiang, Guo-Qiang Li, Wen-Jun Shidoi:10.1016/j.tws.2026.115069螺纹锚杆延性破坏及强度预测This work introduces and investigates a novel thread-anchored blind-bolt (TAB) configuration, designated as the TAB with thread-extension and hereafter abbreviated as TABE. Static tensile tests were performed on 24 specimens, comprising 18 TABE specimens and 6 conventional TAB counterparts. While earlier studies have thoroughly examined brittle failure modes such as thread stripping and bolt fracture, the present research focuses on the ductile failure mode of the TABE connection, in which wall yielding of the closed-section steel (CSS) member governs both strength and deformability. The attached plate effectively mitigates the stress concentration characteristic of TAB connections and promotes a more compatible deformation pattern in the CSS wall. Experimental and numerical results show that the TABE configuration substantially enhances joint tensile strength, with improvements of 200% ~ 300%, while ultimate deformation increases by 130% ~ 191% in rationally designed cases, achieving significantly improved ductility. Based on classical yield-line theory, a mechanical model is developed to estimate the design tensile strength of TABE connections. Design recommendations for key parameters are provided.本工作介绍并研究了一种新型螺纹锚定盲螺栓（TAB）配置，称为带螺纹扩展的TAB，以下简称TABE。对24个试件进行了静态拉伸试验，其中18个为TABE试件，6个为常规TABE试件。虽然早期的研究已经深入研究了脆性破坏模式，如螺纹剥离和螺栓断裂，但目前的研究主要集中在table连接的延性破坏模式上，其中闭截面钢（CSS）构件的壁屈服决定了强度和变形能力。附板有效地缓解了TAB连接的应力集中 特性，促进了CSS墙内更协调的变形模式。实验和数值结果表明，在合理设计的情况下，TABE配置可显著提高接头抗拉强度，提高200% ~ 300%，而极限变形增加130% ~ 191%，显著提高延性。基于经典屈服线理论，建立了TABE连接设计抗拉强度的力学模型。给出了关键参数的设计建议。Superelastic S MA Omega dampers for seis mic resilience: Development, Tests, and Numerical simulationShuling Hu, Jinmeng Zang, Tong Guo, Zhipeng Chen, Theodoros L. Karavasilis, M. Shahria Alam, Vasileios Kamperidisdoi:10.1016/j.tws.2026.115068用于地震恢复的超弹性S MA Omega阻尼器：开发，测试和数值模拟This paper aims to develop a novel shape memory alloy (S MA) Omega damper (denoted as S MA-Ω damper) as a new self-centering component for developing seis mic resilient engineering structures. The mechanical behavior and deformation mechanis m of the S MA-Ω damper are presented first. Experimental tests are subsequently conducted to investigate its hysteretic behavior and failure mode under cyclic loadings. Test results confirm that the proposed S MA-Ω dampers can achieve reliable self-centering performance with negligible residual deformations under cyclic loadings. Par ametric numerical studies are further carried out to understand the strain and stress development in S MA-Ω dampers under cyclic loading and to investigate the influence of design parameters. Parametric an alyses reveal that the geometric parameters t, R, r, and d 1 govern stiffness, strength, and strain distribution. Larger thickness (t), s maller radii (R, r), and shorter transition lengths (d 1) increase stiffness, strength, and energy-dissipation capacity but may induce stress concentration and reduce deformation capacity. Based on the test and numerical results, the design recommendations of S MA-Ω dampers are finally proposed.本文旨在研制一种新型形状记忆合金(S MA) ω阻尼器（简称S MA-Ω阻尼器），作为一种新型的自定心构件，用于发展抗震工程结构。首先介绍了S MA-Ω阻尼器的力学性能和变形机理。随后进行了试验试验，以研究其在循环载荷下的滞回行为和破坏模式。试验结果证实，所提出的S MA-Ω阻尼器在循环载荷下具有可靠的自定心性能，残余变形可以忽略不计。为进一步了解S MA-Ω阻尼器在循环荷载作用下的应变和应力发展规律，并研究设计参数对阻尼器的影响，进行了参数化数值研究。参数分析表明，几何参数t， R， R和d1控制刚度，强度和应变分布。较大的厚度(t)、较小的半径（R， R）和较短的过渡长度（d1）增加了刚度、强度和耗能能力，但可能引起应力集中并降低变形能力。在试验和数值结果的基础上，提出了S MA-Ω阻尼器的设计建议。Model predictive vibration control for a six-degree-of-freedom rigid-flexible coupled parallel platformZheng Xing, Jie Tang, Qiang Min, Meng Li, Yinghui Li, Huatao Chen, Dengqing Caodoi:10.1016/j.tws.2026.115061六自由度刚柔耦合并联平台模型预测振动控制The six-degree-of-freedom (6-DOF) platform is extensively employed for positioning, pointing, and vibration isolation in aerospace, marine, and precision machinery applications. However, the classical Gough-Stewart configuration suffers from joint backlash and friction, and its dynamic performance degrades under high-frequency vibration, thereby compromising operational accuracy. Recently, rigid–flexible coupled structures have attracted considerable attention because judicious kinematic design can eliminate the above shortcomings while offering superior isolation and transient response. This paper investigates a 6-DOF rigid–flexible coupling parallel platform. The dynamic equations are derived by recourse to Timoshenko beam theory and the generalized Hamilton principle. Global mode shapes are extracted through the Global Mode Method (GMM), and the natural frequencies of the rigid–flexible assembly are computed and benchmarked against finite-element predictions. The governing ordinary differential equations are subsequently converted into a state- space representation. The Model Predictive Control (MPC) system, which relies on piezoelectric actuation, is then synthesized based on the global mode model. Following the optimal tuning of the control hyper-parameters, numerical vibration isolation simulations are conducted under a variety of service conditions and the results are critically evaluated. The simulations demonstrate that the parallel platform provides excellent 6-DOF isolation against various excitations, thereby confirming the effectiveness of the proposed piezoelectric active isolation system under MPC. The study provides a dynamic modelling framework that is both accurate and computationally efficient, together with an MPC controller for six-degree-of-freedom rigid–flexible coupled parallel platforms operating in vibratory environments. It also offers theoretical guidance and engineering insights into the optimal placement of piezoelectric actuators and control strategy design in parallel kinematic machines.六自由度（6-DOF）平台广泛用于航空航天，船舶和精密机械应用中的定位，指向和隔振。然而，经典的Gough-Stewart结构受到关节隙和摩擦的影响，其动态性能在高频振动下下降，从而影响了操作精度。最近，刚柔耦合结构引起了人们的广泛关注，因为合理的运动学设计可以消除上述缺点，同时提供良好的隔离和瞬态响应。研究了一种六自由度刚柔耦合并联平台。利用Timoshenko梁理论和广义Hamilton原理推导了动力学方程。通过全局模态法（GMM）提取全局模态振型，计算刚柔装配的固有频率，并根据有限元预测对其进行基准测试。控制常微分方程随后被转换成状态空间表示。基于全局模态模型合成了基于压电驱动的模型预测控制（MPC）系统。在对控制超参数进行最优整定后，在多种使用条件下进行了数值隔振仿真，并对结果进行了批判性评价。仿真结果表明，并联平台对各种激励具有良好的六自由度隔离效果，从而验证了压电主动隔离系统在MPC下的有效性。该研究为在振动环境中工作的六自由度刚柔耦合并联平台提供了一个精确且计算效率高的动态建模框架，以及MPC控制器。它还为并联机构中压电致动器的最佳放置和控制策略设计提供了理论指导和工程见解。来源：复合材料力学仿真Composites FEM
