【新文速递】2024年9月25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 2 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 1 篇

International Journal of Solids and Structures

A rheological constitutive model to predict the anisotropic biaxial bending behavior of spiral strands subjected to variable axial force

Mohammad Ali Saadat, Damien Durville

doi:10.1016/j.ijsolstr.2024.113082

用流变本构模型预测螺旋股在变轴力作用下的各向异性双轴弯曲行为

Spiral strands exhibit dissipative bending behavior when subjected to external axial force. To the best of the authors’ knowledge, only the uniaxial bending behavior of spiral strands subjected to constant axial force has been studied in the literature so far. Thanks to a recently developed mixed stress–strain driven computational homogenization for spiral strands, this paper is the first to study the biaxial bending behavior of spiral strands subjected to variable tensile force. Based on the observed anisotropic behavior, a rheological constitutive model equivalent to multilayer spiral strands is proposed to predict their behavior under such loading. For an N l -layer strand, the proposed model consists of several angularly distributed uniaxial spring systems, referred to as a multiaxial spring system, where each uniaxial spring system consists of a spring and N l slider-springs. In a uniaxial spring system, the spring represents the slip contribution of all wires to the bending stiffness of the strand, while each slider-spring represents the stick contribution of each layer. A major advantage of the proposed scheme is its straightforward parameter identification, requiring only several monotonic uniaxial bendings under constant axial force. The proposed rheological model has been verified against the responses obtained from the mixed stress–strain driven computational homogenization through several numerical examples. These examples consist of complex uniaxial and biaxial load cases with variable tensile force. It has been shown that the proposed scheme not only predicts the response of the strand, but also provides helpful insight into the complex underlying mechanism of spiral strands. Furthermore, the low computational cost of the proposed models makes them perfect candidates for implementation as a constitutive law in a beam model. Using a single beam with the proposed constitutive law, spiral strand simulations can be performed in a few seconds on a laptop instead of a few hours or days on a supercomputer.

当受到外部轴向力时，螺旋股表现出耗散弯曲行为。据作者所知，迄今为止，文献中只研究了螺旋股在恒定轴向力作用下的单轴弯曲行为。由于最近发展了螺旋股的混合应力-应变驱动的计算均匀化，本文首次研究了螺旋股在变拉力作用下的双轴弯曲行为。基于观察到的各向异性行为，提出了一种相当于多层螺旋股的流变本构模型来预测其在这种载荷下的行为。对于N - 1层钢绞线，所提出的模型由几个角度分布的单轴弹簧系统组成，称为多轴弹簧系统，其中每个单轴弹簧系统由弹簧和N - 1滑动弹簧组成。在单轴弹簧系统中，弹簧代表所有钢丝对钢绞线弯曲刚度的滑移贡献，而每个滑动弹簧代表每层的粘滞贡献。该方案的一个主要优点是参数识别简单，只需要在恒定轴向力下进行几次单调单轴弯曲。通过数值算例验证了所提出的流变模型与混合应力-应变驱动计算均质化的响应。这些例子包括复杂的单轴和双轴载荷情况下的可变拉伸力。研究表明，所提出的方案不仅预测了螺旋链的响应，而且为了解螺旋链的复杂潜在机制提供了有益的见解。此外，所提出的模型的低计算成本使其成为梁模型中本构律的完美候选。使用单束和提出的本构律，螺旋链模拟可以在笔记本电脑上几秒钟完成，而不是在超级计算机上几个小时或几天。

Unravelling electromechanical mechanism of mechanoreceptor inspired capacitive pressure sensor considering size effect

Wenxuan Ding, Yonglin Chen, Wenbin Kang, Zhuangjian Liu, Peng Wang, Weidong Yang

doi:10.1016/j.ijsolstr.2024.113083

考虑尺寸效应的机械感受器启发电容式压力传感器的解耦机电机理

The rapid development of intelligent sensing technologies, including electronic skins, wearable devices and robots, has put forward an urgent demand for various tactile biomimetic sensors. However, the design of tactile sensors is mostly based on independent experimental research and lack theoretical guidance at present. In this work, drawing inspiration from human skin microstructure mechanoreceptors responsible for tactile sensation, we proposed a capacitive pressure sensor model featuring a biomimetic conformal microstructured electrode with a round-crown shape. Moreover, at the micrometer scale, size effect profoundly influences the mechanical behavior of sensing materials and microstructured devices. Firstly, we conducted in-depth research on the electromechanical behavior of conformal microstructured electrode pressure sensor, considering the size effect based on couple stress elasticity and Hertz contact theory. We validated the effectiveness of the model by comparing it with experimental and simulation results of human skin. Through numerical simulation, we further verified that the theoretical model of a single microstructured electrode can be utilized for calculating microstructured electrode arrays. Furthermore, our analysis reveals that the geometric morphology and material properties of the dielectric layer, the arrangement density of the microstructured electrode arrays, along with the radius of the round-crown shaped microstructured electrode are the dominant parameters influencing the electromechanical sensitivity through parameter analysis. Finally, we devised a high-k (high dielectric permittivity) polymer composites dielectric layer with a tunable Poisson’s ratio structure, offering feasible approach to achieving highly sensitive capacitive microstructure sensors. This theoretical model that takes into account the size effect in microstructured electrode contact problem provides theoretical insights that can guide the optimization design of high-performance tactile sensors.

电子皮肤、可穿戴设备、机器人等智能传感技术的快速发展，对各种触觉仿生传感器提出了迫切的需求。然而，目前触觉传感器的设计多基于独立的实验研究，缺乏理论指导。在这项工作中，我们从负责触觉的人体皮肤微观结构机械感受器中获得灵感，提出了一种具有圆形冠状仿生共形微结构电极的电容式压力传感器模型。此外，在微米尺度上，尺寸效应深刻地影响着传感材料和微结构器件的力学行为。首先，基于耦合应力弹性和赫兹接触理论，考虑尺寸效应，对共形微结构电极压力传感器机电性能进行了深入研究。通过与人体皮肤实验和仿真结果的对比，验证了该模型的有效性。通过数值模拟，我们进一步验证了单个微结构电极的理论模型可以用于计算微结构电极阵列。此外，通过参数分析，我们的分析表明介电层的几何形态和材料特性，微结构电极阵列的排列密度以及圆冠状微结构电极的半径是影响机电灵敏度的主要参数。最后，我们设计了一种具有可调泊松比结构的高k(高介电常数)聚合物复合材料介电层，为实现高灵敏度电容性微结构传感器提供了可行的途径。该理论模型考虑了微结构电极接触问题中的尺寸效应，为高性能触觉传感器的优化设计提供了理论指导。

Journal of the Mechanics and Physics of Solids

An analytic traction-displacement model for a reinforcing ligament bridging a crack at an arbitrary angle, including elastic, frictional, snubbing, yielding, creep, and fatigue phenomena.

B.N. Cox, N. Sridhar, Q.D. Yang

doi:10.1016/j.jmps.2024.105879

以任意角度桥接裂缝的加固韧带的牵拉-位移解析模型，包括弹性、摩擦、弯曲、屈服、蠕变和疲劳现象。

A micromechanical model is developed that generates analytic expressions for the crack displacement vector u given an arbitrary far-field stress state σa for a crack that is bridged by an array of ligaments oriented at an arbitrary angle with respect to the crack plane. The model is applicable to various materials, e.g., fibrous ceramic composites, or polymer composites reinforced by stitches or z-pins or woven tows, and deals with interfacial friction, enhanced friction due to increased contact pressure (“snubbing”), and the possibility of ligament deflection enabled by yield or damage. The model also conveniently incorporates ligament failure and rate dependent phenomena (fatigue or creep). Adaptability of the model is enabled by the definition of a standard Reference Model, which generates analytic expressions for the crack displacement for given possible yield, ligament deflection, and friction and snubbing effects and is invariant for all geometrical and material choices. The switching on or off and the strengths of all phenomena are governed by assigning values to a handful of material parameters. The material parameters will generally be calibrated against data in a top-down strategy, the model thereby mapping material selection onto engineering fracture via the predicted bridging relationship u[σa]. The relationship u[σa] can depend strongly on bi-angular ligament orientation. Yield and deflection can change u[σa] qualitatively, e.g., by creating fracture surface contact even when σa includes substantial opening tension. Snubbing has significant effects, including possible stabilization of the pullout of a finite ligament. Since model output is computed via analytic expressions, its speed will support the model's use in large-scale material simulations or as constraining physical information in machine learning algorithms.

本研究开发了一种微观力学模型，在给定任意远场应力状态 σa 的情况下，可生成裂纹位移矢量 u 的解析表达式，该裂纹由相对于裂纹平面以任意角度定向的韧带阵列桥接。该模型适用于各种材料，例如纤维状陶瓷复合材料，或通过缝合线、Z 形针或编织丝束加固的聚合物复合材料，并可处理界面摩擦、因接触压力增大（“挤压”）而增强的摩擦，以及因屈服或损坏而导致韧带变形的可能性。该模型还可方便地纳入韧带失效和速率相关现象（疲劳或蠕变）。标准参考模型可生成给定屈服、韧带挠度、摩擦和挤压效应下裂纹位移的解析表达式，并在所有几何和材料选择下保持不变。所有现象的开启或关闭以及强度都受一些材料参数值的制约。材料参数一般采用自上而下的策略根据数据进行校准，模型通过预测的桥接关系 u[σa] 将材料选择映射到工程断裂上。u[σa]关系在很大程度上取决于双角韧带的走向。屈服和挠曲可以从本质上改变 u[σa]，例如，即使 σa 包括很大的张开张力，也会产生断裂面接触。挤压会产生重大影响，包括可能稳定有限韧带的拉伸。由于模型输出是通过解析表达式计算的，其速度将支持模型用于大规模材料模拟或作为机器学习算法中的约束物理信息。

A multiscale Bayesian method to quantify uncertainties in constitutive and microstructural parameters of 3D-printed composites

Xiang Hong, Peng Wang, Weidong Yang, Junming Zhang, Yonglin Chen, Yan Li

doi:10.1016/j.jmps.2024.105881

三维打印复合材料本构和微观结构参数不确定性的多尺度贝叶斯量化方法

3D-printed continuous carbon fiber reinforced composites (CCFRCs) are promising for various engineering applications due to high strength-to-weight ratios and design flexibility. However, the large variations in their mechanical properties pose a considerable challenge to their widespread applications. Here we develop a multiscale Bayesian method to quantify uncertainties in the constitutive parameters and microstructural parameters of 3D-printed CCFRCs. Based on the characterized microstructure of CCFRCs, a multiscale micromechanical model is developed to reveal the relationship between the properties of constituent materials, the microstructural parameters, and the macroscopic constitutive parameters. Furthermore, the joint posterior probability distribution of these parameters is formulated, and the Markov Chain Monte Carlo method (MCMC) is used to compute the posterior distributions of constitutive and microstructural parameters, enabling assessment of parameter uncertainty, correlation, and model calibration error. The inferred microstructural parameters are consistent with those measured by experiments. The posterior predictive distributions of the constitutive response are further computed to validate the probability model. Our method quantifies uncertainties in the constitutive parameters of 3D-printed CCFRCs and identifies their origins, which can optimize constituent material properties and microstructural parameters to achieve more robust composites.

3d打印连续碳纤维增强复合材料(CCFRCs)由于其高强度重量比和设计灵活性，在各种工程应用中都很有前景。然而，其机械性能的巨大变化对其广泛应用构成了相当大的挑战。本文提出了一种多尺度贝叶斯方法来量化3d打印CCFRCs的本构参数和微观结构参数的不确定性。基于CCFRCs的微观结构特征，建立了CCFRCs的多尺度细观力学模型，揭示了组成材料性能、微观结构参数和宏观本构参数之间的关系。在此基础上，建立了这些参数的联合后验概率分布，并利用马尔可夫链蒙特卡罗方法(MCMC)计算了本构参数和微观结构参数的后验分布，从而评估了参数的不确定性、相关性和模型校准误差。推断出的微观结构参数与实验测量结果一致。进一步计算了本构响应的后验预测分布，验证了概率模型。我们的方法量化了3d打印CCFRCs本构参数中的不确定性，并确定了它们的来源，从而可以优化组成材料的性能和微观结构参数，以获得更坚固的复合材料。

Mechanics of Materials

Atomistic investigation on the anisotropic elastic and plastic responses of nanotwinned metals

Ligang Sun, Lianyu Jiao, Zhijia Qin, Linli Zhu, Bin Gan, Dongfeng Li

doi:10.1016/j.mechmat.2024.105164

纳米孪晶金属各向异性弹塑性响应的原子性研究

Introducing nanotwins into materials is one of the important strengthening methods to achieve the synergistic improvement of strength and ductility. The anisotropic mechanical behaviors of nanotwinned materials have been widely studied by experimental and computational methods. The dominant deformation mechanisms about dislocation slippages can be effectively switched among three modes, and controlled by twin spacing and the angle between twin boundaries (TBs) orientation and loading direction. Particularly, most of previous researches mainly focused on the deformation mechanisms during the plastic flow stage and researchers paid little attention on the anisotropic characteristics of TBs at the elastic stage which are also essential to manufacture the high-performance materials. Therefore, this study is aiming to systemically investigate the anisotropic effect of TBs both on the elastic and plastic stages within the single crystalline or polycrystalline by molecular dynamics (MD) simulations. It is revealed that, when the loading direction is parallel to twin planes, the introduction of TBs in single crystalline models will significantly affect the characteristics of atomic bond rotation and elongation dominated elastic deformation, which can alter the Poisson’s ratio of materials, generate elastic-softening behavior and inhomogeneous elastic deformation. At the plastic flow stage, the deformation mechanism transforms from trans-twin dislocation slippage into the coexistence of Hard Mode I and threading dislocation slippage (Hard Mode II) when the loading direction changes from parallel to perpendicular direction with respect to TBs. However, both the elastic and plastic behaviors are less sensitive to TBs in vertical direction. Moreover, the dislocation segments at the conjunction of trans-twin dislocation play a momentous role in enhancing material strength. The results for polycrystalline models are consistent with that of single crystalline ones. These findings are expected to be beneficial for the development of high-performance nanostructured materials for structural and functional applications by strain engineering and defect regulation.

在材料中引入纳米孪晶是实现材料强度和塑性协同提高的重要强化方法之一。纳米孪晶材料的各向异性力学行为已经通过实验和计算方法得到了广泛的研究。位错滑移的主导变形机制可以在三种模式之间有效切换，并受孪晶间距和孪晶边界取向与加载方向夹角的控制。特别是，以往的研究大多集中在塑性流动阶段的变形机理上，而对弹性阶段的各向异性特性研究较少，而弹性阶段的各向异性特性对高性能材料的制造至关重要。因此，本研究旨在通过分子动力学(MD)模拟系统地研究TBs在单晶或多晶中弹性和塑性阶段的各向异性效应。结果表明，当加载方向平行于双平面时，TBs的引入将显著影响单晶模型中原子键旋转和伸长主导的弹性变形特性，从而改变材料的泊松比，产生弹性软化行为和非均匀弹性变形。在塑性流动阶段，当加载方向相对于TBs由平行方向变为垂直方向时，变形机制由跨孪位错滑移转变为硬模式I和螺纹位错滑移(硬模式II)并存。然而，在垂直方向上，弹性和塑性行为对TBs都不太敏感。跨孪位错结合处的位错段对提高材料强度有重要作用。多晶模型的结果与单晶模型的结果一致。这些发现将有助于通过应变工程和缺陷调节来开发用于结构和功能应用的高性能纳米结构材料。

International Journal of Plasticity

Tailoring thickness debit for high-temperature fatigue resistance of Inconel 718 superalloy fabricated by laser powder bed fusion

Tao Ma, Bin Zhang, Li-Ming Lei, Yuan-Chen Wang, Zhu-Man Song, Guang-Ping Zhang

doi:10.1016/j.ijplas.2024.104137

激光粉末床熔合法制备因康乃尔718高温合金的耐高温疲劳性能

The thickness debit often leads to uncertainty regarding the fatigue performance of laser powder bed fusion (LPBF)-fabricated Inconel 718 thin-walled components and restricts the structural design of these components. Aiming to address this issue, fatigue properties of LPBF-fabricated Inconel 718 homogenized at various temperatures were investigated at 650°C using specimens with different thicknesses. The results reveal a pronounced influence of both the thickness debit and the intricate interplay between the microstructural and geometrical scales of the thin-walled specimens on their fatigue life at 650°C. The fatigue life of the thin-wall specimens with the same microstructural scale reduces with decreasing the ratio (t/d) of the specimen thickness (t) to the grain length (d). The coupling effect is described by a mechanism model correlated with the geometrical and microstructural scales of the specimens, in which continuous damage mechanics (CDM) and calculation of the yield strength have been considered. Based on the model, a criterion of t/d > 6.2 for the LPBF-fabricated Inconel 718 specimens homogenized at 1100°C, and t/d > 8.8 for those homogenized at 1065°C are proven to be satisfied to ensure a longer and more stable fatigue life of the thin-walled specimens serving at 650°C. Elevating the homogenization temperature from 1065°C to 1100°C results in an extension of the fatigue life for specimens of the same thickness. This enhancement is attributed to the improved ability of grains to coordinate local deformation, as well as the reduced prevalence of elongated Laves and other phases, which typically serve as preferential sites for crack initiation and propagation. The finding suggests that the thickness debit in high-temperature fatigue resistance of LPBF-fabricated components can be minimized by tailoring the heat treatment strategy.

厚度偏差经常导致激光粉末床熔合(LPBF)制造的Inconel 718薄壁部件疲劳性能的不确定性，并限制了这些部件的结构设计。为了解决这一问题，在650℃下，使用不同厚度的试样，研究了lpbf制备的Inconel 718在不同温度下均质化的疲劳性能。结果表明，薄壁试样在650℃下的疲劳寿命受到厚度偏差和微观组织与几何尺度之间复杂的相互作用的显著影响。相同显微组织尺度下薄壁试样的疲劳寿命随着试样厚度与晶粒长度之比(t/d)的减小而减小。本文建立了考虑连续损伤力学和屈服强度计算的与试样几何和显微组织尺度相关的力学模型来描述这种耦合效应。基于该模型，在1100℃下均质化lpbf制备的Inconel 718薄壁试样满足t/d > 6.2准则，在1065℃下均质化的Inconel 718薄壁试样满足t/d > 8.8准则，可保证650℃下薄壁试样具有更长的稳定疲劳寿命。将均匀化温度从1065℃提高到1100℃，可以延长相同厚度试样的疲劳寿命。这种增强是由于晶粒协调局部变形的能力提高，以及拉长的Laves和其他相的流行减少，而这些相通常是裂纹萌生和扩展的首选部位。这一发现表明，通过调整热处理策略可以最大限度地减少lpbf制造的部件的高温疲劳抗力的厚度损失。

Thin-Walled Structures

Theoretical prediction and experimental validation of flexural behaviour and failure modes of 3D-woven honeycomb sandwich panels

Prabhjot Singh, Sameer K Behera, Omender Singh, Javed Sheikh, B K Behera

doi:10.1016/j.tws.2024.112481

三维编织蜂窝夹层板抗弯性能及破坏模式的理论预测与试验验证

This study presents a novel approach to enhance the flexural performance of sandwich composite panels by introducing 3D-woven honeycomb (HC) composites as core material. The flexural performance and failure modes of these novel structures are compared with traditional aluminium honeycombs across various facesheet materials. Experimental findings are complemented by numerical analyses, while observed failure modes are compared with theoretical flexural failure modes. The results reveal that 3D-woven Kevlar HC cores demonstrate superior flexural stiffness and strength due to its integrated structure, while enhanced energy absorption is attributed to unique deformation mechanisms within the 3D-woven core. Failure modes observed in the experiments closely aligned with theoretical predictions, further validating the approach. Overall, the findings validate the potential of novel 3D-woven Kevlar HC cores as promising alternatives for lightweight, high-performance sandwich composite panels.

本文提出了一种采用三维编织蜂窝复合材料作为芯材来提高夹层复合板抗弯性能的新方法。这些新型结构的弯曲性能和破坏模式与传统的铝蜂窝在不同的面板材料进行了比较。数值分析补充了实验结果，并将观察到的破坏模式与理论的弯曲破坏模式进行了比较。结果表明，3d编织的凯夫拉纤维HC芯由于其整体结构而具有优越的抗弯刚度和强度，而增强的能量吸收归因于3d编织芯内部独特的变形机制。实验中观察到的失效模式与理论预测密切相关，进一步验证了该方法。总的来说，研究结果验证了新型3d编织Kevlar HC芯作为轻质高性能夹层复合板的有希望的替代品的潜力。