今日更新:Composite Structures 1 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 1 篇
Energy absorption characteristics of modular assembly structures under quasi-static compression load
Qiqi Li, Weijun Wang, Hailun Tan, Xiangyun Long, Fang Wang, Lin Hu
doi: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。
Large deformation behavior and energy absorption of rotating square auxetics
Fereshteh Hassani, Zia Javanbakht, Sardar Malek
doi: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 validation
Thuan Ho-Nguyen-Tan, Min-Hyeok Jeon, Kyung Seok Jung, Jaesang Yu, Minkook Kim, Soon Ho Yoon
doi: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 Augmentation
Xuan Li, Xiangyi Liao, Zhenzhen Jia, Shuaiyin Liu, Ping Li, Li Li, Wei Zhang, Xufeng Niu, Yubo Fan
doi: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 composites
Junjie Luo, Ke Zou, Quantian Luo, Qing Li, Guangyong Sun
doi: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。
“Dual-armor” strategy to prepare multifunctional carbonyl iron particle with corrosion resistance, self-healing and high microwave absorbing performances
Kaka Li, Junbo Ge, Dongjie Zhang, Ruoxi Zhao, Chao Wu, Zhongjun Cheng, Zhimin Xie, Yuyan Liu
doi: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。