今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 3 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
A high performance piezoelectric hetero-junction based on the configuration reform on interfacial potential barrier
Yang Wanli, Hong Renzhong, Yang Haozhen, Hu Yuantai
doi:10.1016/j.compstruct.2023.117723
基于界面势垒构型改革的高性能压电异质结
In this paper, the barrier region of a mixed hetero-junction consisting of a p-type Si and an n-type ZnO was fully opened by abandoning the depletion layer approximation in advance. The barrier configuration was reconstructed by the artificial potential barrier based on a new fully coupled model in which the interaction between physical fields and charge carriers was taken into account. Then, we put forward an interesting design idea of elevating the mechanical regulation performance of a PN junction by manufacturing it with a third-generation piezoelectric semiconductor and a narrow bandgap semiconductor. It is through the deformation of the third-generation piezoelectric semiconductor on one side under mechanical loadings to excite polarization charges at the PN interface such that the movement of charge carriers in the narrow bandgap semiconductor on the other side is able to be tuned by the interface polarization charges. Besides, it is found a specific current-stress characteristic for such a mixed hetero-junction, which will present three stages, i.e., rising stage, platform stage and falling stage. The rising stage is caused by the improving recombination rate, which can be used as a high sensitivity stress sensor (output current improved by more than 10 times in a small stress). Oppositely, the falling stage is caused by the weakened recombination rate due to carrier type-inversion, which can be used to determine overload (output current reduced dramatically when the stress increased to a specific value). Finally, the platform stage is caused by the competition of the above two cases. At this stage, the device operates very stable and can resist the external perturbation. Obviously, the study possesses referential significance to the design and mechanical tuning on performance of piezotronic devices.
本文通过提前放弃耗尽层近似,完全打开了由 p 型硅和 n 型氧化锌组成的混合异质结的势垒区。在考虑物理场与电荷载流子相互作用的新的全耦合模型基础上,通过人工势垒重建了势垒构型。然后,我们提出了一个有趣的设计思路,即通过使用第三代压电半导体和窄带隙半导体制造 PN 结,提高其机械调节性能。在机械负载作用下,一侧的第三代压电半导体会发生形变,从而激发 PN 接口的极化电荷,这样,另一侧窄带隙半导体中的电荷载流子运动就能受到接口极化电荷的调节。此外,还发现了这种混合异质结的特定电流应力特性,它将呈现三个阶段,即上升阶段、平台阶段和下降阶段。上升阶段由不断提高的重组率引起,可用作高灵敏度应力传感器(在较小应力下输出电流提高 10 倍以上)。相反,下降阶段是由载流子类型转换导致的重组率减弱引起的,可用于判断过载(当应力增加到特定值时,输出电流急剧下降)。最后,平台阶段是由上述两种情况的竞争造成的。在这一阶段,设备运行非常稳定,可以抵御外部扰动。显然,该研究对压电器件性能的设计和机械调整具有参考意义。
Resistance-welded thermoset composites: A Bayesian approach to process optimisation for improved fracture toughness
Maierhofer Thomas, Loukaides Evripides G., Carr Craig, Bisagni Chiara, Butler Richard
doi:10.1016/j.compositesa.2023.107894
电阻焊接热固性复合材料:提高断裂韧性的贝叶斯工艺优化方法
Joining thermoset composites via resistance welding offers a novel highly efficient assembly method for next-generation aerospace structures. Resistance-welded joints combine the benefits of bonding with the capacity for high-volume manufacturing rates and eliminate the need for complex surface preparation. The influence of key welding parameters on the joint performance is investigated by assessing the Mode I fracture toughness. Double Cantilever Beam specimens with different welding parameter combinations are manufactured, tested and compared with each other. Thermoset laminates are made weldable by co-curing a chemically compatible thermoplastic film with an uncured thermoset laminate. A Bayesian approach is used to study the correlation between processing parameters and to select parameters yielding high performance by training a Gaussian process emulator. Observed Mode I fracture toughness values are comparable to high-performance thermoplastic composites. This is equivalent to an improvement of approximately 290 % in Mode I fracture toughness when compared to a co-cured thermoset joint.
通过电阻焊接连接热固性复合材料为下一代航空航天结构提供了一种新型的高效装配方法。电阻焊接接头兼具粘接的优点和大批量生产的能力,而且无需进行复杂的表面处理。通过评估模式 I 断裂韧性,研究了关键焊接参数对接头性能的影响。对不同焊接参数组合的双悬臂梁试样进行了制造、测试和比较。通过将化学相容的热塑性薄膜与未固化的热固性层压板共同固化,使热固性层压板具有可焊性。贝叶斯方法用于研究加工参数之间的相关性,并通过训练高斯过程仿真器来选择产生高性能的参数。观察到的模式 I 断裂韧性值与高性能热塑性复合材料相当。这相当于与共固化热固性连接相比,模式 I 断裂韧性提高了约 290%。
Facilely fabricated Janus polymer film for actuator and self-powered sensor
Peng Fei, Shan Tingting, Chen Rongrui, Shi Jiulong, Liu Di, Zheng Guoqiang, Gao Chaojun, Dai Kun, Liu Chuntai, Shen Changyu
doi:10.1016/j.compositesa.2023.107908
用于致动器和自供电传感器的简易制备的 Janus 聚合物薄膜
Janus polymer films (JPFs) have drawn increasing attention recently, owing to their distinct surface performance and potential applications. However, it still remains challenged to fabricate robust JPFs for actuator and self-powered sensor by a facile method. Herein, via facile vacuum-assisted hot-compressing method (VAHM) and spray coating, JPFs were successfully prepared, whose electrode and piezoelectric/actuation layer are respectively single-walled carbon nanotubes (SWCNTs) layer and micropatterned polyvinylidene fluoride (PVDF) layer. Moreover, JPFs show decent actuation performance (bending to 990° in 0.93 s) because of high molecular orientation level and asymmetric swelling of micropatterned surfaces. Meanwhile, such JPFs show rapid self-powered sensing property (response and recovery time of 1.3 s and 1.2 s, respectively) when deformed in acetone vapor, because of the inherent piezoelectricity of PVDF. Accordingly, a real-time acetone monitoring (RTAM) system was successfully constructed in virtue of Internet of Things (IoT) technology. This work proposes a facile way to develop low-cost and durable JPFs, and further combines actuation performance with self-powered sensing property, paving a creative way to construct functional architecture based on the concept of polymer “structuring” processing.
杰纳斯聚合物薄膜(JPFs)因其独特的表面性能和潜在的应用前景而受到越来越多的关注。然而,如何用简便的方法制备用于致动器和自供电传感器的坚固耐用的 JPF 仍是一个挑战。本文通过简便的真空辅助热压法(VAHM)和喷涂法成功制备了 JPF,其电极和压电/致动层分别为单壁碳纳米管(SWCNTs)层和微图案聚偏二氟乙烯(PVDF)层。此外,由于高分子取向水平和微图案表面的不对称膨胀,JPF 显示出良好的致动性能(在 0.93 秒内弯曲至 990°)。同时,由于 PVDF 固有的压电性,这种 JPF 在丙酮蒸汽中变形时显示出快速的自供电传感特性(响应和恢复时间分别为 1.3 秒和 1.2 秒)。因此,利用物联网技术成功构建了丙酮实时监测(RTAM)系统。这项工作提出了一种开发低成本、耐用型 JPF 的简便方法,并进一步将致动性能与自供电传感特性相结合,为基于聚合物 "结构化 "加工概念的功能性架构的构建铺平了一条创新之路。
A new strategy for PEEK-based biocomposites to achieve porous surface for bioactivity and adjustable mechanical properties for orthopedic stress matching
Li Shuai, Li Menglei, Hu Jiqiang, Li Gao, Wang Bing, Zhou Zhengong
doi:10.1016/j.compositesa.2023.107909
基于聚醚醚酮(PEEK)的生物复合材料实现多孔表面的生物活性和可调机械性能的新策略,用于骨科应力匹配
Polyetheretherketone (PEEK) has been widely used in orthopedic implants because of its prime biocompatibility. However, the bioinertness and single mechanical behavior limit its advanced clinical applications. In this study, carbon fiber reinforced surface porous PEEK/hydroxyapatite (HA) (CFR-SP-PEEK/HA) composites were designed and fabricated using the lamina layup-heat press-alkali solution corrosion method and characterized by mechanical tests. Theoretical models and numerical simulations were performed to further analyze the mechanical responses and inner failure mechanisms of CFR-SP-PEEK/HA. Close agreement between the numerical, theoretical and experimental results was observed. Human bones have different elastic modulus under tensile, compressive and bending loads, and the orthotropy of CFR-SP-PEEK/HA improved its ability to match the modulus of the human bone under different loads by adjusting the stacking sequence. The porous PEEK/HA composites on the sample surfaces exhibited potential bioactivity. Overall, CFR-SP-PEEK/HA is a highly competitive candidate for bone restoration and has great potential for medical applications.
聚醚醚酮(PEEK)具有良好的生物相容性,已被广泛应用于骨科植入物。然而,其生物惰性和单一的机械性能限制了它在临床上的广泛应用。本研究采用层叠-热压-碱溶液腐蚀法设计和制造了碳纤维增强表面多孔 PEEK/ 羟基磷灰石(HA)(CFR-SP-PEEK/HA)复合材料,并通过力学测试对其进行了表征。为了进一步分析 CFR-SP-PEEK/HA 的机械响应和内部失效机理,还建立了理论模型并进行了数值模拟。结果表明,数值、理论和实验结果非常接近。人体骨骼在拉伸、压缩和弯曲载荷下具有不同的弹性模量,CFR-SP-PEEK/HA 的正交性提高了其在不同载荷下通过调整堆叠顺序匹配人体骨骼模量的能力。样品表面的多孔 PEEK/HA 复合材料具有潜在的生物活性。总之,CFR-SP-PEEK/HA 是一种极具竞争力的骨修复候选材料,在医疗应用方面具有巨大潜力。
Asymmetric wettability fibrous membranes: Preparation and biologic applications
Zhang Mingyu, Chu Lei, Chen Jiahua, Qi Fuxun, Li Xiaoyan, Chen Xinliang, Yu Deng-Guang
doi:10.1016/j.compositesb.2023.111095
非对称润湿性纤维膜:制备和生物应用
Fibrous membranes with asymmetric wettability have attracted great interest. Benefiting from the inspiration of biological paradigms and the development of fabrication techniques, many asymmetric wettability membranes with well-designed surface topologies and chemical compositions have been reported in the literature. In this review, different structures of asymmetric wetted fibrous membranes are discussed, including Janus, sandwich, gradient, and hierarchy structure. Various top-down and bottom-up methods for the construction of asymmetric wetted fibrous membranes are summarized, including template, etching, surface modification, phase separation, self-assembly, electrospinning/electrospraying, and various composite methods. Furthermore, biological applications of asymmetric wetted fibrous membranes, such as smart fabrics, sensors, drug release, wound dressings, and tissue patches, are reviewed. Future challenges for asymmetric wettability fibrous membranes are suggested.
具有非对称润湿性的纤维膜引起了人们的极大兴趣。得益于生物范例的启发和制造技术的发展,许多具有精心设计的表面拓扑结构和化学成分的非对称润湿膜已见诸文献报道。本综述讨论了非对称润湿纤维膜的不同结构,包括 Janus 结构、三明治结构、梯度结构和层次结构。综述了构建非对称润湿纤维膜的各种自上而下和自下而上的方法,包括模板法、蚀刻法、表面改性法、相分离法、自组装法、电纺丝/电喷法以及各种复合方法。此外,还综述了非对称润湿纤维膜的生物应用,如智能织物、传感器、药物释放、伤口敷料和组织补片。还提出了非对称润湿纤维膜未来面临的挑战。
On the post-impact fatigue behavior and theoretical life prediction of CF/PEEK-titanium hybrid laminates using an energy dissipation approach
Ji Chunming, Hu Jiqiang, Alderliesten René, Yang Jinchuan, Zhou Zhengong, Sun Yuguo, Wang Bing
doi:10.1016/j.compscitech.2023.110354
使用能量耗散方法研究 CF/PEEK 钛混合层压板的冲击后疲劳行为和理论寿命预测
This paper aims to illustrate the effect of the impact damage on fatigue behavior of CF/PEEK-titanium hybrid laminates. To achieve this end, a fatigue life model was proposed to predict the S–N curves of the laminates at various initial impact energy levels and stress ratios based on the energy dissipation approach. The energy dissipation behavior of the laminates during fatigue loading under different experimental conditions was analyzed through a large amount of post-impact fatigue tests, and the correlation between the initial impact damage and the total fatigue dissipation energy was determined. The full-field axial strain distribution of the titanium layer on the impacted side of the laminate was characterized in terms of initial impact energy level and maximum stress using digital image correlation, and then the post-impact fatigue failure mechanism of CF/PEEK-Ti hybrid laminates was summarized. Finally, the validity of the proposed model was verified by fatigue tests under other conditions of stress ratio and impact energy level. It is worth mentioning that the proposed model is also applicable to other types of FMLs, and can accurately predict the residual fatigue life of laminates after impact with only one set of S–N curve data.
本文旨在说明冲击损伤对 CF/PEEK 钛混合层压板疲劳行为的影响。为此,本文基于能量耗散方法,提出了一种疲劳寿命模型,用于预测层压板在不同初始冲击能量水平和应力比条件下的 S-N 曲线。通过大量的冲击后疲劳试验,分析了层压板在不同试验条件下疲劳加载时的耗能行为,并确定了初始冲击损伤与总疲劳耗能之间的相关性。利用数字图像相关技术从初始冲击能量水平和最大应力两个方面表征了层压板冲击侧钛层的全场轴向应变分布,然后总结了 CF/PEEK-Ti 混合层压板的冲击后疲劳失效机理。最后,通过在其他应力比和冲击能级条件下的疲劳试验验证了所提模型的有效性。值得一提的是,所提出的模型还适用于其他类型的 FML,只需一组 S-N 曲线数据就能准确预测层压板在冲击后的残余疲劳寿命。