【新文速递】2024年2月28日复合材料SCI期刊最新文章

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今日更新：Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 2 篇

Composites Part A: Applied Science and Manufacturing

Promoting bridging in adhesively bonded composites with polymer inserts: A computational perspective

Ditho Pulungan, Sofyan Andika, Tatacipta Dirgantara, Riza Wirawan, Hermawan Judawisastra, Satrio Wicaksono

doi:10.1016/j.compositesa.2024.108107

用聚合物插入物促进粘合复合材料中的桥接：计算视角

Preventing catastrophic failure due to delamination in adhesively bonded carbon fiber reinforced polymer (CFRP) is crucial to enhancing the reliability of structures. Experimental evidence from another study demonstrated that introducing inserts into the adhesive bond line creates bridging, effectively arresting the delamination process. In this paper, a numerical model was proposed to mimic the experiment and then utilized for conducting parametric studies. An embedded cell approach was adopted, representing a double cantilever beam (DCB) with linear-elastic continuum shell elements, beam elements for the bridging bundles, and connector elements for the adhesive. The crack propagation was initiated with adhesive failure and subsequently followed by bridging bundle failure. The numerical simulation results closely replicated the experiment’s global response in the force–displacement curve, thereby effectively validating the existence of the bridging effect. Furthermore, our study revealed that enhancing the adhesive strength and insert ductility can further improve crack resistance.

防止因粘合碳纤维增强聚合物（CFRP）分层而导致的灾难性失效对于提高结构的可靠性至关重要。另一项研究的实验证据表明，在粘合剂粘合线中引入插入物可产生桥接，有效阻止分层过程。本文提出了一个数值模型来模拟实验，然后利用该模型进行参数研究。该模型采用嵌入式单元方法，用线性弹性连续壳元素表示双悬臂梁 (DCB)，用梁元素表示桥接束，用连接器元素表示粘合剂。裂纹扩展始于粘合剂失效，随后桥接束失效。数值模拟结果与实验中力-位移曲线的全局响应密切相关，从而有效验证了桥接效应的存在。此外，我们的研究还发现，提高粘合强度和插入延展性可进一步改善抗裂性。

Composites Part B: Engineering

4D printed multifunctional wearable strain sensors with programmable sensing characteristics

Jifeng Zhang, Xue Yang, Wangxuan Li, Hongpei Liu, Zhifu Yin, Yangbo Chen, Xueli Zhou

doi:10.1016/j.compositesb.2024.111346

具有可编程传感特性的 4D 印刷多功能可穿戴应变传感器

Combining 4D-printed bilayer actuators with the slit structure and sensing capabilities unique to the process further promotes the use of 4D printing in biomedical devices, human-computer interaction, intelligent self-protection devices, and humanoid robots. In this study, we propose an adaptive multifunctional strain sensor (AMSS) 4D printing strategy based on the shape memory properties of polylactic acid (PLA), a bioslit structural sensing unit, and a bi-directional deformation design of a bilayer structure. The obtained AMSS was shown to have excellence sensitivity to strain, mechanical, and temperature stimuli. In particular, thanks to the 3D printed slit structure and phase transition properties of the PLA printing layer, the AMSS macro-microstructure can be precisely tuned, and its sensing performance is shown to be intelligently programmable. The built-in structural design-induced macro-deformation enables AMSS to adaptively fit human joint surfaces for full-range human motion recognition. In addition, the close correlation of strain-sensing during AMSS shape transformation enables position self-sensing and strain self-sensing of AMSS. Further, through the integration and separation of resistive signals, we are able to recognize temperature and mechanical stimuli. Finally, we integrate the wireless sensing module into the AMSS to improve the portability and wearability of the sensor.

将 4D 印刷双层致动器与该工艺特有的缝隙结构和传感功能相结合，可进一步促进 4D 印刷在生物医学设备、人机交互、智能自我保护设备和仿人机器人中的应用。在这项研究中，我们基于聚乳酸（PLA）的形状记忆特性、生物光结构传感单元和双层结构的双向变形设计，提出了一种自适应多功能应变传感器（AMSS）4D 打印策略。结果表明，获得的 AMSS 对应变、机械和温度刺激具有卓越的灵敏度。特别是，得益于三维打印狭缝结构和聚乳酸打印层的相变特性，AMSS 的宏观微观结构可以被精确调整，其传感性能被证明是智能可编程的。内置结构设计引起的宏观变形使 AMSS 能够自适应地贴合人体关节表面，从而实现全方位的人体运动识别。此外，AMSS 形状变换过程中的应变感应密切相关，实现了 AMSS 的位置自感应和应变自感应。此外，通过整合和分离电阻信号，我们还能识别温度和机械刺激。最后，我们将无线传感模块集成到 AMSS 中，以提高传感器的便携性和可穿戴性。

A continuum damage model for Mg/Al composite sheets rolling: Theoretical development and application

Tao Wang, Chenchen Zhao, Gang Zhang, Wenqiang Zhao, Qingxue Huang

doi:10.1016/j.compositesb.2024.111347

镁铝复合材料板材轧制连续损伤模型：理论发展与应用

Edge cracks, which are typical formability defects, severely limit the widespread application of Mg/Al composite sheets. Accurate prediction of damage is crucial for understanding the underlying mechanisms behind crack formation. In this study, a continuum damage model that incorporates the stress-state function and effective equivalent plastic strain into the standard Lemaitre model is proposed. This enhanced model effectively addresses the issues of damage-evolution linearization and tension–compression asymmetry in the standard Lemaitre model. Thus, it can be successfully applied to predict the fracture response of ductile composite materials under pressure-forming conditions. Considering AZ31B Mg alloy and 5052 Al alloy as experimental materials, physical experiments and numerical validation are performed under a 50% reduction and 350 °C. The findings show that the proposed model effectively captures crack initiation and propagation during the rolling process, with errors of only 23.1% and 19.9% for average crack quantity and length, respectively. Results of numerical analysis reveals that the high-stress triaxiality at the edge of the sheet contributes significantly to crack formation. Additionally, the strain along the normal direction in the Al alloy significantly affects crack propagation and the formation of serrated cracks on the side of Mg alloy. This study provides important theoretical foundations for the development of Mg-based composite sheets.

边缘裂纹是典型的成型缺陷，严重限制了镁/铝复合材料板材的广泛应用。准确预测损伤对于理解裂纹形成背后的基本机制至关重要。本研究提出了一种将应力状态函数和有效等效塑性应变纳入标准勒梅特模型的连续损伤模型。这种增强型模型有效地解决了标准 Lemaitre 模型中损伤演变线性化和拉伸-压缩不对称的问题。因此，该模型可成功用于预测压力成型条件下韧性复合材料的断裂响应。以 AZ31B Mg 合金和 5052 Al 合金为实验材料，在减薄 50%、温度为 350 ℃ 的条件下进行了物理实验和数值验证。结果表明，所提出的模型能有效捕捉轧制过程中裂纹的产生和扩展，平均裂纹数量和长度的误差分别仅为 23.1% 和 19.9%。数值分析结果表明，板材边缘的高应力三轴性在很大程度上导致了裂纹的形成。此外，铝合金沿法线方向的应变也对裂纹扩展和镁合金侧面锯齿状裂纹的形成产生了重要影响。这项研究为镁基复合材料板材的开发提供了重要的理论基础。

来源：复合材料力学仿真Composites FEM

【新文速递】2024年3月2日复合材料SCI期刊最新文章

今日更新：Composite Structures 2 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 1 篇Composite StructuresDesign and performance simulation of hybrid hemp/glass fiber composites for automotive front bumper beamsNapat Nawawithan, Peerapat Kittisakpairach, Supakit Nithiboonyapun, Kitchanon Ruangjirakit, Pattaramon Jongpradistdoi:10.1016/j.compstruct.2024.118003用于汽车前保险杠横梁的混合麻/玻璃纤维复合材料的设计与性能模拟This study investigates the use of hemp/glass fiber reinforced epoxy composites for designing automotive front bumper beams, focusing on crashworthiness and pedestrian safety. The composite bumper beam model is evaluated through low- and high-velocity crash simulations and pedestrian leg form impact tests using LS-DYNA software. Optimal stacking sequences are analyzed, with high-strength glass fibers positioned on the outer layers to bear impact loads and low-density hemp fibers in the middle. The hybrid hemp (H)/glass (G) fiber composite laminate can absorb up to 90 % of the impact energy absorbed by a glass fiber composite, with a ± 45° fiber orientation, showing exceptional energy absorption capabilities. The [G(±45°)4, H(±45°)4]S composite bumper beam offers superior impact performance, safety, and a weight reduction of 49.2 % compared to a commercial steel bumper beam. This study highlights the potential of natural fiber composites as sustainable alternatives in automotive design.本研究调查了麻/玻璃纤维增强环氧树脂复合材料在汽车前保险杠横梁设计中的应用，重点关注耐撞性和行人安全。通过低速和高速碰撞模拟以及使用 LS-DYNA 软件进行的行人腿部冲击测试，对复合材料保险杠横梁模型进行了评估。对最佳堆叠顺序进行了分析，高强度玻璃纤维位于外层以承受冲击载荷，低密度麻纤维位于中间。混合麻（H）/玻璃（G）纤维复合层压板吸收的冲击能量可达玻璃纤维复合材料的 90%，纤维取向为 ±45°，显示出卓越的能量吸收能力。G（±45°）4，H（±45°）4]S 复合材料保险杠横梁具有卓越的冲击性能和安全性，与商用钢保险杠横梁相比，重量减轻了 49.2%。这项研究凸显了天然纤维复合材料作为汽车设计中可持续替代品的潜力。Composites Part B: EngineeringThermomechanical characterisation of reprocessable, siloxane-based, glass-fibre-reinforced vitrimersVirginia Amfilochiou, Tapas Debsharma, Ives De Baere, Lode Daelemans, Filip Du Prez, Wim Van Paepegemdoi:10.1016/j.compositesb.2024.111354硅氧烷基玻璃纤维增强型可再加工玻璃纤维的热力学特性分析Polymer composites have been extensively used for the last 30 years in the automotive, green-energy, maritime and aerospace industries. While the demands of composites' applications are increasing, complications are arising regarding their sustainability. In this work, a siloxane-based vitrimer with fast stress-relaxation, and its Glass-Fibre-Reinforced Vitrimer (GFRV) were manufactured and mechanically characterised as a sustainable alternative to thermoset composites produced by infusion. Dynamic mechanical analysis and differential scanning calorimetry were performed to identify the ageing effect on the glass-transition temperature of the materials. Tensile and in-plane shear tests were executed to investigate the materials’ performance at elevated temperature. The results were compared to the ones of a thermoset benchmark and showed that after ageing and up to 50 °C, both the neat vitrimer and its corresponding composite exhibited a thermomechanical performance comparable to their thermoset counterparts. GFRV specimens were then successfully reprocessed by hot-pressing up to two consecutive cycles. The GFRV specimen was thermoformed into an omega-stiffener profile by the first hot-pressing cycle, while its flat profile was restored during the second cycle. Finally, the reprocessing results were evaluated by optical microscopy, demonstrating that the newly developed advanced GFRV is indeed a viable, sustainable alternative.过去 30 年来，聚合物复合材料已广泛应用于汽车、绿色能源、航海和航空航天等行业。在复合材料应用需求不断增长的同时，复合材料的可持续发展问题也日益复杂。在这项研究中，我们制造了一种具有快速应力松弛功能的硅氧烷基玻璃聚合物及其玻璃纤维增强玻璃聚合物（GFRV），并对其进行了机械性能表征，以作为通过导流生产的热固性复合材料的可持续替代品。通过动态机械分析和差示扫描量热法确定了老化对材料玻璃化转变温度的影响。为了研究材料在高温下的性能，还进行了拉伸和平面剪切试验。测试结果与热固性材料的测试结果进行了比较，结果表明，经过高达 50 ° C 的老化后，纯玻璃聚合物及其相应复合材料的热机械性能与热固性材料相当。随后，GFRV 试样通过连续两个循环的热压成功地进行了再加工。在第一个热压循环中，GFRV 试样被热成型为欧米茄加固轮廓，而在第二个循环中，其扁平轮廓得以恢复。最后，通过光学显微镜对再加工结果进行了评估，证明新开发的先进 GFRV 确实是一种可行的、可持续的替代品。Composites Science and TechnologyHigh-efficiency electromagnetic wave absorption of lightweight Nb2O5/CNTs/polyimide with excellent thermal insulation and compression resistance integrationYuanyuan Zeng, Lan Long, Jiaqi Yu, Yuqi Li, Yang Li, Wei Zhoudoi:10.1016/j.compscitech.2024.110531 轻质 Nb2O5/CNTs/ 聚酰亚胺的高效电磁波吸收技术，具有优异的隔热性和抗压性一体化性能With the widespread application of electronic devices, multifunctional electromagnetic wave (EMW) absorbing materials suitable for complex high-temperature and high-pressure environments, have attracted tremendous research attention. Herein, multifunctional polyimide (PI) composites doped with fluffy Nb2O5/CNTs microspheres (NBCP) were prepared by combining the ultrasonic spraying process and freeze-drying technique. Introduction of fillers results in the formation of diverse conduction paths and heterogeneous interfaces, which enhance the dielectric loss. Furthermore, the multi-porous structure of the PI matrix induces multiple reflection scattering events and improves the impedance matching. Such a multi-loss mechanism endows NBCP with an excellent EMW absorption performance. At 15 vol% filling, the minimum reflection loss is −41.66 dB, the effective absorption bandwidth is 2.63 GHz, and the radar cross-section is reduced by 85%. Furthermore, NBCP exhibits outstanding mechanical properties and a thermal insulation of over 100 °C in thermal environment at 150 °C. The proposed multifunctional NBCP is thus an efficient EMW absorber that offers significant potential for applications in harsh environments.随着电子设备的广泛应用，适用于复杂高温高压环境的多功能电磁波（EMW）吸收材料引起了人们的极大关注。本文结合超声喷涂工艺和冷冻干燥技术，制备了掺杂绒毛状 Nb2O5/CNTs 微球（NBCP）的多功能聚酰亚胺（PI）复合材料。填料的引入导致形成了不同的传导路径和异质界面，从而提高了介电损耗。此外，PI 基体的多孔结构还诱导了多重反射散射事件，改善了阻抗匹配。这种多重损耗机制赋予了 NBCP 极佳的电磁波吸收性能。当填充量为 15 vol% 时，最小反射损耗为 -41.66 dB，有效吸收带宽为 2.63 GHz，雷达截面减少了 85%。此外，NBCP 还具有出色的机械性能，在 150 °C 的热环境中隔热性能超过 100 °C。因此，所提出的多功能 NBCP 是一种高效的电磁波吸收器，在恶劣环境中的应用潜力巨大。来源：复合材料力学仿真Composites FEM