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
Composite Structures
A multi-scale uncertainty analysis method based on the Hermite-Chebyshev polynomials for dynamic responses of FRP composite structures with hybrid uncertainties
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.
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.
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.
Composites Part A: Applied Science and Manufacturing
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.
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.
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
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.
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.
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.