【新文速递】2024年7月15日固体力学SCI期刊最新文章

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今日更新：International Journal of Solids and Structures 1 篇，Journal of the Mechanics and Physics of Solids 1 篇，International Journal of Plasticity 1 篇

International Journal of Solids and Structures

Peeling of periodically heterogeneous film from rigid substrate at arbitrary peeling angle

Chuang-Shi Shen, Huan-Fang Wang, Fei Yao, Jing-Liang Cui, Bo Zhou, Xi-Ning Zhao, Yong-Wang Zhang, Bo Li, Ze-Wei Li

doi:10.1016/j.ijsolstr.2024.112976

以任意剥离角度从刚性基材上剥离周期性非均匀薄膜

Although it is acknowledged that using periodically heterogeneous film can improve adhesion properties without interface modification, there is still a lack of comprehensive research in the existing literature that specifically investigates the behavior of peeling of such film from rigid substrate at arbitrary peeling angle. To this end, two theoretical models, an accurate and an approximate model, for the peeling of periodically heterogeneous film at arbitrary peeling angle are proposed in this study. The primary focus of the present study is on examining the peeling behavior of such film, with special attention given to the impact of peeling angle on the peeling behavior. Our analysis revealed two unknown peeling behaviors. Firstly, the use of periodically heterogeneous film not only enhance the adhesion performance of its stiff section, but also weakens the adhesion performance of its compliant section. Secondly, the enhancing ratio of adhesion performance does not remain constant, nor does it exhibit a monotonically increasing function with the peeling angle. Instead, it initially increases and then decreases as the peeling angle increases. The weakening ratio of adhesion performance with respect to the peeling angle is similar to that of the enhancing ratio. The influence of several parameters, including the bending stiffness ratio, adhesion energy, bending stiffness of the compliant section, period length of the periodically heterogeneous film, and length fraction of the stiff section, on the peeling of periodically heterogeneous film at arbitrary peeling angle are also studied. Based on the accurate theory, a formula for calculating the peeling force of homogeneous film is also derived. The calculated results using the proposed formula are in excellent agreement with the classical Kendall theory

虽然人们已经认识到，在不改变界面的情况下，使用周期性的非均相薄膜可以改善附着性能，但现有文献中还缺乏全面的研究，专门研究这种薄膜在任意剥离角度下从刚性基体上剥离的行为。为此，本文提出了任意剥离角度下周期性非均质薄膜剥离的精确模型和近似模型。本研究的主要重点是研究这种薄膜的剥离行为，并特别关注剥离角度对剥离行为的影响。我们的分析揭示了两种未知的剥落行为。首先，周期性非均质膜的使用不仅增强了其刚性部分的粘附性能，而且削弱了其柔顺部分的粘附性能。其次，粘附性能的增强比并不是恒定不变的，也不是随剥离角度的变化呈单调递增的函数。相反，它会随着剥离角度的增大先增大后减小。粘附性能随剥离角的减弱比与增强比相似。研究了弯曲刚度比、附着能、柔顺截面的弯曲刚度、周期性非均质膜的周期长度和刚性截面的长度分数等参数对任意剥离角度下周期性非均质膜剥离的影响。在精确理论的基础上，导出了均匀膜剥离力的计算公式。用该公式计算的结果与经典肯德尔理论非常吻合

Journal of the Mechanics and Physics of Solids

A Mechanics and Electromagnetic Scaling Law for Highly Stretchable Radio Frequency Electronics

Zichen Zhao, Raudel Avila, Dongjun Bai, Danli Xia, Enxi She, Yonggang Huang, John A. Rogers, Zhaoqian Xie

doi:10.1016/j.jmps.2024.105784

高可拉伸射频电子学的力学与电磁标度律

Many classes of flexible and stretchable bio-integrated electronic systems rely on mechanically sensitive electromagnetic components, such as various forms of antennas for wireless communication and for harvesting energy through coupling with external power sources. This efficient wireless functionality can be important for body area network technologies and can enable operation without the weight and bulky size of batteries for power supply. Recently, antenna designs have received increased attention because their mechanical and electromagnetic properties significantly influence the wireless performance of bio-integrated electronics, particularly under excessive mechanical loads. These mechanical factors are critical for skin-integrated electronics during human motion, as complex skin deformations can damage the conductive traces of antennas, such as those used for near-field communication (NFC), leading to yield or fracture and affecting their electromagnetic stability. Serpentine interconnects have been proposed as a geometric alternative to in-plane circular or rectangular spiral antenna designs to improve the elastic stretchability of the metallic traces in NFC antennas and prevent mechanical fractures. Despite the use of serpentine interconnects within the physiologically relevant strain range for skin (<20%), the electromagnetic stability of the antennas decreases. This instability, reflected by shifts in resonance frequency and scattering parameters due to inductance changes, reduces the antennas' wireless power transfer efficiency and readout range. Therefore, maintaining the electromagnetic stability of antennas, specifically NFC antennas, under various mechanical deformations has become a critical challenge in practical wireless skin-integrated applications, such as sensing and physiological monitoring. Here, we establish a new mechanics and electromagnetic scaling law that quantifies the inductance changes under strain in a rectangular-loop serpentine structure typically used for NFC wireless communication in stretchable electronics. We present a systematic analysis of the antenna's geometric parameters, material properties of the antenna and substrate, and the applied strain on the inductance change. Our findings demonstrate that the relative change of inductance is solely influenced by the serpentine structure's width-radius ratio, arc angle, aspect ratio of the NFC antennas, and the applied strain. Additionally, under physiological strain conditions for the skin, the relative change of inductance can be minimized to preserve the NFC antenna's performance and prevent mechanical fracture and electromagnetic stability loss.

许多种类的柔性和可拉伸的生物集成电子系统依赖于机械敏感的电磁元件，例如用于无线通信的各种形式的天线，以及通过与外部电源耦合来收集能量。这种高效的无线功能对于体域网络技术非常重要，并且可以在不需要电池的重量和体积的情况下进行操作。最近，天线设计受到越来越多的关注，因为它们的机械和电磁特性显着影响生物集成电子的无线性能，特别是在过度机械负载下。在人体运动过程中，这些机械因素对于皮肤集成电子产品至关重要，因为复杂的皮肤变形会损坏天线的导电迹，例如用于近场通信(NFC)的天线，导致屈服或断裂，并影响其电磁稳定性。蛇形互连已被提出作为平面内圆形或矩形螺旋天线设计的几何替代方案，以提高NFC天线中金属迹线的弹性拉伸性并防止机械断裂。尽管在皮肤的生理相关应变范围内(<20%)使用蛇形互连，但天线的电磁稳定性下降。这种不稳定性，反映在谐振频率和散射参数的变化，由于电感的变化，降低了天线的无线功率传输效率和读出范围。因此，保持天线，特别是NFC天线在各种机械变形下的电磁稳定性已成为传感和生理监测等实际无线皮肤集成应用中的关键挑战。在这里，我们建立了一个新的力学和电磁标度定律，量化了在可拉伸电子中通常用于NFC无线通信的矩形环路蛇形结构中应变下的电感变化。我们系统地分析了天线的几何参数、天线和衬底的材料特性以及外加应变对电感变化的影响。我们的研究结果表明，电感的相对变化仅受蛇形结构的宽半径比、弧角、NFC天线的长宽比和外加应变的影响。此外，在皮肤生理应变条件下，可以最小化电感的相对变化，以保持NFC天线的性能，防止机械断裂和电磁稳定性损失。

International Journal of Plasticity

A dislocation theory-based model for brittle-to-ductile transition in multi-principal element alloys

Zebin Han, Bin Liu, Qihong Fang, Peter K Liaw, Jia Li

doi:10.1016/j.ijplas.2024.104059

基于位错理论的多主元素合金脆-韧转变模型

Multi-principal element alloys (MPEAs) have drawn great interest due to their superior mechanical properties compared to the conventional alloys. However, it is unclear in these two aspects: i) how to predict the brittle-to-ductile transition temperature (BDTT) and fracture toughness of MPEAs using theory and model; ii) how to quantify the influences of the complicated alloy composition variation and microstructural parameter on the BDTT and fracture toughness of MPEAs. These issues are critical to both the underlying mechanisms and practical engineering applications. Here, we develop a dislocation theory-based model accounting for the modified lattice friction stress model, the composition-dependent strength model, and the critical energy model to determine the BDTT and corresponding fracture toughness in body-centered cubic MPEAs. The calculated yield stress and BDTT of the as-cast MPEA agree well with the experiments. Subsequently, the BDTT and fracture toughness of TiVNbTa-based MPEAs are obtained as a function of the element concentration fluctuation. The effects of microstructure parameters, such as component randomness and short-range ordering described by the standard deviation of the interplaner potential perturbation and short-range correlation length, on the BDTT and fracture toughness are further elucidated. Importantly, a microstructure-based BDT criterion is proposed to evaluate whether MPEA is ductile or brittle at a given temperature. These results are conducive to the development and application of MPEAs in extreme environments.

多主元素合金(mpea)由于其优越的力学性能而受到人们的广泛关注。然而，如何利用理论和模型预测mpea的脆-韧转变温度和断裂韧性，这两个方面还不清楚;ii)如何量化复杂合金成分变化和显微组织参数对mpea的BDTT和断裂韧性的影响。这些问题对于潜在机制和实际工程应用都是至关重要的。本文建立了基于位错理论的修正晶格摩擦应力模型、成分相关强度模型和临界能量模型，以确定体心立方mpea的BDTT和相应的断裂韧性。铸态MPEA的屈服应力和BDTT计算值与试验值吻合较好。随后，得到了基于tivnbta的mpea的BDTT和断裂韧性随元素浓度波动的函数。进一步阐明了由层间势扰动标准差和短程相关长度描述的组分随机性和短程有序等微观结构参数对BDTT和断裂韧性的影响。重要的是，提出了一种基于微观结构的BDT准则来评估MPEA在给定温度下是延性还是脆性。这些结果有利于mpea在极端环境下的开发和应用。

来源：复合材料力学仿真Composites FEM

【新文速递】2024年6月29日复合材料SCI期刊最新文章

今日更新：Composite Structures 1 篇，Composites Part B: Engineering 2 篇，Composites Science and Technology 1 篇Composite StructuresFlexible, lightweight, tunable robotic arms enabled by X-tensegrity inspired structuresXiao-Hui Yue, Xu Yin, Zi-Yan Sun, Long-Yue Liu, Yantao Wang, Guang-Kui Xu, Changyong Cao, Li-Yuan Zhangdoi:10.1016/j.compstruct.2024.118331受 X-tensegrity 结构启发的灵活、轻质、可调机械臂Robotic arms have remarkable applications in diverse fields such as medical rehabilitation, disaster relief, and space exploration. Enhancing their rigidity, load-bearing capacity, and motion simplicity is key to broadening their usage. Utilizing the admirable flexibility and strength of tensegrity structures, made of rigid bars and elastic strings, we introduce a new type of flexible robotic arm. This arm is constructed using a sequence of two-dimensional X-tensegrity inspired modules. Each module comprises two sets of triangular bars linked by three strings, enhancing the arm’s ability to deform and resist impact forces. The joints between modules are stiff, allowing for angular adjustments to create three-dimensional configurations with adjustable stiffness and curvature. Through theoretical analysis, simulations, and experiments, we have shown that this tensegrity-based robotic arm exhibits superior stability, flexibility, and scalability.机械臂在医疗康复、救灾和太空探索等多个领域都有出色的应用。提高机械臂的刚度、承重能力和运动简易性是扩大其应用范围的关键。利用由刚性杆和弹性弦组成的张拉整体结构令人钦佩的柔韧性和强度，我们推出了一种新型柔性机械臂。这种机械臂由一系列二维 X-张拉整体模块构成。每个模块由两组三角形杆组成，并由三根绳索连接，从而增强了机械臂的变形和抗冲击能力。模块之间的连接处具有一定的硬度，可以进行角度调整，从而形成具有可调硬度和曲率的三维结构。通过理论分析、模拟和实验，我们证明了这种基于张力整体的机械臂具有卓越的稳定性、灵活性和可扩展性。Composites Part B: EngineeringUnveiling the microscopic compression failure behavior of mesophase-pitch-based carbon fibers for improving the compressive strength of their polymer compositesNingyuan Zhang, Dong Huang, Huafeng Quan, Chong Ye, Chaoyi Peng, Lei Tao, Shipeng Zhu, Zhen Fan, Kui shi, Feng Qian, Jinshui Liudoi:10.1016/j.compositesb.2024.111658揭示介相沥青基碳纤维的微观压缩失效行为，提高其聚合物复合材料的抗压强度Mesophase-pitch-based carbon fiber (MPCF) reinforced polymer (MPCFRP) composites show great potential for aerospace applications due to their excellent thermal conductivity and dimensional stability. However, the low compressive strength severely limits their application in high load-bearing areas. To address this issue, MPCF-A with a split-radial structure and MPCF-B with a skin-core structure were meticulously prepared by fiber structure regulation. The compression failure behavior of MPCFs at the monofilament and the microregion levels was investigated using the tensile recoil method and in-situ micropillar compression technique. MPCF-A exhibits the failure mode of petal-like lamellar separation due to axial crack penetrating along the (002) crystal plane of graphite layers, with the compressive strength of the core region (391 MPa) being higher than that of the skin region (360 MPa). Conversely, MPCF-B demonstrates a large transverse fracture in the skin region during damage, along with uniform microcracks in the core region. Notably, the compressive strength of the core region (547 MPa) significantly exceeds that of the skin region (456 MPa). Furthermore, the compressive strength of MPCF-B monofilaments (583 MPa) is higher than that of MPCF-A (462 MPa), attributed to factors such as the smaller graphite crystallite size (La = 36.54 nm, Lc = 26.75 nm), lower crystallite orientation (Z = 10.21°, R = 0.25), smaller pore size (Rg = 9.56 nm), and higher amorphous carbon content (g = 69.77%, K = 20.38). Consequently, the compressive strength of MPCFRP-B (232 MPa) is enhanced by 30.3% compared to MPCFRP-A.介相沥青基碳纤维（MPCF）增强聚合物（MPCFRP）复合材料具有优异的导热性和尺寸稳定性，因此在航空航天领域具有巨大的应用潜力。然而，较低的抗压强度严重限制了其在高承载区域的应用。为解决这一问题，我们通过纤维结构调控技术精心制备了具有劈裂径向结构的 MPCF-A 和具有皮芯结构的 MPCF-B。采用拉伸反冲法和原位微柱压缩技术研究了 MPCF 在单丝和微区层面的压缩失效行为。MPCF-A表现出沿石墨层（002）晶面穿透的轴向裂纹导致花瓣状薄片分离的失效模式，芯区的抗压强度（391 兆帕）高于表皮区（360 兆帕）。相反，MPCF-B 在损坏过程中，表皮区域出现大面积横向断裂，同时在核心区域出现均匀的微裂缝。值得注意的是，核心区域的抗压强度（547 兆帕）大大超过了表皮区域的抗压强度（456 兆帕）。此外，MPCF-B 单丝的抗压强度（583 兆帕）高于 MPCF-A（462 兆帕），这归因于较小的石墨结晶尺寸（La = 36.54 nm，Lc = 26.75 nm）、较低的结晶取向（Z = 10.21°，R = 0.25）、较小的孔径（Rg = 9.56 nm）和较高的无定形碳含量（g = 69.77%，K = 20.38）等因素。因此，与 MPCFRP-A 相比，MPCFRP-B 的抗压强度（232 兆帕）提高了 30.3%。Fully bio-based polylactic acid composites based on molecular crosslinking interface engineeringKang Chen, Pengrui Chen, Bei Qi, Xinyu Zhang, Lijun Cao, Ce Sun, Haiyan Tan, Yanhua Zhangdoi:10.1016/j.compositesb.2024.111663 基于分子交联界面工程的全生物基聚乳酸复合材料The key to achieving high-performance plant fiber/polylactic acid (PLA) composites lies in solving the interfacial compatibility issue between the two components. However, current mainstream methods for interfacial modulation often come with energy consumption and environmental concerns. To address this, our study proposed the development of fully bio-based bamboo fiber (BF)/PLA composites based on the principles of non-toxicity, low carbon footprint, and environmental friendliness. In this study, we aimed to construct a molecular-scale multiphase crosslinking network structure in BF/PLA composites. To achieve this, we utilized cyclodextrins (CD) to induce a regularized alignment of PLA molecular chains and employed epoxidized soybean oil (ESO) ring opening reaction to form bonds connecting BF, CD, and PLA molecules. This approach ensured that the composite is fully bio-based while still exhibiting remarkable mechanical properties. The resulting BF/PLA@CD-ESO composites demonstrated impressive bending strength, reaching 108.65 MPa, which was 23.11% higher than that of the BF/PLA composites. Moreover, the tensile strength reached 67.48 MPa, which was 39.06% higher than that of BF/PLA composites. This study provides a convenient, green and sustainable method for preparing PLA-based composites. The resulting composites are expected to be used in disposable tableware, food packaging and environmentally friendly furniture.实现高性能植物纤维/聚乳酸（PLA）复合材料的关键在于解决两种成分之间的界面相容性问题。然而，目前主流的界面调制方法往往伴随着能耗和环境问题。针对这一问题，我们的研究基于无毒、低碳、环保的原则，提出了开发全生物基竹纤维（BF）/聚乳酸（PLA）复合材料的建议。在本研究中，我们的目标是在 BF/PLA 复合材料中构建分子尺度的多相交联网络结构。为此，我们利用环糊精（CD）诱导聚乳酸分子链规整排列，并采用环氧化大豆油（ESO）开环反应形成连接 BF、CD 和聚乳酸分子的键。这种方法确保了复合材料完全以生物为基础，同时仍具有显著的机械性能。所制备的 BF/PLA@CD-ESO 复合材料表现出惊人的抗弯强度，达到 108.65 兆帕，比 BF/PLA 复合材料高出 23.11%。此外，拉伸强度达到 67.48 兆帕，比 BF/PLA 复合材料高出 39.06%。本研究为制备聚乳酸基复合材料提供了一种便捷、绿色和可持续的方法。所制备的复合材料有望用于一次性餐具、食品包装和环保家具。Composites Science and TechnologyFiber bundle deposition model and variable speed printing strategy for in-situ impregnation 3D printing of continuous fiber reinforced thermoplastic compositesZhenzhen Quan, Cheng Liu, Junjie Li, Xiaohong Qin, Jianyong Yudoi:10.1016/j.compscitech.2024.110723 用于连续纤维增强热塑性复合材料原位浸渍三维打印的纤维束沉积模型和变速打印策略In the in-situ impregnation 3D printing of continuous fiber reinforced thermoplastic composites (CFRTPCs) at constant printing speed, in order to pursue higher printing efficiency, a higher speed for printing is adopted generally, which has no effect on the printing of the straight section, but at the same speed of printing at the corner, the printing speed will cause the fiber bundle to deviate from the printing path at the corner, which affects the accurate laying of fiber bundle along the printing path. Obviously, reducing the printing speed is an effective method to improve the print quality at the turn, but printing the entire part at the reduced speed will greatly limit the overall printing speed. However, the problem of different corner angles and shifting points from the straight section of high-speed printing to the corner section of low-speed printing has been puzzling researchers. In this paper, a fiber bundle deposition model has been proposed to reveal the deposition of fiber bundles, and the maximum offsets of fiber bundles were predicted under different turning angles. Compared with the measured results, the prediction error at different turning angles ranged from -1.07% to 10.30%. Then, combining with the finite element analysis method, the fiber bundle deposition model was adopted to study the effects of printing speeds, and the maximum printing speeds for different printing angles and the variable printing speed strategy have been put forward. The results have revealed that, by using the optimized variable printing speed strategy, the surface quality of the fabricated parts and the deposition of the fiber bundles along the designed printing path were significantly improved. The fiber bundle deposition model and the variable speed printing strategy could be helpful for the high-precision 3D printing of CFRTPCs.在匀速原位浸渍三维打印连续纤维增强热塑性复合材料（CFRTPC）时，为了追求更高的打印效率，一般采用较高的打印速度，这对直线部分的打印没有影响，但在转角处以同样的速度打印时，打印速度会使纤维束在转角处偏离打印路径，影响纤维束沿打印路径的准确铺设。显然，降低印刷速度是提高转角处印刷质量的有效方法，但以降低的速度印刷整个部件会大大限制整体印刷速度。然而，从高速印刷的直线段到低速印刷的转角段，转角角度和移位点不同的问题一直困扰着研究人员。本文提出了一种纤维束沉积模型来揭示纤维束的沉积，并预测了不同转角下纤维束的最大偏移量。与实测结果相比，不同转角下的预测误差在-1.07%到10.30%之间。然后，结合有限元分析方法，采用纤维束沉积模型研究了印刷速度的影响，提出了不同印刷角度下的最大印刷速度和变速印刷策略。结果表明，通过采用优化的变速印刷策略，制件的表面质量和纤维束在设计印刷路径上的沉积情况都得到了显著改善。纤维束沉积模型和变速打印策略有助于 CFRTPC 的高精度三维打印。来源：复合材料力学仿真Composites FEM