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【新文速递】2024年6月1日复合材料SCI期刊最新文章

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今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Science and Technology 7 篇

Composite Structures

Easy manufacturing constraint based topology optimization of dual-scale and dual-constituent lattice metastructure with thermal dimensional stability

Zihao Yang, Yongcun Zhang, Shutian Liu

doi:10.1016/j.compstruct.2024.118247

基于易于制造约束的具有热尺寸稳定性的双尺度双组份晶格元结构拓扑优化

Thermal dimensional stability (TDS) is a crucial issue in the development of high-end industry equipment and precision instruments that work in fluctuating thermal environments. To endow meta-structures with high load-carrying capacity and TDS functionality simultaneously, this paper proposes a topology optimization framework to optimize the topologies of lattice meta-structures at macroscopic structural and microscopic material scales concurrently. An important feature of the current optimization model is the introduction of a material concentration distribution (MCD) constraint to reduce the number of dual-constituent interfaces (DIs), which enables the easy manufacturing of the optimized structures because an additional fabrication process is required for the connection of heterogeneous lattice members. Designs for two dual-scale TDS structures, potentially employed for satellite payload platforms and the supporting structure of space telescopes, are completed. Compared with mono-scale TDS structures, the dual-scale schemes exhibit superior structural performances due to the opening of the dual-scale design space. Numerical experiments are performed to validate the ultra-low structural thermal deformations of the optimized TDS structures with values of 0.0743 μm/℃ and 0.153 μm/℃. Furthermore, the imposition of the MCD constraint significantly reduces the number of DIs from 38 to 10 within a lattice cell, enabling the easy assembly of the demonstrative 3D printing dual-constituent samples.

热尺寸稳定性(TDS)是开发在波动热环境下工作的高端工业设备和精密仪器的关键问题。为了使晶格元结构同时具有高承载能力和TDS功能,本文提出了一种拓扑优化框架,在宏观结构尺度和微观材料尺度上同时优化晶格元结构的拓扑结构。当前优化模型的一个重要特征是引入了材料浓度分布(MCD)约束,以减少双组分界面(DIs)的数量,这使得优化结构的制造变得容易,因为异质晶格成员的连接需要额外的制造工艺。完成了两种双尺度TDS结构的设计,可能用于卫星有效载荷平台和空间望远镜的支撑结构。由于双尺度设计空间的开放,与单尺度TDS结构相比,双尺度方案表现出更优越的结构性能。通过数值实验验证了优化后的TDS结构的超低结构热变形值分别为0.0743 μm/℃和0.153 μm/℃。此外,MCD约束的施加显着将晶格单元内的DIs数量从38个减少到10个,从而使演示性3D打印双组分样品的组装变得容易。


Composites Part A: Applied Science and Manufacturing

Limitations of composite strength theory for predicting the ultimate strengths of layered 3D printing polymers

Gonghe Zhang, Xiaodong Zheng, Qinglin Wang, Yinxu Ni, Fenghua Liu, Kai Zhao, Luoyu Roy Xu

doi:10.1016/j.compositesa.2024.108288

 

复合材料强度理论在预测层状3D打印聚合物极限强度方面的局限性

Composite laminates and 3D printing materials both have layered structures. Although the Tsai–Hill composite strength criterion is useful for predicting the strengths of some 3D printing polymers made with fused filament fabrication (FFF), our experimental and theoretical studies showed that this criterion has some limitations in predicting the strengths of other 3D printing polymers. In this study, a new quadratic strength criterion was employed to predict a conservative lower bound for the strengths of polymers made with FFF and selective laser sintering (SLS). The printing surface angles of the printing specimens ranged from 0° to 90°. Interestingly, the scope of this study unexpectedly widened from strength research to fracture mechanics research because dynamic crack branching was observed in some SLS specimens (printing surface angles ranged from 0° to 75°) under static tension—a novel phenomenon among 3D printing materials. Crack branching not only followed previous crack branching rules, such as rules on the crack speed and energy release but also presented new challenges for dynamic fracture mechanics theory.

复合层压板和3D打印材料都具有层状结构。虽然Tsai-Hill复合材料强度准则可用于预测某些用熔丝制造(FFF)制成的3D打印聚合物的强度,但我们的实验和理论研究表明,该准则在预测其他3D打印聚合物的强度方面存在一定的局限性。在这项研究中,采用一个新的二次强度准则来预测FFF和选择性激光烧结(SLS)聚合物强度的保守下界。印刷试样的印刷表面角度范围为0°~ 90°。有趣的是,这项研究的范围出乎意料地从强度研究扩大到断裂力学研究,因为在一些SLS样品(打印表面角度从0°到75°)中观察到静态张力下的动态裂纹分支,这是3D打印材料中的一种新现象。裂纹分支不仅遵循原有的裂纹分支规律,如裂纹速度和能量释放规律,而且对动态断裂力学理论提出了新的挑战。


Effect of long-time annealing at high temperature on the microstructure and mechanical properties of different types of SiC fibers

Shuang Wu, Yanzi Gou, Yu Xiang, Weifeng Kang, Yongshou Wang, Quzhi Song, Nana Xu, Yingde Wang

doi:10.1016/j.compositesa.2024.108291

高温长时间退火对不同类型SiC纤维显微组织和力学性能的影响

SiC fibers play a crucial role in ceramic-matrix composites due to their excellent high-temperature resistance. To analyze the high temperature stability of different types of SiC fibers, this work investigated three typical SiC fibers (KD-II, KD-S, KD-SA) after being annealed at 1600 °C and 1800 °C for 1 h ∼ 200 h, respectively. For annealing at 1600 °C, the decomposition of the SiCxOy phase and grain growth were the main reasons for strength degradation in KD-II and KD-S fibers, while the KD-SA fiber maintained good thermal stability due to its large grain size. For long-time annealing at 1800 °C, obvious Si sublimation in the three fibers, leading to appearance of skin-core structure, resulted in obvious strength decline. This phenomenon was more pronounced over 1800 °C. These results in this work could be helpful guidance for the preparation of higher performance SiC fibers and SiCf/SiC composites.

SiC纤维以其优异的耐高温性能在陶瓷基复合材料中起着至关重要的作用。为了分析不同类型SiC纤维的高温稳定性,本工作研究了三种典型的SiC纤维(KD-II, KD-S, KD-SA)在1600 °C和1800 °C分别退火1 h ~ 200 h后的高温稳定性。1600 ℃退火时,KD-II和KD-S纤维强度下降的主要原因是SiCxOy相的分解和晶粒长大,而KD-SA纤维由于晶粒尺寸大,保持了良好的热稳定性。在1800 ℃下长时间退火,三种纤维中Si明显升华,出现皮芯结构,强度下降明显。这种现象在1800° °C以上更为明显。研究结果对制备高性能SiC纤维和SiCf/SiC复合材料具有指导意义。


Composites Science and Technology

Temperature- and rate-dependent tensile behaviour of unidirectional carbon/polyamide-6 composite under off-axis loading with oblique tabs

Daniele Finazzi, Marco Bertani, Wim Van Paepegem

doi:10.1016/j.compscitech.2024.110685

 

斜片离轴载荷下单向碳/聚酰胺-6复合材料的温度和速率相关拉伸行为

Unidirectional carbon/polyamide-6 (CPA6) is a thermoplastic composite with attractive properties for many industrial applications. However, shortage of experimental data may hinder the development of reliable material models. This paper is the first to provide a complete dataset for the tensile behaviour of unidirectional CPA6, including the longitudinal, transverse, in-plane shear, and off-axis response, at different temperatures and (quasi-static) strain rates. The oblique end tab design, already proven in the literature for off-axis testing of composites at room temperature, was successfully extended to the elevated temperature of 120 °C. The use of cardboard tabs and fast-curing adhesive greatly simplified the tab manufacturing and application for all the combinations of fibre angles, temperatures and strain rates. Digital image correlation (DIC) was performed through the window of the temperature chamber to verify the homogeneous strain field produced by the oblique tabs. The in-plane shear behaviour was extracted from the off-axis tests, allowing to estimate the shear modulus and shear strength. Finally, the robustness of the experimental results generated in this study was demonstrated with well-established analytical models that could excellently predict the elastic modulus, Poisson’s ratio, and failure stress at different fibre angles.

单向碳/聚酰胺-6 (CPA6)是一种热塑性复合材料,具有许多工业应用的吸引力。然而,实验数据的缺乏可能会阻碍可靠材料模型的发展。本文首次提供了单向CPA6拉伸行为的完整数据集,包括在不同温度和(准静态)应变速率下的纵向、横向、面内剪切和离轴响应。在室温下的复合材料离轴测试中,斜端标签设计已经在文献中得到验证,并成功地扩展到120°C的高温。纸板标签和快速固化粘合剂的使用大大简化了标签的制造和应用,适用于纤维角度、温度和应变率的所有组合。通过温度室窗口进行数字图像相关(DIC),验证斜片产生的均匀应变场。从离轴试验中提取平面内剪切行为,从而可以估计剪切模量和剪切强度。最后,通过完善的分析模型证明了本研究实验结果的鲁棒性,该模型可以很好地预测不同纤维角度下的弹性模量、泊松比和破坏应力。


A three-dimensional viscoelastic-viscoplastic and viscodamage constitutive model for unidirectional fibre-reinforced polymer laminates

I.R. Cózar, P. Maimí, E.V. González, P.P. Camanho, F. Otero

doi:10.1016/j.compscitech.2024.110634

 

单向纤维增强聚合物层合板的三维粘弹粘塑性和粘损伤本构模型

A novel 3D viscoelastic-viscoplastic and viscodamage constitutive model is proposed to predict the viscous effects due to dynamic loading conditions of unidirectional carbon fibre-reinforced polymer laminates at the meso-scale level. The present model is developed under continuum damage mechanics and the thermodynamics of irreversible processes framework. The viscoelastic response is modelled using the generalised Maxwell model, while an overstress model is employed to address the viscoplastic strain. The onset of the viscodamage mechanisms is based on experimental expressions, and their propagation is defined as a function of the corresponding fracture toughness. The mechanical response of the present constitutive model under pure longitudinal shear loading conditions at different strain rates is presented. The higher the strain rate is, the stiffer the responses in the viscoelastic and viscoplastic regions. Additionally, the onset of viscodamage increases with higher strain rates. Off-axis compressive experimental data at two different strain rates are employed to demonstrate the capabilities of the present model with good predictions being obtained.

提出了一种新的三维粘弹-粘塑性和粘损伤本构模型,用于在细观尺度上预测单向碳纤维增强聚合物层合板在动态加载条件下的粘滞效应。该模型是在连续损伤力学和不可逆过程热力学框架下建立的。粘弹性响应采用广义Maxwell模型,粘塑性应变采用超应力模型。粘损伤机制的开始是基于实验表达式的,其扩展被定义为相应断裂韧性的函数。给出了本构模型在不同应变率下纯纵向剪切加载条件下的力学响应。应变率越高,粘弹区和粘塑性区的响应越硬。此外,粘胶损伤的发生随着应变速率的增加而增加。采用两种不同应变速率下的离轴压缩实验数据来证明该模型的能力,并获得了良好的预测结果。


Multimodal Electrohydrodynamic Jet Printing-Based Microstructure-Sensitized Flexible Pressure Sensor

Hongji Guo, Wuhao Zou, Tianming Zhao, Jiawen Liang, Ya Zhong, Peilin Zhou, Ying Zhao, Lianqing Liu, Haibo Yu

doi:10.1016/j.compscitech.2024.110686

 

基于多模态电流体动力喷射打印的微结构敏化柔性压力传感器

Surface modification with micro/nanostructures is a common approach for enhancing the performance of flexible pressure sensors. However, the current fabrication of the singular functionality of instruments and redundancy of processes increase the complexity of the sensor manufacturing process. In this study, we developed a multilayer microstructure-enhanced flexible capacitive pressure sensor based on the multimodal electrohydrodynamic jet (E-jet) printing technology. The experimental results demonstrate that the sensors incorporating the microstructure-sensitized electrode layer and the polyvinyl alcohol/graphene/polydimethylsiloxane dielectric layer exhibit the following characteristics: high sensitivity (0.3139 kPa-1/0-2 kPa), low limit of detection (∼100 mg), and stable performance even after 10,000 cycles. Moreover, microstructure-enhanced sensors have considerable potential for human behavior detection, such as detecting fluid flow, tracking muscle movements, and measuring pulse rates. Finally, microstructure-enhanced sensors fabricated using the E-jet printing method present a novel approach for designing sensitized structures in capacitive pressure sensors.

微纳结构表面改性是提高柔性压力传感器性能的常用方法。然而,目前制造的单一功能的仪器和冗余的过程增加了传感器制造过程的复杂性。在这项研究中,我们开发了一种基于多模态电流体动力射流(E-jet)打印技术的多层微结构增强柔性电容压力传感器。实验结果表明,包含微结构敏化电极层和聚乙烯醇/石墨烯/聚二甲基硅氧烷介电层的传感器具有以下特点:高灵敏度(0.3139 kPa-1/0-2 kPa),低检测限(~ 100 mg),即使在10,000次循环后性能稳定。此外,微结构增强传感器在人类行为检测方面具有相当大的潜力,例如检测流体流动、跟踪肌肉运动和测量脉搏率。最后,利用E-jet打印技术制备的微结构增强传感器为电容式压力传感器的敏化结构设计提供了一种新的方法。


Closed loop recycling of electrically damaged meta-aramid papers with high electrical insulation and mechanical strength

Fangcheng Lv, Lvqian Fu, Qibin Wang, Kaixuan Sun, Rui Yang, Sidi Fan, Xiang Yu

doi:10.1016/j.compscitech.2024.110688

 

具有高电绝缘性和机械强度的电损坏间位芳纶纸的闭环回收

High-performance aramid papers are ideal insulating materials in the electric industry, due to their superior mechanical strength and insulation capabilities. However, when subjected to prolonged high-voltage and high-power operations, these papers are prone to electrical damage, such as breakdown or corona aging. Unfortunately, most damaged aramid papers are viewed as mere waste, discarded through landfill or other unsustainable disposal methods. It is not only contrary to circular economy principles but also poses a significant environmental threat due to the potential for pollution. Herein, a closed-loop recycling strategy is proposed that efficiently and effectively reclaims electrically damaged meta-aramid papers. Using the DMAc/LiCl deprotonation system, waste aramid papers are completely decomposed into molecular chains, exposing carbon residues resulting from electrical breakdown. These carbon residues are removed through a step-by-step purification process. A reprotonation treatment is then applied to regenerate new meta-aramid papers by reforming the intermolecular hydrogen bonds. This approach not only fully restores the original honeycomb-like structure but also ensures the crystallization and hydrogen bond content, maintaining both electrical and mechanical properties at above 90% of their original values. Notably, our recycling method is also compatible with aramid-based composites, achieving exceptional recycling efficiency.

高性能芳纶纸具有优异的机械强度和绝缘性能,是电气工业中理想的绝缘材料。然而,当经受长时间的高压和大功率操作时,这些纸张容易发生电气损坏,例如击穿或电晕老化。不幸的是,大多数受损的芳纶纸被视为纯粹的废物,通过填埋或其他不可持续的处理方法被丢弃。它不仅违背了循环经济原则,而且由于潜在的污染,对环境构成了重大威胁。本文提出了一种闭环回收策略,可以高效、有效地回收电损伤的间位芳纶纸。使用DMAc/LiCl去质子化系统,废弃芳纶纸被完全分解成分子链,暴露出电击穿产生的碳残基。这些碳残留物通过一步一步的净化过程被去除。然后通过重组分子间氢键,应用再生处理再生新的间芳纶纸。这种方法不仅完全恢复了原始的蜂窝状结构,而且保证了结晶和氢键含量,使电学和力学性能保持在原始值的90%以上。值得注意的是,我们的回收方法也与芳纶基复合材料兼容,实现了卓越的回收效率。


Construction of a cross-bedded tea polyphenol delivery structure in ultrahigh molecular weight polyethylene against bacteria for joint replacement

Yue Ren, Jia-Cheng Lv, Shao-Peng Zhao, Haojie Fu, Zhao-Bo Sun, Lingli Li, Shishu Huang, Jia-Zhuang Xu, Zhong-Ming Li

doi:10.1016/j.compscitech.2024.110689

 

超高分子量聚乙烯抗细菌交叉层状茶多酚传递结构的构建

The high jeopardy of prosthesis joint infection demands urgent development of an in-situ drug delivery joint material, while achieving sustained antimicrobial activity remains a challenge. Herein, a sedimentary rock-like “cross-bedded” drug delivery structure was constructed in the ultrahigh molecular weight polyethylene (UHMWPE) joint material. Epigallocatechin gallate (EGCG), a representative tea polyphenol, was employed as a substitute of antibiotics with antimicrobial activity. Delivery pathways composed of EGCG were highly aligned and cross-bedded with the UHMWPE matrix under the strong flow field offered by solid-state extrusion. The EGCG pathlength was thus increased in a longitudinal section, attenuating burst release and prolonging the release time of EGCG. The release of EGCG in the “cross-bedded” structure was restricted to a low concentration at the initial stage yet subsequently extended 2∼3 times compared to that in the massive structure. The prolonged release ratio is nearly equivalent to the EGCG pathlength increment as calculated via a simplified mathematical model. The quantitative relationships between release behavior and antimicrobial performance proved that the cross-bedded structure was efficient in maintaining sustained antimicrobial activity. These findings offer a paradigm to achieve sustained drug therapy in UHMWPE joint material, which is constructive for treating prosthetic bacterial infections in clinical trials.

假体关节感染的高危险性迫切需要原位给药关节材料的开发,而实现持续的抗菌活性仍然是一个挑战。本文在超高分子量聚乙烯(UHMWPE)接头材料中构建了类似沉积岩的“交叉层状”给药结构。表没食子儿茶素没食子酸酯(EGCG)是一种具有代表性的茶多酚,可作为抗菌药物的替代品。在固态挤压提供的强流场下,EGCG组成的传递途径与UHMWPE基质高度排列并交叉层状。因此,EGCG的路径长度在纵剖面上增加,减缓了爆发释放,延长了EGCG的释放时间。在“交叉层状”结构中,EGCG的释放在初始阶段被限制在低浓度,但随后比在块状结构中延长了2 ~ 3倍。通过简化的数学模型计算,延长释放比几乎等于EGCG路径长度增量。释放行为与抗菌性能之间的定量关系证明了交层结构在维持持续抗菌活性方面是有效的。这些发现为实现UHMWPE关节材料的持续药物治疗提供了一个范例,这对临床试验中治疗假体细菌感染具有建设性意义。


Multifunctional polyimide/boron nitride nanosheet/Ti3C2Tx MXene composite film with three-dimensional conductive network for integrated thermal conductive, electromagnetic interference shielding, and Joule heating performances

Dongya Guo, Binzhe Tan, Xiaojie Jiang, Guangyu Gao, Yu Lin

doi:10.1016/j.compscitech.2024.110690

 

具有三维导电网络的多功能聚酰亚胺/氮化硼纳米片/Ti3C2Tx MXene复合薄膜,具有综合导热、电磁干扰屏蔽和焦耳加热性能

With the demand for further miniaturization and higher frequency operation of electronic devices, polymer films with high thermal conductivity and electromagnetic interference (EMI) shielding effectiveness (SE) are urgently required. Herein, polyimide (PI)/boron nitride nanosheets (BNNS) aerogels with oriented porous structure are fabricated by unidirectional-freezing and freeze-drying methods. Subsequently, hierarchical PI/BNNS/Ti3C2Tx composite films with consecutively electrically and thermally conductive networks are successfully prepared via a unidirectional PI/BNNS aerogels-assisted immersion and hot-pressing strategy. Owing to the three-dimensional conductive dual networks of BNNS and Ti3C2Tx, the composite film exhibits excellent thermal conductivity with the maximum in-plane value of 4.73 W/(m·K), increased by 456% compared to pure PI film. Moreover, the conductive network of Ti3C2Tx is conducive to the excellent EMI shielding performance, endowing the PI/BNNS/Ti3C2Tx composite film with an outstanding EMI SE value of 49.2 dB at 8.2 GHz with a low MXene content of 6 wt% and thickness of 300 μm. Furthermore, the composite film shows the superior Joule heating performance with fast thermal response and sufficient reliability. Therefore, the resulting composite film exhibits excellent thermal conductive, EMI shielding and Joule heating performance, which enables the potential application of multifunctional composites for thermal management and EMI shielding.

随着电子器件进一步小型化和高频率工作的要求,迫切需要具有高导热性和屏蔽电磁干扰(EMI)效能的聚合物薄膜。本文采用单向冷冻和冷冻干燥的方法制备了具有定向多孔结构的聚酰亚胺/氮化硼纳米片气凝胶。随后,通过单向PI/BNNS气凝胶辅助浸渍和热压策略,成功制备了具有连续导电和导热网络的分层PI/BNNS/Ti3C2Tx复合薄膜。由于BNNS和Ti3C2Tx的三维双导网络,复合膜具有优异的导热性能,最大面内值为4.73 W/(m·K),比纯PI膜提高了456%。此外,Ti3C2Tx的导电网络有利于优异的EMI屏蔽性能,使得PI/BNNS/Ti3C2Tx复合膜在8.2 GHz时具有49.2 dB的优异EMI SE值,MXene含量低至6 wt%,厚度为300 μm。复合膜具有良好的焦耳加热性能,热响应快,可靠性高。因此,所得到的复合膜具有优异的导热、电磁干扰屏蔽和焦耳加热性能,这使得多功能复合材料在热管理和电磁干扰屏蔽方面的潜在应用成为可能。


Thickness effect on ballistic impact behavior of hybrid carbon/Kevlar composites

Sai Zhao, Jia Huang, Junchao Cao, Yong Chen, Xiaobiao Zuo, Kai Yi, Chao Zhang

doi:10.1016/j.compscitech.2024.110692

 

厚度对混杂碳/凯夫拉复合材料弹道冲击性能的影响

Carbon fiber composites have poor impact resistance that constrains their wider application in advanced engineering structures, and hybridizing carbon fibers with Kevlar fibers is an effective method to enhance their impact resistance. The ballistic impact resistance can be optimized through regulating the hybridization layout and hybrid ratio, which requires systematically exploration on the inherent failure mechanism. In this work, the ballistic impact behavior of hybrid carbon/Kevlar fiber reinforced epoxy laminates against flat-head projectile are systematically investigated. Hybrid specimens with different thicknesses and hybridization ratios are designed, tested and compared. The results reveal the strong correlation between thickness and ballistic impact performance. When laminates are relatively thin, Kevlar fiber layers at the back surface impart superior impact resistance. In contrast, the opposite result is observed when the thickness is beyond a threshold value. With an increase in the Kevlar fiber hybridization ratio, this threshold value will occur in thinner laminates. Further analysis indicates that this phenomenon is related to a shear plugging effect that dominates the different modes of impact failure.

碳纤维复合材料抗冲击性能较差,制约了其在先进工程结构中的广泛应用,碳纤维与凯夫拉纤维杂交是增强其抗冲击性能的有效方法。通过调节混合布局和混合比例来优化其抗弹道冲击性能,这需要对其内在失效机理进行系统的探索。本文系统地研究了复合碳纤维/芳纶增强环氧复合材料对平头弹丸的弹道冲击性能。设计、试验和比较了不同厚度和杂交比的杂交试样。结果表明,厚度与弹道冲击性能之间存在很强的相关性。当层压板相对较薄时,背面的凯夫拉纤维层具有优异的抗冲击性。相反,当厚度超过阈值时,观察到相反的结果。随着凯夫拉纤维杂化比的增加,该阈值将出现在较薄的层压板中。进一步分析表明,这种现象与剪切堵塞效应有关,剪切堵塞效应在不同的冲击破坏模式中占主导地位。


来源:复合材料力学仿真Composites FEM
ACTMechanicalMaxwellSystemMarc断裂复合材料拓扑优化电子裂纹理论材料试验电气
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【新文速递】2024年6月7日复合材料SCI期刊最新文章

今日更新:Composite Structures 1 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 1 篇Composite StructuresEnergy absorption characteristics of modular assembly structures under quasi-static compression loadQiqi Li, Weijun Wang, Hailun Tan, Xiangyun Long, Fang Wang, Lin Hudoi:10.1016/j.compstruct.2024.118260准静态压缩载荷下模块化装配结构的能量吸收特性Inspired by the assembly of building blocks, an innovative modular assembly structure (MAS) is proposed. With its modular design and versatility, MAS can be tailored to diverse working environments and task requirements. A prototype MAS is generated through three-dimensional (3D) printing, and subsequent compression tests consistently display energy absorption performance akin to a finite element model, affirming the validity of the simulations. Multiple MASs are obtained through the assembly of oblique cross cells, and the effect of compression direction on the energy absorption capacity of MASs is discussed. It is found that transverse compression outperforms longitudinal compression in energy absorption, and MAS with four cells and transverse loading demonstrates the highest specific energy absorption (SEA) value. Furthermore, quadrilateral, pentagonal, and hexagonal cells are proposed to obtain more MASs, and the compression performance of these MASs is evaluated by varying the frame structure thickness d and supporting structure thickness j of cells. Results highlight the superior energy absorption efficiency of the pentagonal element structure. Notably, parameter d has a more pronounced impact on energy absorption compared with parameter j. When j is 2.0 mm and d increases from 1.0 mm to 2.0 mm, the SEA values of quadrilateral, pentagonal, and hexagonal MASs increase by 113.70, 139.45, and 86.25 J/kg. In summary, MASs exhibit impressive energy absorption capabilities, promising versatile applications in energy absorption and anti-collision mechanisms across various scenarios.受积木装配的启发,提出了一种创新的模块化装配结构(MAS)。凭借其模块化设计和多功能性,MAS可以根据不同的工作环境和任务要求进行定制。通过三维(3D)打印生成MAS原型,随后的压缩测试一致显示类似于有限元模型的能量吸收性能,证实了模拟的有效性。通过斜交叉单元的装配获得了多个质量,并讨论了压缩方向对质量吸能能力的影响。结果表明,横向压缩比纵向压缩更能吸收能量,且四胞体横向加载的MAS比能吸收(SEA)值最高。此外,还提出了四边形、五边形和六边形单元来获得更多的质量,并通过改变单元的框架结构厚度d和支撑结构厚度j来评估这些质量的压缩性能。结果表明,五边形单元结构具有较好的吸能效率。当j = 2.0 mm, d从1.0 mm增加到2.0 mm时,四边形、五边形和六边形质量的SEA值分别增加113.70、139.45和86.25 j /kg。总之,MASs表现出令人印象深刻的能量吸收能力,在各种情况下的能量吸收和防碰撞机制中有广泛的应用前景。Composites Part B: EngineeringLarge deformation behavior and energy absorption of rotating square auxeticsFereshteh Hassani, Zia Javanbakht, Sardar Malekdoi:10.1016/j.compositesb.2024.111596旋转方形消声器的大变形行为和能量吸收This study focuses on large deformation in-plane response of rotating square (RS) auxetics under quasi-static tension with an emphasis on their energy absorption (EA). First, metallic RS samples were fabricated and tested under uniaxial tension and the results were used to establish validated numerical models using ANSYS. Gurson–Tvergaard–Needleman (GTN) model was employed to evaluate the ductile damage and its capability to predict failure of the RS structure was investigated. Numerical analyses were then conducted to compare the large tensile responses of a regular RS (R-RS) and a bio-inspired RS (Bio-RS-0) introduced by Sorrentino et al. (2022). Subsequently, a parametric study evaluated the effect of the size of a circular perforation in the square region of the Bio-RS-0 on the stress distribution, force–deformation response, failure mechanism, and specific energy absorption (SEA) of the structures. Bio-RS-0 enhanced the SEA of R-RS by more than five times due to the increased engagement of the geometry in plastic deformation. Large perforations significantly influenced the response in larger strains and their failure mode. Two failure mechanisms were identified which could be adjusted by perforation size. An optimum perforation size and the corresponding failure mode were identified for maximum SEA. Potential applications for energy absorbing auxetics in tension were discussed at the end.本文主要研究了准静态张力作用下旋转方形结构的面内大变形响应,重点研究了其能量吸收特性。首先,制备金属RS试样并进行单轴拉伸试验,利用ANSYS软件建立验证的数值模型。采用Gurson-Tvergaard-Needleman (GTN)模型对RS结构的韧性损伤进行了评估,并对其预测破坏的能力进行了研究。然后进行数值分析,比较Sorrentino等人(2022)推出的普通RS (R-RS)和仿生RS (Bio-RS-0)的大拉伸响应。随后,进行了参数化研究,评估了Bio-RS-0方形区域中圆形穿孔的大小对结构应力分布、力-变形响应、破坏机制和比能吸收(SEA)的影响。Bio-RS-0将R-RS的SEA提高了5倍以上,因为它增加了几何形状在塑性变形中的参与度。大孔洞对大应变下的响应及其破坏模式有显著影响。确定了两种破坏机制,它们可以通过射孔尺寸来调节。确定了最佳射孔尺寸和相应的破坏模式,以获得最大的SEA。最后讨论了张力吸能助剂的潜在应用。Design and manufacturing of a thermoplastic composite fan blade: Process-induced deformation simulation with fiber-draping analysis and its experimental validationThuan Ho-Nguyen-Tan, Min-Hyeok Jeon, Kyung Seok Jung, Jaesang Yu, Minkook Kim, Soon Ho Yoondoi:10.1016/j.compositesb.2024.111599 热塑性复合材料风扇叶片的设计与制造:工艺变形模拟与纤维垂起分析及其实验验证This paper presents an efficient methodology for designing and manufacturing a thermoplastic composite (TPC) fan blade. The structural thickness distribution is employed to define the lamination ply layup on middle shell mesh of the fan blade. Ply shape codes with high manufacturability are constructed using the marching square algorithm. A numerical analysis of fiber-draping is proposed to predict the distortion of fiber orientations due to shell curvatures and twisted angles. These fiber orientations are employed to simulate the process-induced deformation resulting from thermal anisotropy in the TPC fan blade. The simulated process-induced deformations accounting for the fiber-draping analysis closely align with experimental results.本文提出了一种设计和制造热塑性复合材料(TPC)风扇叶片的有效方法。采用结构厚度分布来确定风机叶片中壳网的层压厚度。采用行进平方算法构造了具有高可制造性的铺层形状码。提出了一种纤维悬垂的数值分析方法,以预测由于壳体曲率和扭转角引起的纤维取向畸变。这些纤维取向被用来模拟由TPC风扇叶片的热各向异性引起的过程诱导变形。模拟过程引起的变形与实验结果吻合较好。Biodegradable PLLA/PLGA Microspheres/Collagen Composites for Continuous Soft Tissue AugmentationXuan Li, Xiangyi Liao, Zhenzhen Jia, Shuaiyin Liu, Ping Li, Li Li, Wei Zhang, Xufeng Niu, Yubo Fandoi:10.1016/j.compositesb.2024.111603生物可降解PLLA/PLGA微球/胶原复合材料用于连续软组织增强Skin aging is caused by a combination of endogenous and exogenous factors. The dryness, roughness, and pigmentation can be improved by chemical peeling and laser irradiation, while skin sagging mainly relies on dermal fillers. Although collagen fillers and microspheres fillers can fill the skin, neither of them can provide a sustained filling effect. Herein, a kind of dermal filler composed of collagen, poly(L-lactic acid) (PLLA) and poly(lactic-co-glycolic acid) (PLGA) (PLLA/PLGA microspheres/collagen) is developed to make up for the above shortcomings. PLLA/PLGA microspheres/collagen has good injectability and biocompatibility. In vitro studies indicate that PLGA microspheres of Col-50%PLLA/PLGA and Col-25%PLLA/PLGA show massive degradation on day 1 of complete collagen degradation, meeting the study objectives of continuous improvement of skin sagging. Furthermore, injecting composites into SD rats, 50%PLLA/PLGA and Col-25%PLLA/PLGA are proven with macrophage infiltration, TGF-β expression, and endogenous collagen regeneration. The developed PLLA/PLGA microspheres/collagen composites with good biocompatibility and sustained filling property hold great promise for improved treatment of skin sagging as well as other soft tissue augmentation.皮肤老化是由内源性和外源性因素共同引起的。皮肤干燥、粗糙、色素沉着可以通过化学脱皮和激光照射来改善,而皮肤松弛主要依赖于真皮填充剂。虽然胶原蛋白填充剂和微球填充剂可以填充皮肤,但它们都不能提供持续的填充效果。为了弥补上述不足,本课题研制了一种由胶原蛋白、聚l -乳酸(PLLA)和聚乳酸-羟基乙酸(PLGA) (PLLA/PLGA微球/胶原)组成的真皮填充剂。PLLA/PLGA微球/胶原蛋白具有良好的注射性和生物相容性。体外研究表明,Col-50%PLLA/PLGA和Col-25%PLLA/PLGA微球在胶原蛋白完全降解第1天出现大量降解,满足持续改善皮肤松弛的研究目标。此外,将复合材料注射到SD大鼠体内,50%PLLA/PLGA和Col-25%PLLA/PLGA均证实了巨噬细胞浸润、TGF-β表达和内源性胶原再生。所开发的PLLA/PLGA微球/胶原复合材料具有良好的生物相容性和持续填充性能,在改善皮肤松弛和其他软组织增大的治疗方面具有很大的前景。On asymmetric failure in additively manufactured continuous carbon fiber reinforced compositesJunjie Luo, Ke Zou, Quantian Luo, Qing Li, Guangyong Sundoi:10.1016/j.compositesb.2024.111605 增材制造连续碳纤维增强复合材料的不对称失效研究Due to a filament-by-filament and layer-by-layer structure produced by an additive manufacturing (or namely 3D printing) technique, mechanical properties of 3D printed materials diverge considerably from those of carbon fiber reinforced polymer (CFRP) composites made by traditional processes. This study aims to experimentally characterize their mechanical properties through the off-axis tensile, compressive and V-notch shear tests. Advanced imaging techniques, such as digital image correlation (DIC), scanning electron microscopy (SEM) and computed tomography (CT), are used to investigate anisotropic nature of materials and failure mechanisms of the 3D printed CFRP composites. The applicability of conventional failure criteria to the 3D printed CFRP composites, including Tsai-Wu, Tsai-Hill, Hoffman, Maximum Stress, Hashin, Puck and LaRC05, is assessed systematically. The experimental results divulge that the filament-by-filament and layer-by-layer features intrinsic to 3D printed CFRP composites lead to an uneven yet organized distribution of voids. This characteristic contributes on the development of claw mark strain patterns, parallel track inter-fiber failure patterns, and distinct compression failure modes such as delamination and interlayer crack under loading perpendicular to the fiber direction. The voids in the 3D printed CFRP materials are partially responsible for the significant asymmetry when off-axis angle increases. Notably, the conventional failure criteria exhibit limited capability for predicting the off-axis tensile strength accurately. This phenomenon can be attributed to the redistribution of inherent fiber waviness as the fiber encounters tensile loads. Based on the experimental results, the inter-fiber failure within LaRC05 is modified to obtain an enhanced failure criterion for predicting the off-axis tensile strength. This study is expected to provide fundamental understanding of structural characteristics and mechanical properties for 3D printed CFRP composites.由于增材制造(即3D打印)技术生产的细丝和层层结构,3D打印材料的机械性能与传统工艺制造的碳纤维增强聚合物(CFRP)复合材料有很大差异。本研究旨在通过离轴拉伸、压缩和v形缺口剪切试验对其力学性能进行实验表征。采用数字图像相关(DIC)、扫描电子显微镜(SEM)和计算机断层扫描(CT)等先进成像技术,研究了3D打印CFRP复合材料的各向异性特性和破坏机制。系统评估了传统失效准则对3D打印CFRP复合材料的适用性,包括Tsai-Wu、Tsai-Hill、Hoffman、Maximum Stress、Hashin、Puck和LaRC05。实验结果表明,3D打印CFRP复合材料的细丝与逐层特性导致了不均匀但有组织的空隙分布。这一特性导致在垂直于纤维方向的载荷作用下产生爪痕应变模式、平行径迹纤维间破坏模式以及明显的分层和层间裂纹等压缩破坏模式。当离轴角增大时,3D打印CFRP材料中存在的空隙是造成不对称现象的部分原因。值得注意的是,传统的破坏准则在准确预测离轴抗拉强度方面的能力有限。这种现象可归因于纤维遇到拉伸载荷时固有纤维波纹度的重新分配。基于实验结果,对LaRC05纤维间破坏进行了修正,得到了预测离轴拉伸强度的增强破坏准则。这项研究有望为3D打印CFRP复合材料的结构特性和力学性能提供基本的理解。Composites Science and Technology“Dual-armor” strategy to prepare multifunctional carbonyl iron particle with corrosion resistance, self-healing and high microwave absorbing performancesKaka Li, Junbo Ge, Dongjie Zhang, Ruoxi Zhao, Chao Wu, Zhongjun Cheng, Zhimin Xie, Yuyan Liudoi:10.1016/j.compscitech.2024.110699 采用“双护甲”策略制备具有耐腐蚀、自愈和高吸收微波性能的多功能羰基铁颗粒As a common and high microwave absorbing material, the application fields of carbonyl iron particle (CIP) are limited because of its poor corrosion resistance when working in harsh environments such as ocean, rainforest, or other high-humidity, high-salt places. Therefore, it is necessary to design a multifunctional CIP with good corrosion resistance and self-healing properties for ensuring its stable microwave absorbing performance. Herein, a “dual-armor” strategy is proposed to prepare multifunctional CIP (Composite particle), which is assembled with CIP coated by polyaniline (PANI/CIP) and Fe-DSe-M. Fe-DSe-M is Fe3+ responsive microcapsule whose shell contains -Se-Se- bonds and is magnetically adsorbed on the surface of PANI/CIP. PANI/CIP and Fe-DSe-M jointly undertake the function of microwave absorbing, anti-corrosion and self-healing. It is worth to note that the microwave absorbing performance of CIP after multi-functionalization has been greatly improved, and the minimum reflection loss value after accelerated corrosion is only reduced by 5.46 dB, which is much lower than PANI/CIP. These excellent properties of functional Composite particle benefit from PANI protective layer, Fe3+ responsive self-healing Fe-DSe-M and their synergistic effect. Our work provides a new approach to fabricate multifunctional microwave absorbing particle, which has a potential application in the corrosive environment.羰基铁颗粒(CIP)作为一种常见的高吸波材料,在海洋、雨林或其他高湿、高盐场所等恶劣环境下工作时,由于其耐腐蚀性较差,其应用领域受到限制。因此,有必要设计一种具有良好耐腐蚀和自愈性能的多功能CIP,以确保其稳定的微波吸收性能。本文提出了一种“双护甲”策略来制备多功能CIP(复合粒子),该复合粒子由聚苯胺(PANI/CIP)和Fe-DSe-M包覆的CIP组装而成。Fe-DSe-M是一种Fe3+响应微胶囊,其外壳含有- se - se -键,并被磁吸附在PANI/CIP表面。PANI/CIP与Fe-DSe-M共同承担了微波吸收、防腐和自愈的功能。值得注意的是,CIP多功能化后的微波吸收性能有了很大的提高,加速腐蚀后的最小反射损失值仅降低了5.46 dB,远低于PANI/CIP。这些优异的性能得益于聚苯胺保护层、Fe3+响应自修复的fe - se - m及其协同作用。本研究为制备多功能微波吸收粒子提供了一条新途径,在腐蚀环境中具有潜在的应用前景。来源:复合材料力学仿真Composites FEM

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