今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 3 篇,Composites Science and Technology 1 篇
A multi-scale uncertainty analysis method based on the Hermite-Chebyshev polynomials for dynamic responses of FRP composite structures with hybrid uncertainties
Sheng-Yu Qian, Xiao-Yi Zhou, Neng-Wei Wang
doi:10.1016/j.compstruct.2024.118713
混合不确定性FRP复合材料结构动力响应的Hermite-Chebyshev多项式多尺度不确定性分析方法
Multi-scale hybrid uncertainties in material properties of FRP composites stemming from their manufacturing processes present significant challenges for dynamic analysis and reliability assessment. This paper proposes a multi-scale uncertainty surrogate model based on Hermite-Chebyshev polynomials. The relationship between micro- and macro-scale material properties is established using the Mori–Tanaka method. To demonstrate the efficacy of the proposed method, case studies are conducted on both a FRP wide-flange I-beam structure and a FRP truss bridge. Results indicate that this method accurately determines the probability density functions and cumulative distribution functions of natural frequencies and mode shapes. Notably, the method efficiently computes the upper and lower bounds of dynamic failure probability of FRP truss bridge with high numerical efficiency.
FRP复合材料性能的多尺度混合不确定性来源于其制造工艺,这对动态分析和可靠性评估提出了重大挑战。提出了一种基于Hermite-Chebyshev多项式的多尺度不确定性替代模型。采用Mori-Tanaka方法建立了材料微观和宏观性能之间的关系。为了证明该方法的有效性,对玻璃钢宽翼缘工字梁结构和玻璃钢桁架桥进行了实例研究。结果表明,该方法准确地确定了固有频率和振型的概率密度函数和累积分布函数。值得注意的是,该方法能够高效地计算FRP桁架桥梁动力破坏概率的上下界,具有较高的数值效率。
Numerical prediction of impact damage in thick fabric composite laminates
Niels van Hoorn, Sergio Turteltaub, Christos Kassapoglou, Wouter van den Brink
doi:10.1016/j.compstruct.2024.118726
厚织物复合材料层合板冲击损伤的数值预测
A simulation methodology for assessing the damage in thick fabric Carbon Fibre Reinforced Polymer (CFRP) composite laminates under low- and high-velocity impacts is presented. It encompasses steps for calibration, verification, and validation of the elastic and fracture material properties as well as determination of model parameters for the numerical simulations. Damage is modelled using a discrete fracture approach with cohesive interface elements that capture individual cracks occurring in and between plies. For computational efficiency, the method is implemented in a two-dimensional (2D) axi-symmetric model. Results from double-cantilever beam, end-notched flexure, and quasi-static indentation experiments align well with numerical simulations and serve to calibrate and verify the implementation of the discrete fracture approach. The methodology is extended to dynamic impact analysis to predict damage mechanisms, force–displacement histories, and is validated using test results. This methodology combines meaningful insight in the failure mechanisms with a manageable computational effort, achieving a factor 50 improvement compared to a benchmark. A parametric analysis summarised in failure maps relates damage mechanisms to impact energy, mass, and laminate thickness. The proposed methodology strikes a balance between computational efficiency and accuracy, making it a valuable tool for optimum design and certification of thick CFRP composite laminates under impact.
提出了一种评估厚织物碳纤维增强聚合物(CFRP)复合材料层合板在低速和高速碰撞下损伤的仿真方法。它包括步骤的校准,验证,并确认弹性和断裂材料的性能,以及确定模型参数的数值模拟。损伤建模采用离散断裂方法,具有内聚界面元素,可以捕获层内和层间发生的单个裂缝。为了提高计算效率,该方法采用二维轴对称模型实现。双悬臂梁、端缺口弯曲和准静态压痕实验的结果与数值模拟结果吻合良好,可用于校准和验证离散断裂方法的实现。该方法被扩展到动态冲击分析,以预测损伤机制、力-位移历史,并通过测试结果进行验证。这种方法结合了对故障机制的有意义的洞察和可管理的计算工作,与基准测试相比,实现了50倍的改进。失效图中总结的参数分析将损伤机制与冲击能量、质量和层压厚度联系起来。所提出的方法在计算效率和精度之间取得了平衡,使其成为在冲击下厚CFRP复合材料层合板优化设计和认证的有价值的工具。
Characterization of direct ink writing carbon fiber composite structures with serial sectioning and DREAM.3D
Kenneth M. Clarke, Michael Groeber, John Wertz, Andrew Abbott, Roneisha Haney, Michael Chapman
doi:10.1016/j.compstruct.2024.118730
直接墨水书写碳纤维复合材料结构的连续切片和DREAM.3D表征
Direct Ink Writing (DIW) combines the flexibility of 3D printing with increased material applications such as thermoset carbon fiber composites, ceramic composites, and metals. The usefulness of direct ink writing, like many additive manufacturing (AM) processes, remains limited for reasons ranging from quality control to lack of process parameter optimization. This study looks to introduce a methodology for characterizing direct ink written carbon fiber composites to facilitate exploration into the relationships between process parameters and material structure. The presented study utilized nine 3D specimens of direct ink writing carbon fiber composites printed with varying process parameters - speed differential, layer height, step-over distance, and nozzle diameter - as the data set. The data was collected with an automatic serial sectioning system, LEROY, from the Air Force Research Laboratory. The collected data was processed in DREAM.3D and analyzed with statistical comparisons of 2D orientation distributions of the fibers, 2D size distributions of the voids, and 2D shape distributions of the voids.
直接墨水书写(DIW)结合了3D打印的灵活性和增加的材料应用,如热固性碳纤维复合材料,陶瓷复合材料和金属。与许多增材制造(AM)工艺一样,由于质量控制和缺乏工艺参数优化等原因,直接墨水书写的实用性仍然有限。本研究旨在介绍一种表征直接墨水书写碳纤维复合材料的方法,以促进探索工艺参数与材料结构之间的关系。本研究使用了9个直接墨水书写碳纤维复合材料的3D样品,这些样品具有不同的工艺参数——速度差、层高、台阶距离和喷嘴直径——作为数据集。数据是由空军研究实验室的自动串行切片系统LEROY收集的。将收集到的数据在DREAM.3D中进行处理,统计比较纤维的二维方向分布、空隙的二维尺寸分布和空隙的二维形状分布。
Influence of thermoplastic fibre-epoxy adhesion on the interlaminar fracture toughness of interleaved polymer composites
Zaide Saka Dinç, Yahya Öz, Prasad Potluri, William W. Sampson, Hüseyin Aksel Eren
doi:10.1016/j.compositesa.2024.108619
热塑性纤维-环氧树脂黏附对交织聚合物复合材料层间断裂韧性的影响
We present an experimental study using surface modification of polyetherimide (PEI) and polyphenylene sulfide (PPS) nonwoven fibrous veils to probe their performance as interleaves to improve the interlaminar fracture toughness (IFT) of carbon fibre-epoxy composites. Veil fibre surfaces were modified with ozone and a post-treatment with ultraviolet (UV) light (ozone + UV). From surface characterisation, mechanical testing of composites and fractography we show that for the PEI veil, these surface modifications resulted in a decreased mode I IFT attributable to decreased fibre-epoxy adhesion and hence, fibre/matrix debonding. In contrast, an increase in sulfinyl functional groups on the surface of PPS fibres after ozonation was observed alongside an increase in PPS veil-epoxy adhesion. The strong bond between fibre–matrix resisted crack propagation across veils, compelling the crack to divert through weaker carbon fibre-epoxy interfaces in adjacent layers. The mode I fracture toughness during crack propagation GIprop decreased, confirming the level of veil-epoxy adhesion to be a significant contributor to the IFT that can be associated with specific functional groups on fibre surfaces.
采用聚醚酰亚胺(PEI)和聚苯硫醚(PPS)非织造纤维纱的表面改性方法,研究了它们作为交织物提高碳纤维-环氧复合材料层间断裂韧性(IFT)的性能。面纱纤维表面用臭氧改性,后处理用紫外线(UV)光(臭氧 + UV)。从表面表征、复合材料的力学测试和断口形貌来看,我们发现对于PEI膜,这些表面改性导致I型IFT降低,这是由于纤维与环氧树脂的粘附性降低,从而导致纤维/基体脱粘。相比之下,在臭氧化后,PPS纤维表面的亚砜基官能团增加,同时PPS涂层-环氧树脂附着力增加。纤维基体之间的强结合抑制了裂纹的扩展,迫使裂纹通过相邻层中较弱的碳纤维-环氧界面转移。裂纹扩展过程中的I型断裂韧性GIprop下降,这证实了纤维表面特定官能团的粘合水平是IFT的重要影响因素。
Ultrastrong and ductile Al-Mg alloy matrix composites via composition-modulated precipitation induced by intragranular ceramic nanoparticles
Zhiqi Guo, Kang Wang, Bo Cui, Zhanqiu Tan, Lei Zhao, Genlian Fan, Zan Li, Zhiqiang Li, Di Zhang
doi:10.1016/j.compositesb.2024.112012
晶内纳米陶瓷诱导成分调制析出的超强延展性铝镁合金基复合材料
Nano-precipitation is critical in achieving high yield strength and strain hardening capacity in aluminum alloys and their composites, while Al-Mg alloys and their composites are generally believed not to be strengthened significantly by precipitations. This study reveals that a coherent composition-modulated precipitate χ deviated from the conventional precipitation sequence forms near intragranular ceramic nanoparticles (ICNPs) in Al-Mg alloy matrix composites, providing precipitation strengthening of ∼120 MPa and activating early plastic relaxation around ICNPs. Thus, an Al-5Mg alloy (wt.%) reinforced with 1.5 wt.% carbon nanotubes containing χ exhibits ultrahigh tensile yield strength of 653.2 MPa with uniform elongation of 8.9%. χ is composed of alternating domains with different content of Mg and derives from disordering decomposition of metastable partially ordered δ'', as revealed by the first-principles calculations. This study subverts the understanding on the weak precipitation strengthening in Al-Mg alloys and their composites, and enlightens exploiting superior strength and ductility via ICNPs induced exotic precipitation strengthening.
纳米析出是铝合金及其复合材料获得高屈服强度和应变硬化能力的关键,而Al-Mg合金及其复合材料一般认为沉淀不会显著增强。该研究表明,在Al-Mg合金基复合材料中,颗粒内陶瓷纳米颗粒(ICNPs)附近形成了偏离常规沉淀顺序的相干成分调制沉淀χ,提供了~ 120 MPa的沉淀强化,并激活了ICNPs周围的早期塑性松弛。因此,含χ的碳纳米管增强Al-5Mg合金(wt.%)的抗拉屈服强度达到653.2 MPa,均匀伸长率达到8.9%。χ由不同Mg含量的交替结构域组成,由亚稳部分有序δ”的无序分解得到,由第一性原理计算得出。本研究颠覆了以往对Al-Mg合金及其复合材料弱析出强化的认识,为利用ICNPs诱导的异相析出强化获得优异的强度和延展性提供了启示。
Enhancing the bonding reliability of titanium alloy / CFRTP hybrid joint by directionally inducing high-density covalent bond and secondary interaction via functional diblock copolymer
Jianhui Su, Caiwang Tan, Xinbo Wang, Yifan Liu, Xueyan Zhang, Swee Leong Sing, Bo Chen, Yunhua Deng, Xiaoguo Song
doi:10.1016/j.compositesb.2024.112017
通过功能双嵌段共聚物定向诱导高密度共价键和二次相互作用,提高钛合金/ CFRTP复合接头的连接可靠性
The hybrid joint of titanium alloy (Ti-6Al-4V) / carbon fibers reinforced thermoplastic (CFRTP) has gained high interest from the industry due to lightweight. However, the bonding reliability of fabricated joints is relatively low due to the confined mechanical interlocking and weak interfacial chemical interactions, which limits its application for engineering. Herein, the novel functional poly glycidyl methacrylate-b-poly methacryloxy propyl trimethoxyl silane (PGMA-b-PMPTS) diblock copolymers were synthesized and introduced at the contact interface of Ti-6Al-4V / carbon fibers reinforced polyether-ether-ketone joints for enhancing the bonding reliability by directional induction of chemical interactions. Fourier-transform infrared spectroscopy (FT-IR) analysis and density function theory (DFT) simulation calculation proved that both the Si-O-Ti covalent bonds and secondary interactions were successfully induced directionally at the bonding interface. The tensile-shear strength and bending strength were thus significantly improved by 341 % to 40.17 MPa and 152 % to 238.53 MPa compared with that of 9.09 MPa and 94.53 MPa in pretreated case. The bonding reliability improved gradually with the increase of molecular weight and molecular weight ratios between functional groups of PGMA-b-PMPTS diblock copolymers. The adhesion ratio of resin-carbon fibers mixture on failure surface increased to 89.6 % after the modification with synthesized PGMA-b-PMPTS diblock copolymers, which further verified the feasibility of promoting bonding strength of Ti-6Al-4V / CFRTP by inducing the high-density interfacial interactions directionally. Current work exhibits a simple yet attractive interfacial modification strategy to achieve high-reliability hybrid joints between metal and thermoplastics.
钛合金(Ti-6Al-4V) /碳纤维增强热塑性塑料(CFRTP)复合接头因其轻量化而受到业界的高度关注。然而,由于有限的机械联锁和弱的界面化学相互作用,制造接头的结合可靠性较低,限制了其在工程上的应用。本文合成了新型功能聚甲基丙烯酸甘油酯-b-聚甲基丙烯酸氧基丙基三甲氧基硅烷(PGMA-b-PMPTS)二嵌段共聚物,并将其引入Ti-6Al-4V /碳纤维增强聚醚醚酮接头的接触界面,通过化学相互作用的定向诱导来提高键合的可靠性。傅里叶变换红外光谱(FT-IR)分析和密度泛函理论(DFT)模拟计算证明,Si-O-Ti共价键和二次相互作用都在键界面处成功定向诱导。抗剪强度和抗折强度分别比预处理后的9.09 MPa和94.53 MPa提高了341%和152%,分别达到40.17 MPa和238.53 MPa。随着PGMA-b-PMPTS二嵌段共聚物分子量和官能团间分子量比的增加,键合可靠性逐渐提高。合成的PGMA-b-PMPTS双嵌段共聚物改性后,树脂-碳纤维混合物在破坏表面的粘附率提高到89.6%,进一步验证了通过定向诱导高密度界面相互作用提高Ti-6Al-4V / CFRTP结合强度的可行性。目前的工作展示了一种简单而有吸引力的界面改性策略,以实现金属和热塑性塑料之间的高可靠性混合接头。
Exploring properties and hydration mechanisms in clinker-free cement formulated from steel industry solid waste using the extreme vertices method
Jie Liu, Jihui Zhao, Jiankai Liang
doi:10.1016/j.compositesb.2024.112018
利用极值顶点法研究钢铁工业固废配制的无熟料水泥的性能和水化机理
The development of clinker-free cementitious binders (CFCB) using industrial solid waste has attracted widespread attention due to their environmental and cost benefits. This study developed a CFCB using ground blast furnace slag (GBFS), steel slag (SS), and flue gas desulfurization gypsum (FGDG) as raw materials, utilizing an extreme vertex design method. The study systematically assessed the effects of each component on the CFCB’s properties, hydration behavior, and microstructure, and based on these findings, further elucidated its hydration mechanism using thermodynamic simulations. Results indicated that FGDG played a critical role in regulating the fluidity of the fresh pastes and the compressive strength of the hardened pastes. GBFS enhanced the development of compressive strength, while the high-activity aluminates in SS enhanced the early-stage compressive strength. Thermodynamic simulations and experimental results confirmed that reactive aluminates and sulfates led to the formation of expansive hydration products AFt and AFm, with volume expansion peaking around 10 d. As the hydration reaction progressed, the number of aluminates participating in the reaction gradually increased, promoting the formation of C-A-S-H, hydrogarnet, and hydrotalcite, as well as the transformation of AFt into AFm. Comprehensive analysis suggested that within the GBFS-SS-FGDG system, the proportion of FGDG should not be less than 10%, the content of GBFS should be controlled between 50-57.5%, and the content of SS should not exceed 37.5%. This study revealed the hydration mechanisms within the GBFS-SS-FGDG system, emphasizing the critical roles of each component.
利用工业固体废弃物开发无熟料胶凝粘结剂(CFCB)因其环境效益和成本效益而受到广泛关注。本研究采用极限顶点设计方法,以高炉磨渣(GBFS)、钢渣(SS)和烟气脱硫石膏(FGDG)为原料,开发了CFCB。本研究系统评估了各组分对CFCB性能、水化行为和微观结构的影响,并在此基础上通过热力学模拟进一步阐明了CFCB的水化机理。结果表明,FGDG对新鲜膏体的流动性和硬化膏体的抗压强度起着至关重要的调节作用。GBFS增强了抗压强度的发展,而SS中的高活性铝酸盐增强了早期抗压强度。热力学模拟和实验结果证实,活性铝酸盐和硫酸盐导致膨胀水化产物AFt和AFm的形成,体积膨胀在10 d左右达到峰值。随着水化反应的进行,参与反应的铝酸盐数量逐渐增加,促进了C-A-S-H、水榴石和水滑石的形成,并促进了AFt向AFm的转化。综合分析认为,在GBFS-SS-FGDG体系内,FGDG的比例不应低于10%,GBFS的含量应控制在50-57.5%之间,SS的含量不应超过37.5%。本研究揭示了GBFS-SS-FGDG体系的水化机制,强调了各组分的关键作用。
Porous conductive composite as piezoresistive sensors for smart safety helmet
Suhyeon Kim, Yeonhee Heo, Hyein Jung, Jeongmin Yoo, Jin-Tae Kim, Yoonseok Park
doi:10.1016/j.compscitech.2024.110985
多孔导电复合材料压阻式智能安全帽传感器
Safety helmets are essential protective gear for workers in hazardous environments, capable of reducing external impact forces by 90%. Proper helmet usage in any situation is crucial for ensuring maximum protection. In dangerous scenarios, if a helmet is dislodged or misaligned due to an external impact makes secondary impacts difficult to prevent. Quick adjustment to the correct position is essential. In this context, it is important to develop a smart helmet system capable of monitoring the spatial pressure distribution at the boundary between the helmet and head. Such a system could further provide guidance to users for proper wearing, enhancing safety in the work environment. This paper introduces the micro-porous elastomeric conductive composite as a soft, ultra-sensitive pressure sensor for low pressure regime (0-200 kPa). The sensor combines with a vibrotactile actuator and microcontroller, creating a haptic interface that responds to changes in pressure. Integrating haptic interfaces into safety helmets, smart helmets yield a system capable of real-time measurement of pressure between the helmets and head and delivers the wearing conditions to users. Detailed research into the materials, mechanical engineering aspects of this device, along with pilot perception tests, establishes the technical foundation and measurement capabilities of the proposed system.
安全帽是工人在危险环境中必不可少的防护装备,能够减少90%的外部冲击力。在任何情况下正确使用头盔对于确保最大程度的保护至关重要。在危险情况下,如果头盔因外部撞击而移位或错位,则难以防止二次撞击。迅速调整到正确的位置是必要的。在这种情况下,开发一种能够监测头盔与头部之间边界空间压力分布的智能头盔系统非常重要。该系统可以进一步指导用户正确佩戴,提高工作环境的安全性。本文介绍了一种用于低压(0- 200kpa)的柔性、超灵敏的微孔弹性导电复合材料压力传感器。该传感器结合了振动触觉致动器和微控制器,创建了一个响应压力变化的触觉界面。将触觉接口集成到安全帽中,智能头盔产生了一个能够实时测量头盔和头部之间压力的系统,并向用户提供佩戴条件。对该装置的材料、机械工程方面的详细研究,以及试点感知测试,建立了拟议系统的技术基础和测量能力。