今日更新:Composite Structures 2 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 2 篇
Low-velocity impact (LVI) and compression after impact (CAI) of Double-Double composite laminates
Peyman Shabani, Lucy Li, Jeremy Laliberte
doi:10.1016/j.compstruct.2024.118615
双层复合材料层合板的低速冲击(LVI)和冲击后压缩(CAI)
Tailorability is a key advantage of fiber-reinforced composites over other material systems. While tailoring a single isolated laminate is relatively simple, challenges arise when designing larger integrated components while ensuring compatibility between laminates and avoiding sharp changes in local stiffness. The innovative Double-Double (DD) laminate design method simplifies the optimization and processing of laminates by incorporating 4-ply building blocks consisting of +ϕ, −ϕ, +ψ, and −ψ ply orientations. As a relatively new concept, DD laminate design requires careful assessment to ensure that the performance of DD laminates is equivalent to that of conventional designs. The current study compares impact damage tolerance of quadriaxial (QUAD) laminates consisting of 0°, 90°, and ±45° ply orientations with equivalent DD laminates under Low-Velocity Impact (LVI) and Compression After Impact (CAI) loadings. To this end, a validated three-dimensional high-fidelity finite element model capable of capturing fiber breakage, splitting, kinking, as well as matrix cracking and delamination, was used. A computer tool was developed to identify equivalent DD laminates and to find the best stacking sequence for achieving layup homogenization. Three equivalent DD laminates were selected for the [0/45/90/−45]4s. The first laminate had an equal in-plane stiffness [A] matrix ([67.5/–22.5/22.5/−67.5]8T), the second laminate had an equal flexural stiffness [D] matrix ([64.5/−17/17/−64.5]8T), and the third laminate ([65.5/−18.5/18.5/−65.5]8T) had a similar [D] matrix while keeping the difference between each element of [A] matrices below 10 %. The results indicate that the QUAD laminates can be replaced by equivalent DD without compromising impact damage tolerance while benefiting from the improved design and manufacturing ease of the DD laminate configuration.
可定制性是纤维增强复合材料相对于其他材料系统的一个关键优势。虽然定制单个隔离层压板相对简单,但在设计更大的集成组件时,要确保层压板之间的兼容性并避免局部刚度的急剧变化,就会遇到挑战。创新的Double-Double (DD)层压板设计方法通过结合由+ φ, - φ, +ψ和- ψ层方向组成的4层构建块,简化了层压板的优化和加工。作为一个相对较新的概念,DD层压板设计需要仔细评估,以确保DD层压板的性能与传统设计相当。目前的研究比较了由0°、90°和±45°铺层组成的四轴(QUAD)层压板与等效DD层压板在低速冲击(LVI)和冲击后压缩(CAI)载荷下的冲击损伤容限。为此,使用了一个经过验证的三维高保真有限元模型,该模型能够捕捉纤维断裂、劈裂、扭结以及基体开裂和分层。开发了一种计算机工具来识别等效的DD层压板,并找到达到分层均匀化的最佳堆叠顺序。为[0/45/90/−45]4s选择了三个等效的DD层压板。第一个层压板具有相同的面内刚度[A]矩阵([67.5/ -22.5/22.5 / - 67.5]8T),第二个层压板具有相同的弯曲刚度[D]矩阵([64.5/ - 17/17/ - 64.5]8T),第三个层压板([65.5/ - 18.5/18.5/ - 65.5]8T)具有相似的[D]矩阵,但[A]矩阵的每个元素之间的差异小于10 %。结果表明,在不影响冲击损伤容限的情况下,可以用等效的DD代替QUAD层压板,同时受益于DD层压板结构的改进设计和制造方便性。
Low-velocity impact resistance behaviors of bionic hybrid-helicoidal composite laminates
Yabin Deng, Hongyong Jiang, Yiru Ren
doi:10.1016/j.compstruct.2024.118614
仿生混合-螺旋复合材料层合板的低速抗冲击性能
The exoskeleton of the Homarus americanus lobster feature a hybrid-helicoidal structure of chitin-protein fibers, with distinct helicoidal configurations in the exocuticle and endocuticle, exhibiting strong impact resistance. Taking inspiration from this biological structure, combined with single-helicoidal and double-helicoidal structures, various helicoidal configurations of composite laminates were designed. Both linear and nonlinear helicoidal angles, including sinusoidal and exponential configurations, were considered. The interlaminar and intralaminar damage mode were adopted to simulate material damage initiation and evolution. The effect of helicoidal angles, position, thickness and angle variations of endocuticle on low-velocity impact resistance was analyzed, revealing the damage mechanisms of bio-inspired laminates. The results show that bio-inspired hybrid helicoidal structures with special features could significantly enhance the impact resistance of composites, with laminates featuring sinusoidal-exponential double helicoidal structures showing superior performance. Sinusoidal configurations, being less prone to penetration, are more suitable for the exocuticle. The introduction of double-helicoidal configurations could enhance the toughness and strength of the structure. This studying deepened an understanding of failure mechanisms of bio-inspired helicoidal composite laminates under low-velocity impact and provide a design strategies for developing high-performance, impact-resistant composite materials.
美洲小龙虾的外骨骼具有几丁质蛋白纤维的混合螺旋结构,在外表皮和鞘内具有明显的螺旋构型,具有较强的抗冲击性。以这种生物结构为灵感,结合单螺旋和双螺旋结构,设计了多种螺旋结构的复合层压板。考虑了线性和非线性螺旋角,包括正弦和指数构型。采用层间和层内损伤模式模拟材料损伤的起裂和演化过程。分析了螺旋角度、内针位置、内针厚度及夹角变化对仿生层合板低速抗冲击性能的影响,揭示了仿生层合板的损伤机理。结果表明,具有特殊特征的仿生混合螺旋结构可以显著提高复合材料的抗冲击性能,其中正弦-指数双螺旋结构的层压板表现出优异的性能。正弦结构,不容易渗透,更适合于外表皮。引入双螺旋结构可以提高结构的韧性和强度。该研究加深了对仿生螺旋复合材料层合板在低速冲击下失效机理的理解,为开发高性能、抗冲击复合材料提供了设计策略。
Microstructure evolution and enhanced mechanical properties of CF/Mg composites with optimized fiber/matrix interfacial adhesion
Jiaming Liu, Xi Yang, Bowen Dong, Shichao Liu, Yubo Zhang, Guoqun Zhao, Tongmin Wang, Tingju Li
doi:10.1016/j.compositesb.2024.111852
纤维/基体界面黏附优化的CF/Mg复合材料微观结构演变及力学性能增强
In this study, the optimal carbon fiber/matrix (CF/matrix) interfacial adhesion was explored by tailoring sintering pressures, aiming to enhance the ultimate tensile strength (UTS) of CF/Mg composites. With increasing the pressure, the interfacial shear strength (IFSS) gradually increased from 28.8 MPa to 43.6 MPa. Remarkably enhanced UTS (152 MPa) of the composite was achieved, which was 120.3% higher than that of the matrix, through optimizing the IFSS to 39.7 MPa. Correspondingly, the main failure mechanism was fiber pulling-out and direct fiber-cutting. Whereas, excessive IFSS (43.6 MPa) deceased the UTS of the composite, with the dominant failure mechanism of direct fiber-cutting.
本研究通过调整烧结压力,探索碳纤维/基体(CF/matrix)界面的最佳粘附性,以提高CF/Mg复合材料的极限抗拉强度(UTS)。随着压力的增大,界面抗剪强度(IFSS)由28.8 MPa逐渐增大到43.6 MPa。通过优化IFSS为39.7 MPa,复合材料的抗压强度显著提高至152 MPa,比基体的抗压强度提高了120.3%。相应的,主要破坏机制为纤维拔出和纤维直接切割。而过大的IFSS (43.6 MPa)破坏了复合材料的UTS,其主要破坏机制是直接纤维切割。
3D printing enhanced piezoelectricity of MXene/P(VDF-TrFE) composites for energy harvesting and force sensing
Ceng Li, Ziyue Huang, Liang Zhang, Zifei Song, Ying Chen, Xiangwu Chang, Penghao Hu
doi:10.1016/j.compscitech.2024.110881
3D打印增强MXene/P(VDF-TrFE)复合材料的压电性,用于能量收集和力传感
In pursuit of advanced self-powered wearable devices, piezoelectric materials have aroused great attention due to their stable energy harvesting ability from surroundings. However, traditional piezoelectric polymer-based nanogenerators necessitate a high-energy process to align the dipoles of the polymer, which is cumbersome, expensive, and could even lead to material deterioration. To address this challenge, we present a composite strategy with self-poling capability enabled by the extrusion-based 3D printing. MXene nanosheets were introduced into the fluoropolymer poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) to provide strong hydrogen bonding as anchors. Under the shear stress generated by the extrusion process, the alignment of the dipoles was realized without additional treatment. The resulting piezoelectric nanogenerator exhibits an open-circuit voltage of 5.5 V, a short-circuit current of 1.1 μA, and the output power density of 68 μWcm-3 under the force of 22 N and a frequency of 2 Hz. A self-powered sensor was assembled and demonstrated high sensitivity for human motions and facial expressions. Moreover, the 3D-printed piezoelectric composites present good flexibility, which is a crucial property for wearable devices. With the free design capabilities of the 3D printing technology, this strategy may pave the way for customized and feasible processing of high-performance piezoelectric nanogenerators and force sensors.
在追求先进的自供电可穿戴设备的过程中,压电材料因其稳定的能量收集能力而备受关注。然而,传统的基于压电聚合物的纳米发电机需要一个高能量的过程来排列聚合物的偶极子,这既麻烦又昂贵,甚至可能导致材料变质。为了应对这一挑战,我们提出了一种复合策略,该策略具有基于挤压的3D打印实现的自极点能力。将MXene纳米片引入到含氟聚合物聚偏氟乙烯-共三氟乙烯(PVDF-TrFE)中,作为锚点提供强氢键。在挤压过程产生的剪切应力作用下,偶极子的排列无需额外处理即可实现。该压电纳米发电机在22 N的力和2 Hz的频率下,开路电压为5.5 V,短路电流为1.1 μA,输出功率密度为68 μWcm-3。组装了一个自供电传感器,并证明了对人体动作和面部表情的高灵敏度。此外,3d打印的压电复合材料具有良好的柔韧性,这是可穿戴设备的关键特性。利用3D打印技术的自由设计能力,这一策略可能为高性能压电纳米发电机和力传感器的定制化和可行加工铺平道路。
“Reinforced Concrete” Design of Robust Mineralized Cellulose Composite with Multilayered Structure for Efficient CO2 Capture and Passive Radiative Cooling Ability
Chengling Huang, Hou-Yong Yu, Guozhuo Chen, Yiqi Liao
doi:10.1016/j.compscitech.2024.110886
具有高效二氧化碳捕获和被动辐射冷却能力的多层坚固的矿化纤维素复合材料的“钢筋混凝土”设计
The construction industry promotes the economic development of the country by addressing society’s housing needs. However, the industry’s energy consumption and carbon dioxide (CO2) emissions are the primary contributors to global warming. Traditional building materials are no longer capable of meeting the requirements of sustainable development, while natural cellulose can be used as a new type of carbon capture construction material. Inspired by the “reinforced concrete” methodology, a mineralized cellulose composite (ML-CCM) was fabricated through a strategy of vacuum filling and in-situ mineralization, resulting in a composite with a multi-level structure (a natural microporous 3D scaffold loofah as “rebar” and cellulose filler as “cement” are staggered in the composite). The resultant ML-CCM1 exhibited a significantly high flexural strain (approximately 215.9% of that of cellulose composite without loofah) because of the 3D scaffold loofah acting as a “rebar”. Furthermore, the composite possesses flame retardancy, superior thermal insulation at 90 °C, and passive radiative cooling performance due to the micro-nano ZnO particle in the “cement”. Moreover, the multi-level structure, consisting of pores and micro-nano particles, enables it to effectively adsorb CO2 and environment tobacco smoke. As a result, lifecycle assessments underscore the composite’s low Global Warming Potential. Therefore, this work reports a promising 3D bio-based composite with CO2 capture for energy conservation and carbon reduction in the construction industry.
建筑业通过解决社会的住房需求来促进国家的经济发展。然而,该行业的能源消耗和二氧化碳(CO2)排放是全球变暖的主要原因。传统的建筑材料已经不能满足可持续发展的要求,而天然纤维素可以作为一种新型的碳捕集建筑材料。受“钢筋混凝土”方法的启发,矿化纤维素复合材料(ML-CCM)通过真空填充和原位矿化的策略制成,从而形成具有多层结构的复合材料(天然微孔3D支架丝瓜络作为“钢筋”和纤维素填料作为“水泥”在复合材料中交错排列)。得到的ML-CCM1表现出显著的高弯曲应变(约为不含丝瓜丝瓜的纤维素复合材料的215.9%),因为3D支架丝瓜丝瓜起到“钢筋”的作用。此外,由于“水泥”中的微纳米氧化锌颗粒,该复合材料具有阻燃性,在90℃时具有优异的隔热性能,并且具有被动辐射冷却性能。此外,由孔隙和微纳颗粒组成的多层次结构使其能够有效吸附CO2和环境烟草烟雾。因此,生命周期评估强调了该复合材料的低全球变暖潜力。因此,这项工作报告了一种有前途的3D生物基复合材料,具有二氧化碳捕获,可用于建筑行业的节能和减碳。