【新文速递】2024年3月20日固体力学SCI期刊最新文章

今日更新：Composite Structures 5 篇，Composites Part A: Applied Science and Manufacturing 3 篇Composite StructuresThermoelastic diffusion in nonlocal orthotropic medium with porosityAbhishek Mallick, Siddhartha Biswasdoi:10.1016/j.compstruct.2024.118043有孔隙率的非局部正交介质中的热弹性扩散The present article investigates the linear theory of nonlocal thermoelasticity in homogeneous orthotropic porous medium with diffusion in the context of dual-phase-lag model. The focal point of the present study involves an examination of Fick’s mass diffusion law and the generalized Fourier’s law within the context of the dual-phase-lag model of hyperbolic thermoelasticity. The incorporation of voids, mass diffusion with phase lagging in the diffusion flux is the basis for establishing the void diffusion-elasticity models. Furthermore, the new dual-phase-lag diffusion model introduces the consideration of nonlocal effects in mass transfer. The resolution of the problem involves the utilization of normal mode analysis, employed for solving, and encompasses the application of thermal shock at the surface boundary. Numerical calculations of stress components, displacement components, voids, temperature, and concentration of the diffusive material are performed for various distances and time intervals.本文以双相位滞后模型为背景，研究了均质各向同性多孔介质中具有扩散的非局部热弹性线性理论。本研究的重点是在双相滞后双曲热弹性模型的背景下研究菲克质量扩散定律和广义傅里叶定律。在扩散通量中加入空隙、相滞后的质量扩散是建立空隙扩散弹性模型的基础。此外，新的双相滞后扩散模型还引入了对传质非局部效应的考虑。问题的解决涉及利用法向模态分析进行求解，包括在表面边界施加热冲击。在不同距离和时间间隔内，对扩散材料的应力分量、位移分量、空隙、温度和浓度进行了数值计算。Influencing mechanism on sensitivity of carbonized fabric strain sensors and modification of bridge-connection model: Comparison of three silk woven structuresShilin Liu, Wenting Zhang, Jingzong He, Yonggen Lu, Bin Sun, Qilin Wu, Malcolm Xingdoi:10.1016/j.compstruct.2024.118041 碳化织物应变传感器灵敏度的影响机理及对桥接模型的修正三种丝织结构的比较Given the great potential of carbonized fabric strain sensors in wearable devices, carbonized silk fabrics (CSF) with three characteristic woven structures including georgette (CSF-g), crepe de chine (CSF-c) and crepe satin plain (CSF-p) were employed to investigate the dependence of gauge factor (GF) on two critical parameters: initial resistance (R0) and resistance change (ΔR). The results showed that increasing carbonization temperature can effectively reduce R0 and increase GF of CSF-g, but has little effect on CSF-c and CSF-p. It was further found that the GF of both CSF-c and CSF-p were dominated by ΔR related to the crack propagation path, i.e. high sensitivity CSF was typically accompanied by dense “islands” and fine gaps, while low sensitivity CSF was accompanied by wide cracks and sparse “islands”. Accordingly, a modified bridge connection model was proposed to elucidate the relationship between crack morphology and resistance variation. This model successfully achieved continuous exponential fitting of resistance with admirable fitting goodness. Finally, the prepared sensor exhibited an ultra-high GF (916.5) and was well applied in health monitoring and thermal treatment. These efforts put forward guidance to the design and fabrication of ultrasensitive CSF strain sensors.鉴于碳化织物应变传感器在可穿戴设备中的巨大潜力，我们采用了三种特征编织结构的碳化丝织物（CSF），包括乔其纱（CSF-g）、绉绸（CSF-c）和绉缎平纹布（CSF-p），研究了计测因子（GF）对两个关键参数的依赖性：初始电阻（R0）和电阻变化（ΔR）。结果表明，提高碳化温度可有效降低 R0 并提高 CSF-g 的 GF，但对 CSF-c 和 CSF-p 影响不大。研究还发现，CSF-c 和 CSF-p 的 GF 受与裂纹扩展路径相关的 ΔR 的支配，即高灵敏度 CSF 通常伴随着密集的 "孤岛 "和细小的间隙，而低灵敏度 CSF 则伴随着宽大的裂纹和稀疏的 "孤岛"。因此，我们提出了一个改进的桥梁连接模型，以阐明裂纹形态与电阻变化之间的关系。该模型成功地实现了电阻的连续指数拟合，拟合效果令人满意。最后，制备的传感器显示出超高的 GF 值（916.5），并在健康监测和热处理中得到了很好的应用。这些工作为设计和制造超灵敏 CSF 应变传感器提供了指导。Mechanical behavior of interpenetrating phase composite structures based on triply periodic minimal surface latticesKedi Wang, Han Wang, Jiaqi Zhang, Xueling Fandoi:10.1016/j.compstruct.2024.118044基于三重周期性最小表面晶格的互穿相复合结构的力学行为The triple periodic minimal surface (TPMS) structures have received widespread attention due to their excellent mechanical properties, such as high specific strength and energy absorption. However, these structures are prone to suffering catastrophic damage due to stress concentration and shear deformation in actual loading environments, affecting their load-bearing performance. In this work, interpenetrating phase composite (IPC) structures were fabricated by filling thermoplastic polyurethane (TPU) as a soft material into the diamond minimal surface structure using the multi-material fused deposition modeling technique, and their mechanical behavior was investigated numerically and experimentally. The effects of topological types and volume fractions on the performance of IPC structures were investigated. It is shown that the IPC structure undergoes stretching-dominated deformation, and its strength and toughness are significantly improved compared to the TPMS structure. Due to the addition of a complementary phase structure made of TPU, stress concentration and shear failure are reduced. The global deformation of the IPC structure and stress distribution of the TPMS phase are more uniform, effectively protecting the entire structure from catastrophic failure.三重周期性最小表面（TPMS）结构因其出色的机械性能（如高比强度和能量吸收）而受到广泛关注。然而，这些结构在实际加载环境中容易因应力集中和剪切变形而遭受灾难性破坏，影响其承载性能。本研究采用多材料熔融沉积建模技术，将热塑性聚氨酯（TPU）作为软材料填充到金刚石最小表面结构中，制备了互穿相复合材料（IPC）结构，并对其力学行为进行了数值和实验研究。研究了拓扑类型和体积分数对 IPC 结构性能的影响。结果表明，与 TPMS 结构相比，IPC 结构发生了以拉伸为主的变形，其强度和韧性得到了显著提高。由于添加了由热塑性聚氨酯制成的互补相结构，应力集中和剪切破坏现象有所减少。IPC 结构的整体变形和 TPMS 相的应力分布更加均匀，有效地保护了整个结构免受灾难性破坏。Strength models of near-surface mounted (NSM) fibre-reinforced polymer (FRP) shear-strengthened RC beams based on machine learning approachesY. Ke, S.S. Zhang, M.J. Jedrzejko, G. Lin, W.G. Li, X.F. Niedoi:10.1016/j.compstruct.2024.118045基于机器学习方法的近表面安装 (NSM) 纤维增强聚合物 (FRP) 抗剪加固 RC 梁强度模型The shear strengthening of reinforced concrete (RC) beams using near-surface mounted (NSM) fibre-reinforced polymer (FRP) bars/strips has gained substantial research attention worldwide. However, owing to the complex failure mechanisms and many influencing parameters, the shear capacities of NSM FRP shear-strengthened beams are difficult to predict. Accordingly, this study adopted machine learning approaches to predict the shear capacity of strengthened beams. An experimental database was constructed comprising 130 rectangular/T-shaped beams and their 15 parameters, collected from the existing literature. Subsequently, a genetic-algorithm-improved back propagation neural network (GA-BPNN) trained with a Bayesian regularisation (BR) algorithm was employed, which was capable of giving accurate predictions on shear capacities of strengthened beams and own good generalisation ability. Furthermore, the GA-BPNN was used for parametric studies to investigate the parameter effects on the contributions of concrete, steel stirrups, and NSM FRP to the shear capacity. Finally, with reference to the GA-BPNN parametric analyses and existing models, a design-oriented strength model for calculating the shear capacities of NSM FRP shear-strengthened beams was proposed and optimised using the genetic algorithm. A comparison with existing models proved the higher prediction accuracy of the proposed strength model.使用近表面贴装（NSM）纤维增强聚合物（FRP）条/带对钢筋混凝土（RC）梁进行剪切加固的研究在全球范围内获得了极大的关注。然而，由于复杂的破坏机制和众多的影响参数，NSM FRP 剪力加固梁的抗剪能力很难预测。因此，本研究采用机器学习方法来预测加固梁的抗剪承载力。从现有文献中收集了 130 个矩形/T 形梁及其 15 个参数，构建了一个实验数据库。随后，采用贝叶斯正则化（BR）算法训练的遗传算法改进反向传播神经网络（GA-BPNN），能够准确预测加固梁的抗剪承载力，并具有良好的泛化能力。此外，GA-BPNN 还用于参数研究，以调查参数对混凝土、钢箍筋和 NSM FRP 对剪切能力贡献的影响。最后，参考 GA-BPNN 参数分析和现有模型，提出了一个以设计为导向的强度模型，用于计算 NSM FRP 剪力加固梁的抗剪承载力，并使用遗传算法进行了优化。与现有模型的比较证明，所提出的强度模型具有更高的预测精度。Quasi-periodic sonic black hole with low-frequency acoustic and elastic bandgapsHui Sheng, Meng-Xin He, Heow Pueh Lee, Qian Dingdoi:10.1016/j.compstruct.2024.118046具有低频声带隙和弹性带隙的准周期声波黑洞Metamaterials with the capability to control wave propagation in fluid or solid mediums have attracted plenty of fundamental scientific and engineering research in recent decades. This paper proposes a novel metamaterial, named Quasi-periodic sonic black hole (Q-SBH), to achieve both acoustic bandgap and elastic bandgap. The Q-SHB consists of two functional units: outer soft shells and inner stiff rings. The stiff rings with decaying inner radii are connected by soft shells, and the distances between rings take linear variation. The Q-SBH reserves the slow-sound effect of sonic black hole and the non-uniformly distributed rings serve as mistuning vibration absorbers. On the basis of these characteristics, broadband low-frequency acoustic and elastic bandgaps are generated simultaneously. We demonstrate the attenuation performance of the Q-SBH by theoretical, numerical and experimental methods. Parametric analysis and multi-objective optimization of the structure are carried out. The results demonstrate the great potential of the proposed Q-SBH in a broad range of physical fields requiring both air-borne noise reduction and structural vibration suppression.近几十年来，能够控制波在流体或固体介质中传播的超材料吸引了大量基础科学和工程研究。本文提出了一种新型超材料，名为准周期声波黑洞（Quasi-periodic sonic black hole，Q-SBH），可同时实现声带隙和弹性带隙。Q-SHB 由两个功能单元组成：外部软壳和内部硬环。内半径逐渐减小的硬环由软壳连接，硬环之间的距离呈线性变化。Q-SBH 保留了声波黑洞的慢声效应，而非均匀分布的环则起到了失谐吸振的作用。在这些特性的基础上，同时产生了宽带低频声带隙和弹性带隙。我们通过理论、数值和实验方法证明了 Q-SBH 的衰减性能。我们还对该结构进行了参数分析和多目标优化。结果表明，所提出的 Q-SBH 在需要降低气载噪声和抑制结构振动的广泛物理领域具有巨大潜力。Composites Part A: Applied Science and ManufacturingX-ray microtomography observation of interfacial debonding in CFRP under combined loadingYi Zhou, Ying Wang, Zheng-Ming Huang, Jian-Xiu Wang, Yan Lidoi:10.1016/j.compositesa.2024.108160联合加载下 CFRP 的界面脱粘 X 射线显微层析观察One of the remaining challenges for advancing the theoretical mechanics of composite materials is to describe the relationship between interfacial debonding and the mechanical properties of composites. The fiber/matrix interfacial debonding of model composites caused by combined loading has been observed by in-situ X-ray radiography and post-mortem X-ray computed tomography (CT) in this paper. Off-axis tension (fiber axis lying at 30°, 45°, 60° or 90° with respect to the loading direction) tests have been performed on carbon fiber reinforced polymer (CFRP) cruciform specimens using an in-situ loading rig. The morphological characteristics of the cracks at the interface and in the matrix are recorded. Based on our observations, the difference between interfacial debonding caused by normal tension and tangential shear stresses and their cooperative actions in composites under combined loading have been studied. This research can give insights into interfacial debonding in composites and help to build an accurate micro-mechanical model.如何描述复合材料界面脱落与复合材料力学性能之间的关系，是推进复合材料理论力学研究的挑战之一。本文通过原位 X 射线射线照相术和死后 X 射线计算机断层扫描（CT）观察了复合材料模型在联合加载作用下产生的纤维/基体界面脱粘现象。使用原位加载装置对碳纤维增强聚合物（CFRP）十字形试样进行了离轴拉伸（纤维轴与加载方向成 30°、45°、60° 或 90°）试验。记录了界面和基体中裂纹的形态特征。根据我们的观察结果，研究了复合材料在联合加载条件下，由法向拉应力和切向剪应力引起的界面脱粘之间的差异及其协同作用。这项研究有助于深入了解复合材料中的界面脱粘现象，并有助于建立精确的微观力学模型。Phase change composites with ultra-high through-plane thermal conductivity achieved by vertically-aligned graphite film and double-shelled microcapsulesLei Kang, Hongyu Niu, Liucheng Ren, Ruicong Lv, Shulin Baidoi:10.1016/j.compositesa.2024.108162 通过垂直排列的石墨薄膜和双壳微胶囊实现具有超高通面热导率的相变复合材料The heat dissipation in electronic devices has become bottleneck problem. One of the best solutions is to develop high performance materials which can not only dissipate the heat away, but also absorb heat energy. This kind of double function materials can be obtained by simultaneously using high thermal conductivity (TC) materials and phase change materials. The formation of continuous network of thermally conductive fillers is demonstrated as one of the most effective methods for fabricating highly thermally conductive composites. Here, graphite films (GF) are stacked and vertically cut to endow the composites with high through-plane TC. The obtained composites exhibit a through-plane TC of 51.55 W m−1 K−1 and a low thermal resistance of 0.398 °C cm2 W−1. Besides, double-shelled PDA@SiO2@paraffin (Pa) microcapsules are embedded into the composite to give its good heat-absorption capacity. Via a CPU thermal stress test, the composites demonstrate satisfactory temperature controlling performance.电子设备的散热已成为瓶颈问题。最好的解决方案之一就是开发既能散热又能吸收热能的高性能材料。通过同时使用高导热（TC）材料和相变材料，可以获得这种双功能材料。导热填料连续网络的形成被证明是制造高导热复合材料的最有效方法之一。在这里，将石墨薄膜（GF）堆叠并垂直切割，使复合材料具有较高的通面导热系数。所获得的复合材料具有 51.55 W m-1 K-1 的通面热导率和 0.398 °C cm2 W-1 的低热阻。此外，复合材料中还嵌入了双壳 PDA@SiO2@paraffin (Pa) 微胶囊，使其具有良好的吸热能力。通过中央处理器热应力测试，复合材料显示出令人满意的温度控制性能。Porous nanofibers and micro-pyramid structures array for high-performance flexible pressure sensorsTao Wang, Xue Shang, Hu Wang, Jilai Wang, Chengpeng Zhangdoi:10.1016/j.compositesa.2024.108163 用于高性能柔性压力传感器的多孔纳米纤维和微金字塔结构阵列Flexible pressure sensors have attracted extensive research interest as smart wearable devices’ core components. However, developing flexible pressure sensors with high sensitivity and wide pressure detection range remains a great challenge. Utilizing electrospinning and mould transfer technology, this paper presents a novel ‘sandwich’ flexible pressure sensor composed of a sensitive layer of poly (lactic acid) (PLA) porous nanofiber network film and electrodes made of polydimethylsiloxane (PDMS) micro-pyramid structure array film. Through ultrasonic treatment, carbon black particles penetrate into the PLA porous nanofiber film, which effectively enhances the conductivity of the PLA film. Due to the complex conductive pathways formed by the ultra-high specific surface area of the PLA porous nanofibers and the three-dimensional amplification structure of the PDMS micro-pyramid arrays, the sensor has a high sensitivity of 54.06 kPa−1, a wide detection range of 0–56 kPa, an ultra-low detection limit of 2.5 Pa and excellent durability (10000 cycles). Impressively, the sensor is able to accurately monitor various physiological activities of the human body in real time, which is believed to be a strong impetus for the development of the next generation of wearable products.柔性压力传感器作为智能可穿戴设备的核心部件，已经引起了广泛的研究兴趣。然而，开发具有高灵敏度和宽压力检测范围的柔性压力传感器仍然是一项巨大的挑战。本文利用电纺丝和模塑转移技术，提出了一种新型 "三明治 "柔性压力传感器，由聚乳酸（PLA）多孔纳米纤维网络薄膜敏感层和聚二甲基硅氧烷（PDMS）微金字塔结构阵列薄膜电极组成。通过超声波处理，炭黑颗粒渗入聚乳酸多孔纳米纤维薄膜，从而有效增强了聚乳酸薄膜的导电性。由于聚乳酸多孔纳米纤维的超高比表面积和 PDMS 微金字塔阵列的三维放大结构形成了复杂的导电通路，该传感器具有 54.06 kPa-1 的高灵敏度、0-56 kPa 的宽检测范围、2.5 Pa 的超低检测限和出色的耐用性（10000 次循环）。令人印象深刻的是，该传感器能够实时准确地监测人体的各种生理活动，相信这将有力地推动下一代可穿戴产品的开发。来源：复合材料力学仿真Composites FEM