首页/文章/ 详情

【新文速递】2024年5月24日复合材料SCI期刊最新文章

9天前浏览593

   

今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 5 篇,Composites Science and Technology 2 篇

Composite Structures

New insights into folding tape-spring

Tian-Wei Liu, Jiang-Bo Bai, Nicholas Fantuzzi

doi:10.1016/j.compstruct.2024.118225

折叠带弹簧的新见解

The tape-spring is widely used in aerospace, mechanical, and civil engineering due to its unique mechanical properties and compact size. This paper aims to establish a new analytical model to more accurately predict the folding behavior of the tape-spring, including the geometric configuration, folding moment versus longitudinal curvature curve, peak moment, and propagation moment. This model comprehensively considers the influence of stretching strain energy and bending strain energy on the total strain energy, and determines the folding behavior of the tape-spring through the minimum energy principle. The proposed analytical model was compared with Wuest’s model, Yee’s model, and Yao’s model. Experiments of tape-springs made from two different materials were utilized for validation. The study shows that the proposed model has the highest prediction accuracy compared with the classical models, with the error of approximately 10%. The reason for the significant difference in the prediction results between the proposed model and Yao’s model was given, and the relationship between stretching strain energy and bending strain energy during the folding process of the tape-spring was analyzed. The proposed model has broader applicability than classical models and provides new insights and solutions for accurate prediction of the folding behavior of the tape-spring.

带式弹簧以其独特的力学性能和紧凑的尺寸在航空航天、机械和土木工程中得到广泛应用。本文旨在建立一个新的解析模型,以更准确地预测带式弹簧的折叠行为,包括几何构型、折叠弯矩与纵向曲率曲线、峰值弯矩和传播弯矩。该模型综合考虑了拉伸应变能和弯曲应变能对总应变能的影响,通过最小能量原理确定了带式弹簧的折叠行为。将提出的分析模型与Wuest的模型、Yee的模型和Yao的模型进行比较。用两种不同材料制成的带式弹簧进行了实验验证。研究表明,与经典模型相比,该模型具有最高的预测精度,误差约为10%。给出了该模型与Yao模型预测结果存在显著差异的原因,分析了带式弹簧折叠过程中拉伸应变能与弯曲应变能之间的关系。该模型具有比传统模型更广泛的适用性,为准确预测带式弹簧的折叠行为提供了新的见解和解决方案。


Multi-feature parallel topology optimization of fiber-reinforced coated structures based on a dual variable scale filtering method

Xuefei Yang, Liang Gao, Hao Li

doi:10.1016/j.compstruct.2024.118227

基于双变尺度滤波的纤维增强涂层结构多特征并行拓扑优化

Due to their outstanding mechanical properties, fiber-reinforced polymer composite (FRPC) structures have become a prominent research topic. Yet, to surpass existing performance limits, their design potential should be expanded beyond conventional empirical methods. Moreover, because of the high manufacturing costs, the protection of FRPC structures should be considered in the design phase to extend their service life. In this paper, we introduce an innovative configuration wherein metal coatings are strategically applied to the surfaces of FRPC structures. This technique aims to protect the internal matrix and fiber materials, and to inhibit the interlaminar delamination of composite laminates. Then, a corresponding full-scale topology optimization framework is built based on a density-based method. The coating, matrix, and fiber materials are considered collectively, avoiding issues such as excessive computation, non-convex optimization, and fiber discontinuity. Furthermore, a dual variable scale filtering (DVSF) method and its simplified scheme are presented to optimize coating thickness based on the physical information obtained from finite element analysis. Meanwhile, the co-evolution of solid topology and fiber morphology, driven by algorithms, facilitates the parallel optimization of multiple geometric features. Several typical examples, including wing ribs, are provided to illustrate the effectiveness and superiority of our approach, highlighting its engineering relevance.

由于其优异的力学性能,纤维增强聚合物复合材料(FRPC)结构已成为一个突出的研究课题。然而,为了超越现有的性能限制,它们的设计潜力应该超越传统的经验方法。此外,由于制造成本高,在设计阶段应考虑对FRPC结构的保护,以延长其使用寿命。在本文中,我们介绍了一种创新的配置,其中金属涂层战略性地应用于FRPC结构的表面。该技术旨在保护内部基体和纤维材料,抑制复合材料层间分层。然后,基于基于密度的方法构建了相应的全尺寸拓扑优化框架。涂层、基体和纤维材料被综合考虑,避免了过多的计算、非凸优化和纤维不连续等问题。在此基础上,提出了基于有限元物理信息的双变尺度滤波(DVSF)方法及其简化方案来优化涂层厚度。同时,在算法的驱动下,固体拓扑和光纤形态的协同演化为多个几何特征的并行优化提供了便利。提供了几个典型的例子,包括翼肋,以说明我们的方法的有效性和优越性,突出其工程相关性。


Mechanical behavior of STF impregnation and anti-impact performances of Kevlar and UHMPWEF fabric impregnations

Enling Tang, Hongrun Tan, Ruizhi Wang, Chuang Chen, Yafei Han, Mengzhou Chang, Kai Guo, Liping He

doi:10.1016/j.compstruct.2024.118228

STF浸渍的力学行为及Kevlar和UHMPWEF织物浸渍的抗冲击性能

STF-impregnated Kevlar and ultra-high molecular weight polyethylene (UHMWPEF) fabric-impregnated bodies were prepared by using mass fraction of 34 % SiO2 with a particle size of 100 nm and PEG400 as dispersion and dispersant, respectively. When two kinds of fiber fabrics were impregnated by STF, the tensile, single fiber pull-out and single fiber tensile loads of Kevlar fabric-impregnated increased 26.63 %, 155.55 %, and 98.64 %, respectively. However, the tensile load, monofilament pull-out load and monofilament tensile load of the UHMWPEF fabric-impregnated body increased 100.14 %, 729.03 % and 51.61 %, respectively. Kevlar fiber fabric impregnated by ultrasonic vibration and smearing STF absorbs more steel projectile’s kinetic energies of 52.3 % and 27.43 % than that of the original fiber fabric, respectively. UHMPWEF fabric impregnated by using ultrasonic vibration and smearing increased 65.56 % and 47.73 % than the original fabric absorbing steel projectile’s kinetic energy. Based on the Scanning Electron Microscope (SEM) observation of the fiber fabric surface, it was found that the connection between the fibers was significantly strengthened after the STF impregnation treatment. When the fabric was subjected to impact load, STF played an important role in transmitting load and increasing friction.

采用质量分数为34 %、粒径为100 nm的SiO2和PEG400分别作为分散剂和分散剂,制备了stf浸渍凯夫拉纤维和超高分子量聚乙烯(UHMWPEF)织物浸渍体。两种纤维织物经STF浸渍后,其拉伸载荷、单纤维拉拔载荷和单纤维拉伸载荷分别提高26.63 %、155.55 %和98.64 %。而UHMWPEF织物浸渍体的拉伸载荷、单丝拉拔载荷和单丝拉伸载荷分别提高了100.14 %、729.03 %和51.61 %。超声振动浸渍和涂抹STF的Kevlar纤维织物比原纤维织物吸收钢弹的动能分别增加52.3% %和27.43% %。超声振动和涂布浸渍后的超高强度wef织物对钢弹动能的吸收比原织物提高了65.56 %和47.73 %。通过对纤维织物表面的扫描电镜(SEM)观察发现,经STF浸渍处理后,纤维之间的连接明显加强。当织物受到冲击载荷时,STF在传递载荷和增加摩擦方面发挥了重要作用。


Composites Part A: Applied Science and Manufacturing

Toughening of self-reinforced PLA films using PLA nanofiber mats and oriented PLA tapes as interlayers

Guiling Niu, Yinping Tao, Rongmin Zhang, Xin Feng, Hua Deng, Musu Ren, Jinliang Sun, Ton Peijs

doi:10.1016/j.compositesa.2024.108267

 

用聚乳酸纳米纤维垫和定向聚乳酸带作夹层的自增强聚乳酸薄膜增韧研究

Self-reinforced poly(lactic acid) composite (SRPLA) offers advantages in terms of convenient recycling due to its mono-material nature, potential biodegradability, and biocompatibility. Moreover, SRPLA has shown the ability to overcome the inherent brittleness of PLA. To deepen our understanding of how different types of reinforcements and process parameters can affect tensile properties, particularly tensile toughness, SRPLA has been prepared based on oriented tapes (ot-SRPLA) as well as nanofiber mats (nf-SRPLA) using a film-stacking and hot-compaction approach. A considerable improvement was observed in tensile strength, modulus, and toughness at the optimum consolidation temperature and time. Specifically, the tensile toughness of nf-SRPLA increased approximately threefold at a very low nanofiber loading of 0.56 wt%, while the toughness of ot-SRPLA more than doubled at a tape mass fraction of 36 wt%. In terms of toughening mechanisms, the presence of the nanofibers slowed down crack propagation through crack branching, deviation, and fiber bridging in nf-SRPLA, whereas the predominant toughening mechanisms were interlayer debonding and tape pull-out for ot-SRPLA.

自增强聚乳酸复合材料(SRPLA)由于其单材料性质、潜在的生物降解性和生物相容性,在方便回收方面具有优势。此外,SRPLA还显示出克服PLA固有脆性的能力。为了加深我们对不同类型的增强剂和工艺参数如何影响拉伸性能,特别是拉伸韧性的理解,我们使用薄膜堆积和热压实方法制备了基于定向带(ot-SRPLA)和纳米纤维垫(nf-SRPLA)的SRPLA。在最佳固结温度和时间下,拉伸强度、模量和韧性均有显著提高。具体来说,在0.56 wt%的极低纳米纤维负载下,nf-SRPLA的拉伸韧性增加了约三倍,而在36 wt%的带质量分数下,t- srpla的韧性增加了一倍以上。在增韧机制方面,纳米纤维的存在通过裂缝分支、偏离和纤维桥接减缓了nf-SRPLA的裂纹扩展,而在t- srpla中,主要的增韧机制是层间脱粘和带拔出。


Unraveling chemical and rheological mechanisms of self-healing with EMAA thermoplastics in fiber-reinforced epoxy composites

Alexander D. Snyder, Jack S. Turicek, Charles E. Diesendruck, Russell J. Varley, Jason F. Patrick

doi:10.1016/j.compositesa.2024.108271

纤维增强环氧复合材料中EMAA热塑性塑料自愈的化学和流变机制研究

Interlaminar delamination is a prevalent and insidious damage mode limiting the mechanical integrity and lifetime of fiber-reinforced composites. Conventional resolution involves over-design, laborious inspection, and repair/replacement at cost to the economy and environment. Self-healing via in situ thermal remending of thermoplastic interlayers offers a promising solution. However, better understanding of the healing agent and related mechanisms is necessary to tailor healing performance. Here, we compare non-neutralized (copolymer) and metallic-ion neutralized (ionomer) poly(ethylene-co-methacrylic acid) (EMAA) thermoplastics for healing interlaminar fracture. We reveal (i) how EMAA chemistry affects the interfacial reactions driving healing and (ii) the influence of molten viscosity on repair efficiency. At fixed viscosity, higher methacrylic acid content, chain mobility, and lower neutralization positively influence healing, where lower melt viscosity at fixed temperature improves delamination recovery. Thus, this study deepens scientific understanding of key variables for healing interlaminar fracture with EMAA, providing new insight for the design of multifunctional composites.

层间分层是一种普遍存在的潜在损伤模式,限制了纤维增强复合材料的力学完整性和使用寿命。传统的解决方案涉及过度设计,费力的检查,以及以经济和环境为代价的维修/更换。通过热塑性夹层的原位热修复提供了一个很有前途的解决方案。然而,更好地了解愈合剂和相关机制对于调整愈合性能是必要的。在这里,我们比较了非中和(共聚物)和金属离子中和(离聚体)聚乙烯-共甲基丙烯酸(EMAA)热塑性塑料愈合板间骨折。我们揭示了(i) EMAA化学如何影响驱动愈合的界面反应和(ii)熔融粘度对修复效率的影响。在固定粘度下,较高的甲基丙烯酸含量、链迁移率和较低的中和作用对愈合有积极影响,其中固定温度下较低的熔体粘度有助于分层恢复。因此,本研究加深了对EMAA愈合椎间骨折关键变量的科学认识,为多功能复合材料的设计提供了新的见解。


Assessing the impact of accelerated weathering on the mechanical properties of a flax/epoxy composite: A study on tensile performance and drop-weight impact

Abdelhadi Hadj-Djilani, Habiba Bougherara, Redouane Zitoune, Lotfi Toubal

doi:10.1016/j.compositesa.2024.108277

 

评估加速风化对亚麻/环氧复合材料力学性能的影响:拉伸性能和落锤冲击的研究

This study examined how UV exposure and humidity (accelerated weathering) affect flax/epoxy composites. Three configurations (unidirectional, cross-ply, and quasi-isotropic) were aged for 1200 h. Tensile and impact tests revealed significant property degradation in all configurations. Tensile strength, modulus, and strain all decreased after aging. Young’s modulus dropped by 8–11.5%, stress by 12.2–18%, and strain by 10–18.59%. Impact tests showed a decrease in tolerated impact load (6–10%) but an increase in absorbed energy (7–12%). This suggests more surface damage after aging. These results highlight the substantial influence of environmental factors on the long-term performance of flax/epoxy composites.

本研究考察了紫外线暴露和湿度(加速风化)对亚麻/环氧复合材料的影响。三种结构(单向、交叉铺层和准各向同性)老化1200小时。拉伸和冲击试验显示,所有结构的性能都有明显的退化。时效后,拉伸强度、模量和应变均下降。杨氏模量下降8-11.5%,应力下降12.2-18%,应变下降10-18.59%。冲击试验表明,耐冲击载荷降低(6-10%),但吸收能量增加(7-12%)。这表明老化后表面损伤更大。这些结果凸显了环境因素对亚麻/环氧复合材料长期性能的实质性影响。


Effect of alkaline treatment on hard vegetable shells on the properties of biobased abrasive wheels

Narcisse Defo, Omar Harzallah, Rodrigue Nicodème Tagne Sikame, Ebenezer Njeugna, Sophie Bistac

doi:10.1016/j.compositesa.2024.108278

蔬菜硬壳碱性处理对生物基砂轮性能的影响

One of challenges in composites research is to improve the quality of the interface fillers-matrix. The aim of this study was to evaluate the effect of sodium hydroxide (NaOH) treatment of coconut shells and palm kernel shells on the properties of wheels made. Shells were treated at concentrations of 1 %, 5 % and 10 % for 90 min before being used as abrasive grains to reinforce an epoxy matrix. The thermal degradation of shells was analyzed and the morphological study shows that the treatment modifies the surface of grains. The treatment led to a reduction in the water absorption rate of more than 10 % and the porosity of the grinding wheels of around 15 %. Statistical analysis showed that the treatment improved the material removal rate and wear resistance. The wheels treated with a concentration of 1 % gave better results with removal rates of 160 mg/s and wear rates of 3.86E-05 cm3/N.m.

提高界面填料-基体的质量是复合材料研究面临的挑战之一。本研究的目的是评价氢氧化钠(NaOH)处理椰子壳和棕榈仁壳对车轮性能的影响。壳在1%、5%和10%的浓度下处理90分钟,然后用作磨粒增强环氧基。对壳的热降解进行了分析,形态学研究表明,处理改变了晶粒表面。处理后的砂轮吸水率降低10%以上,孔隙率降低15%左右。统计分析表明,该处理提高了材料去除率和耐磨性。以1%的浓度处理的车轮效果较好,去除率为160 mg/s,磨损率为3.86E-05 cm3/N.m。


Mechanically robust, stretchable and environmentally adaptable organohydrogels with cross-linked fibrous structure for sensory artificial skins

Kexuan Wang, Bohui Zheng, Ping Wu, Jialiang Lai, Hongli Zhang, Weifeng Zhao, Xilang Jin, Aijie Ma, Weixing Chen, Hanbin Liu, Hongwei Zhou

doi:10.1016/j.compositesa.2024.108274

具有交联纤维结构的机械坚固,可拉伸和环境适应性强的有机水凝胶,用于感官人造皮肤

Hydrogels are promising materials for fabricating sensory artificial skins (SASs), but their mechanical properties and environment adaptability are often limited, leading to restricted performances of SASs. In this work, mechanically robust, stretchable and environment adaptable organohydrogels with cross-linked fibrous structure are designed and constructed. The organohydrogels are prepared by introducing doped polyaniline (PANI) into cross-linked fibrous mats of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA). Cross-linked PAA-PVA mat works as skeleton to account for the mechanical robustness while PANI serves as the conductive component to achieve mechanosensing functionality. Due to the unique structure, the resultant organohydrogels, being denoted as PAA-PVA/PANI organohydrogels, exhibit high tensile strength (5.06MPa), stretchability, fatigue resistance and excellent environment adaptability (anti-freezing, anti-drying and swelling resistance). SASs of such organohydrogels have achieved a gauge factor of 1.81, a sensing range of 0–70 %, a response time of 0.28 s and a reversible sensing in more than 2,000 cycles. In addition, SASs are further attempted in monitoring diverse human motions and physiological activities, such as joint bending, muscle motion and pulse. Overall, this work has provided promising soft materials for future SASs that work properly under complicated environmental conditions.

水凝胶是一种很有前途的感官人造皮肤材料,但其力学性能和环境适应性往往受到限制,导致其性能受到限制。在这项工作中,设计和构建了具有交联纤维结构的机械坚固,可拉伸和环境适应性强的有机水凝胶。将掺杂的聚苯胺(PANI)引入聚丙烯酸(PAA)和聚乙烯醇(PVA)交联纤维垫中制备有机水凝胶。交联PAA-PVA垫作为骨架,以说明机械稳健性,而聚苯胺作为导电组件,以实现机械传感功能。由于其独特的结构,所制得的有机水凝胶为PAA-PVA/PANI有机水凝胶,具有较高的抗拉强度(5.06MPa)、拉伸性、抗疲劳性和优异的环境适应性(抗冻、抗干燥、抗膨胀)。该有机水凝胶的SASs测量系数为1.81,传感范围为0-70 %,响应时间为0.28 s,可实现2000多次循环的可逆传感。此外,SASs还被进一步用于监测人体的各种运动和生理活动,如关节弯曲、肌肉运动和脉搏。总的来说,这项工作为未来在复杂环境条件下正常工作的SASs提供了有前途的软材料。


Composites Science and Technology

Synergistic Enhancement of Strength and Toughness through Meta-Biomimetic Design: Integrating Crossed-Lamellar and Bouligand Microstructures

Xiaofang Zhang, Yanan Yuan

doi:10.1016/j.compscitech.2024.110668

 

通过元仿生设计协同增强强度和韧性:整合交叉片层和Bouligand微观结构

The development of fiber-reinforced polymer (FRP) composites, striking a balance between high strength and toughness, is a pressing requirement for the contemporary aerospace industry. Regarding the design of microstructures for enhancing strength and toughness, bionic crossed-lamellar and bouligand structures serve as noteworthy examples. However, individual biomimetic microstructures have approached the upper limit of their strengthening and toughening effects.This paper firstly proposed a “Meta-Biomimetic” design concept: hybridizing biological microstructures with defensive functionalities and those with offensive functionalities in mechanical design, aiming to achieve a metamaterial with both offensive and defensive capabilities. Namely this work retains the three-layer cross-lamellar microstructure of conch shells to stimulate subcritical damage for enhanced energy dissipation, while introducing a bouligand microstructure of lobster homarus americanus to increase the high load-bearing capacity at both tension and compression ends. The optimal design for enhancing the strength and toughness is the three-layer crossed-lamellar microstructure modified with a full bouligand structure, which increases strength and toughness simultaneously by more than 500% compared to natural structures. These studies are poised to not only steer the design of FRP microstructures towards enhanced strength and toughness but also furnish a foundation for interdisciplinary research in biomimetics within composite materials.

在高强度和高韧性之间取得平衡的纤维增强聚合物(FRP)复合材料的发展是当代航空航天工业的迫切要求。在提高强度和韧性的微结构设计方面,仿生交叉片层结构和土石结构是值得注意的例子。然而,单个仿生微观结构已经接近其强化和增韧效果的上限。本文首先提出了“Meta-Biomimetic”设计概念:将具有防御功能的生物微结构与具有进攻功能的生物微结构在机械设计上进行杂交,以实现兼有进攻和防御能力的超材料。即,本研究保留了海螺壳的三层交叉片层微观结构,以刺 激亚临界损伤,增强能量耗散,同时引入美洲大龙虾的土石结构,以提高其拉压两端的高承载能力。提高强度和韧性的最佳设计是采用全土石结构改性的三层交叉片层微观结构,与天然结构相比,强度和韧性同时提高500%以上。这些研究不仅将引导FRP微结构的设计朝着增强强度和韧性的方向发展,而且还将为复合材料仿生学的跨学科研究奠定基础。


High modulus carbon fiber based composite structural supercapacitors towards reducing internal resistance and improving multifunctional performance

Guocheng Qi, Jianxiong Wu, Bin Yao, Qian Cui, Liang Ren, Boming Zhang, Shanyi Du

doi:10.1016/j.compscitech.2024.110670

 

高模量碳纤维复合材料结构超级电容器,旨在降低内阻,提高多功能性能

Carbon fibers (CFs) based composite structural supercapacitors (CSSs) are promising multifunctional energy storage composites which can simultaneously realize load bearing and electricity storage. The device power is still low due to the high internal resistance of CSS. Herein, the CFs, electrolytes, monofunctional devices and multifunctional composite devices were investigated to show the attribution of the internal resistances. Both the normally used T300 CF and high modulus M55J CF fabrics were utilized. The electric in-plane and through-the-thickness resistances of CF fabric electrodes were characterized, respectively. The internal resistance of the monofunctional supercapacitor devices which were assembled using liquid electrolyte were evaluated considering the effects of CF sizing. The bicontinuous structural electrolytes (BSEs) composed of epoxy (EP) and ionic liquid (IL) were prepared as the multifunctional matrix of the CSSs. The chemical structure, thermal stability and ionic conductivity of the BSEs were assessed. The activated carbon (AC) loaded CFs and BSEs were used to fabricate the CSSs. Both the tensile and charge/discharge properties of the M55J CF CSSs were higher than those of the T300 CF CSSs. This work could provide new insights into the resistance attribution of CSS and how to simultaneously improve both mechanical and electrochemical performances of CSSs.

碳纤维复合结构超级电容器是一种很有前途的多功能储能复合材料,可同时实现承载和蓄电。由于CSS的内阻过高,导致设备功率仍然较低。本文研究了CFs、电解质、单功能器件和多功能复合器件的内阻属性。采用了常用的T300 CF和高模量M55J CF织物。对CF织物电极的面内电阻和透厚电阻进行了表征。考虑CF尺寸的影响,对液态电解液组装的单功能超级电容器器件的内阻进行了评价。制备了由环氧树脂(EP)和离子液体(IL)组成的双连续结构电解质(BSEs)作为多功能电解质的基体。评价了bse的化学结构、热稳定性和离子电导率。采用活性炭(AC)负载CFs和bse制备css。M55J CF CSSs的拉伸性能和充放电性能均高于T300 CF CSSs。该研究为进一步了解CSS的电阻属性以及如何同时提高CSS的力学和电化学性能提供了新的思路。



来源:复合材料力学仿真Composites FEM
ACTMechanical振动疲劳复合材料化学拓扑优化航空航天ADSUGUM裂纹材料储能仿生试验
著作权归作者所有,欢迎分享,未经许可,不得转载
首次发布时间:2024-11-14
最近编辑:9天前
Tansu
签名征集中
获赞 3粉丝 0文章 690课程 0
点赞
收藏
作者推荐

【新文速递】2024年3月16日复合材料SCI期刊最新文章

今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇Composite StructuresA fast polynomial-FE method for the vibration of the composite laminate quadrilateral plates and shells based on the segmentation strategyYiming Zhao, Ke Yuan, Bin Qin, Lumin Shen, Wang Zhonggangdoi:10.1016/j.compstruct.2024.118035基于分段策略的复合层压四边形板壳振动多项式-FE 快速方法The finite element method is widely applicable to various kinds of models. Nonetheless, as the size and frequency domain of the solving model increase, it encounters challenges related to high memory consumption and slow solution speed. To enhance the computational efficiency while preserving its existing advantages, this study incorporates the Jacobi polynomial with a segmentation strategy into the finite element method for addressing the vibration analysis of composite laminate quadrilateral flat and curved plates. In this method, the dynamic stiffness matrix of a finite element is multiplied on both sides by a matrix composed of Jacobi polynomial basis functions, thereby transforming the expression form of the dynamic stiffness matrix from FE form to meshless form and reducing its size. Additionally, the segmentation strategy is introduced to divide the model into multiple blocks, enhancing convergence and calculation efficiency by altering the sparsity pattern of the dynamic stiffness matrix. Convergence research, validation studies, limitations studies, and parametric studies are conducted. The method demonstrates evident advantages in computational efficiency for random surface quadrilateral models requiring dense mesh description while maintaining a certain level of accuracy.有限元法广泛适用于各种模型。然而,随着求解模型的大小和频域的增加,有限元法也遇到了内存消耗大、求解速度慢等难题。为了在保留其现有优势的同时提高计算效率,本研究在有限元方法中加入了雅可比多项式和分段策略,以解决复合材料层压四边形平板和曲面板的振动分析问题。在该方法中,有限元的动态刚度矩阵两边乘以雅可比多项式基函数组成的矩阵,从而将动态刚度矩阵的表达形式从有限元形式转换为无网格形式,并减小其大小。此外,还引入了分割策略,将模型分成多个区块,通过改变动态刚度矩阵的稀疏性模式来提高收敛性和计算效率。此外,还进行了收敛性研究、验证研究、局限性研究和参数研究。对于需要密集网格描述的随机曲面四边形模型,该方法在保持一定精度的同时,在计算效率方面具有明显优势。Composites Part A: Applied Science and ManufacturingGreen manufacturing process design for infusible acrylic resin composites: A data-guided life cycle management model incorporating material-process-property-energy-emission relationshipsYan Shen, Wutong Du, Xuelin Sui, Xinyue Liu, Ben Zhong Tang, Jinglei Yangdoi:10.1016/j.compositesa.2024.108146可灌注丙烯酸树脂复合材料的绿色制造工艺设计:数据引导的生命周期管理模型,包含材料-工艺-性能-能耗-排放关系This research targets the green manufacturing process design of novel liquid thermoplastic resin-based composites. First, curing cycles at various temperatures were explored via a two-stage determination. Energy consumption was recorded via power monitoring. Greenhouse gas (GHG) emissions from consumed electricity and polymerization were calculated to quantify the eco-impact. Moreover, the effect of curing conditions on mechanical properties was revealed. Results showed that sunbathing in the shadow could be a green manufacturing process with the shortest manufacturing cycle and almost no additional energy consumption. Notably, room-temperature polymerization for 24 h achieved the highest tensile modulus; isothermal curing at 40 °C for 3 h demonstrated superior tensile and flexural strength; and isothermal curing at 60 °C for 1.5 h obtained the greatest flexural modulus. Finally, this study constructed the “Material-Process-Property-Energy-emission” (MPPEE) relationships and provided a green manufacturing process design methodology for trading off between manufacturing efficiency, mechanical performance, and sustainability.本研究以新型液态热塑性树脂基复合材料的绿色制造工艺设计为目标。首先,通过两阶段测定法探索了不同温度下的固化周期。通过电力监控记录能源消耗。通过计算消耗的电力和聚合产生的温室气体(GHG)排放量,对生态影响进行量化。此外,还揭示了固化条件对机械性能的影响。结果表明,"阴影下的日光浴 "是一种绿色制造工艺,其制造周期最短,几乎没有额外的能源消耗。值得注意的是,室温聚合 24 小时可获得最高的拉伸模量;40 °C等温固化 3 小时可获得优异的拉伸和弯曲强度;60 °C等温固化 1.5 小时可获得最大的弯曲模量。最后,本研究构建了 "材料-工艺-性能-能源-排放"(MPPEE)关系,并提供了一种在制造效率、机械性能和可持续性之间进行权衡的绿色制造工艺设计方法。Composites Part B: EngineeringEfficient photocatalytic H2 evolution over NiMoO4/Twinned-Cd0.5Zn0.5S double S-scheme homo-heterojunctionsJingzhuo Tian, Xiaofei Cao, Tao Sun, Hui Miao, Zhong Chen, Wenhua Xue, Jun Fan, Enzhou Liudoi:10.1016/j.compositesb.2024.111389 NiMoO4/Twinned-Cd0.5Zn0.5S 双 S 型同质异质结上的高效光催化 H2 演化The effectiveness of charge transfer and separation between bulk phase and the interface is crucial for evaluating the performance of photocatalysts. In this study, NiMoO4 was employed to enhance the photocatalytic activity for hydrogen (H2) evolution in twinned Cd0.5Zn0.5S (T-CZS) homojunctions comprising of wurtzite Cd0.5Zn0.5S (WZ-CZS) and zinc blende Cd0.5Zn0.5S (ZB-CZS) with alternating arrangements. The investigation reveals that the introduction of NiMoO4 can lead to an increase of active sites for H2 evolution, a prolongation of charge carrier lifetime, and a decrease of H2 evolution overpotential. The H2 production rate of 8 wt% NiMoO4/T-CZS reaches up to 71.2 mmol h−1 g−1, while its apparent quantum efficiency (AQY) is 8.23% at 400 nm. The enhanced activity can be attributed to the synergistic effects of homojunctions and heterojunctions in NiMoO4/T-CZS. According to the density functional theory (DFT), photoelectric response, and radical trapping experimental analysis, the charge transfer between WZ-CZS and ZB-CZS in T-CZS, as well as NiMoO4 and T-CZS, both follow the S-scheme pathway under the influence of band bending, Coulombic force, and built-in electric field. This leads to an effective internal and interfacial charge separation in NiMoO4/T-CZS homo-heterojunctions, while maintaining their high reactivity. Additionally, the H2 evolution activity of T-CZS can also be increased in different degrees by various metal molybdates (MMoO4) including CoMoO4, Ag2MoO4, Bi2(MoO4)3, BaMoO4, ZnMoO4, and CdMoO4. The bulk and interfacial synergistic double S-scheme homo-heterojunctions in this study provide new insights for targeted solar driven H2 evolution engineering.体相和界面之间电荷转移和分离的有效性对于评估光催化剂的性能至关重要。本研究采用 NiMoO4 来提高孪晶 Cd0.5Zn0.5S(T-CZS)同质结中氢(H2)进化的光催化活性,该同质结由交替排列的钨锌态 Cd0.5Zn0.5S(WZ-CZS)和混合锌态 Cd0.5Zn0.5S(ZB-CZS)组成。研究发现,NiMoO4 的引入可以增加 H2 演化的活性位点,延长电荷载流子的寿命,降低 H2 演化的过电位。8 wt% NiMoO4/T-CZS 的 H2 产率高达 71.2 mmol h-1 g-1,在 400 纳米波长下的表观量子效率(AQY)为 8.23%。活性的增强可归因于 NiMoO4/T-CZS 中同结和异结的协同效应。根据密度泛函理论(DFT)、光电响应和自由基捕获实验分析,T-CZS 中的 WZ-CZS 和 ZB-CZS 之间以及 NiMoO4 和 T-CZS 之间的电荷转移均在带弯曲、库仑力和内置电场的影响下遵循 S 型途径。这导致了 NiMoO4/T-CZS 同质异质结中有效的内部和界面电荷分离,同时保持了其高反应活性。此外,各种金属钼酸盐(MMoO4)(包括 CoMoO4、Ag2MoO4、Bi2(MoO4)3、BaMoO4、ZnMoO4 和 CdMoO4)也能不同程度地提高 T-CZS 的 H2 演化活性。本研究中的块体和界面协同双 S 型同质异质结为有针对性的太阳能驱动 H2 演化工程提供了新的见解。Composites Science and TechnologyIn-situ growth of CuS on polyimide film to construct dense and continuous network: Achieving excellent electrothermal and EMI shielding performanceLingtong Li, Zhiheng Zhao, Yang Pan, Minhang Chen, Yang Zhang, Renke Li, Hong Wu, Shaoyun Guodoi:10.1016/j.compscitech.2024.110543 在聚酰亚胺薄膜上原位生长 CuS,构建致密连续的网络:实现优异的电热和电磁干扰屏蔽性能The performance of the electrothermal film is generally determined by conductive filler network. However, it is still challenging to construct a dense network of conductive fillers in the electrothermal film. In this work, we develop a simple and efficient method to construct a dense and continuous network via in-situ growth of CuS nanosheets on the surface of polyimide (PI) film with stable interfacial bonding. The obtained PI@CuS electrothermal film is further packaged by commercially available PTFE and PI tapes to achieve desirable surface hydrophobic self-cleaning function and stability for the use in different environments. By tuning the network density of CuS nanosheets, it imparts excellent electrothermal conversion efficiency and cycling stability to the PI@CuS film, whose surface temperature could rapidly ramp up over 200 °C at 8 V. The film also exhibits excellent photothermal performance, reaching close to 100 °C at 100 mW/cm2. The anti-icing/de-icing experiment shows that the icing time is prolonged significantly at low temperature and the melting time is reduced dramatically. Furthermore, the PI@CuS film also exhibits outstanding electromagnetic interference (EMI) shielding effectiveness of 57.1 dB with a thickness of only 80 μm, and excellent tensile strength of over 90 MPa. The in-situ growth strategy provides a novel route for the fabrication of the electrothermal film with excellent overall performance.电热膜的性能通常取决于导电填料网络。然而,在电热膜中构建致密的导电填料网络仍然具有挑战性。在这项工作中,我们开发了一种简单而高效的方法,通过在聚酰亚胺(PI)薄膜表面原位生长 CuS 纳米片,在稳定的界面键合下构建致密而连续的网络。得到的 PI@CuS 电热膜再用市售的聚四氟乙烯(PTFE)和聚酰亚胺(PI)胶带包装,以获得理想的表面疏水自清洁功能和稳定性,从而可在不同环境中使用。通过调整 CuS 纳米片的网络密度,PI@CuS 薄膜具有出色的电热转换效率和循环稳定性,在 8 V 电压下,其表面温度可迅速升至 200 ℃ 以上。该薄膜还具有出色的光热性能,在 100 mW/cm2 的条件下,温度可接近 100 °C。抗结冰/除冰实验表明,低温下结冰时间明显延长,熔化时间显著缩短。此外,PI@CuS 薄膜还具有出色的电磁干扰(EMI)屏蔽效果,厚度仅为 80 μm,屏蔽效果却高达 57.1 dB,抗拉强度超过 90 MPa。原位生长策略为制造具有优异综合性能的电热膜提供了一条新途径。来源:复合材料力学仿真Composites FEM

未登录
还没有评论
课程
培训
服务
行家
VIP会员 学习 福利任务 兑换礼品
下载APP
联系我们
帮助与反馈