今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Science and Technology 3 篇
Composite Structures
Broadband and robust vibration reduction in lattice-core sandwich beam with 3D-printed QZS resonators
Lei Xiao, Xiang Sun, Li Cheng, Xiang Yu
doi:10.1016/j.compstruct.2024.118626
3d打印QZS谐振器在格芯夹层梁中的宽带和鲁棒减振
The demand for lightweight lattice-core sandwich structures that exhibit superior mechanical and dynamic properties is widespread in many devices. This paper presents a lattice-core sandwich beam (LSB) with an embedded array of quasi-zero-stiffness (QZS) resonators, referred to as Q-LSB. This research distinguishes itself from existing studies on metamaterial structures with QZS resonators by investigating the nonlinear stiffness of QZS resonators and the damping of a soft three-dimensional (3D) printing material. The objective is to achieve efficient and robust vibration reduction beyond the band gap of its linear counterpart. We investigate the beam vibration using both experimental and numerical methods. The experimental results demonstrate that the resonators can entail significant vibration reduction in a wide frequency range, covering the first three eigenmodes of the host LSB. Furthermore, the reduction effect improves as the excitation level increases within the tested excitation range, highlighting the structure’s robustness against the excitation amplitude. A numerical model based on a dynamically equivalent homogenization method and the finite element method is established and experimentally validated. Subsequently, the numerical parametric results reveal that the broadband vibration reduction is due to the damping effect, while the robust vibration reduction effect is attributed to the nonlinear stiffness of the resonators.
Fracture simulation of fiber reinforced composite panels with holes
Yang Zhang, Jialu Guo, Zhan Shu, Yaojing Guan, A.S. Ademiloye
doi:10.1016/j.compstruct.2024.118627
带孔纤维增强复合材料板断裂模拟
Fiber reinforced composite (FRC) with holes have broad applications in various fields. In this study, the influence of fiber orientation and hole distribution on the fracture behavior of FRC was investigated. A phase-field modeling was established to simulate the fracture process of the composite, and the mechanical performance of unidirectional fiber reinforced composite and woven fiber reinforced composite were analyzed, respectively. Our numerical results showed that fiber orientation and hole distribution have a significant impact on the fracture behavior of FRC. We observed that aligning the fibers parallel to the loading direction led to an increase in the maximum load bearing capacity of the composite. A more uniform hole distribution can enhance the overall mechanical performance of FRC. Furthermore, in the presence of thermal shock, crack propagation tends to grow towards the hole. These findings are of great significance for understanding the fracture behavior of FRC, and for optimizing material design and fabrication processes.
Structural response of glass fiber-polymer composite bending-active elastica beam under long-term loading conditions
Tara Habibi, Landolf Rhode-Barbarigos, Thomas Keller
doi:10.1016/j.compstruct.2024.118628
长期荷载作用下玻璃纤维-聚合物复合材料主动弯曲弹性梁的结构响应
Bending-active elastica beams represent structural members which are initially installed as straight beams and then bent into arched shapes by applying horizontal displacements to one support. Designing such members for permanent structures made of fiber-polymer composites involves complex viscoelastic responses, which have not yet been thoroughly investigated. An experimental investigation of medium-scale bending-active elastica beams, consisting of pultruded glass fiber-polymer composite profiles, was thus conducted to investigate the long-term structural behavior of such members under imposed sustained bending and axial compression. The results revealed that viscoelastic responses are based on an interaction of stress relaxation and creep with their effects increased with increasing bending degree and time of exposure to sustained strains and stresses. The imposed horizontal displacement to one of the supports to maintain the bent beam shape induced sustained bending stresses in the beam. Beneficial relaxation of these stresses occurred with relaxation predicted to reach 12 % during a targeted 50-year design service life. Furthermore, the likelihood of the curved beam exhibiting in-plane deformations under sustained stresses enabled creep to occur simultaneously, with associated in-plane creep deformations and strength reduction. While creep deformations remained insignificant, progressive creep rupture occurred at highest bending degrees, exhibiting sequential creep rupture in the outer combined mat layers, delamination, crack opening and final fiber failure. Creep rupture can be prevented by postponing crack initiation in the combined mat layer beyond the targeted design service life. This can be achieved by limiting the bending degree to 50 % of the bending degree at which short-term crack initiation occurs.
Composites Part A: Applied Science and Manufacturing
Characterization and property prediction of fibre structures within discontinuous-fibre reinforced polymer matrix composites using 3D fibre cells assisted by contrastive learning
Yuheng Zhou, Pascal Hubert
doi:10.1016/j.compositesa.2024.108506
利用对比学习辅助的三维纤维细胞对非连续纤维增强聚合物基复合材料中的纤维结构进行表征和性能预测
Fibre-cell-based fibre structure characterization approach was proposed recently to characterize the fibre distribution within discontinuous-fibre reinforced polymer matrix composites (DFR PMCs) over a 2D domain. This approach determines the distribution state of each fibre based on the relative size and topological features of its fibre cell. In this study, the fibre-cell-based approach is extended for 3D fibre domains. A convolutional neural network (CNN) encoder is trained through contrastive learning to quantitatively represent topological features of 3D fibre cells. Subsequently, the feature-property correlations are established using an artificial neural network (ANN). For practical application, the ANN is integrated with an image analysis software to provide in situ predictions of local elastic modulus of a DFR PMC based on its fibre structures observed from micro-CT images. The predictions are also compared with the experimental measurements acquired through microindentation testing, and it shows a good agreement.
Design of experiments investigation into the production of all cellulose composites using regenerated cellulosic textiles
Ashley Victoria, Peter John Hine, Keeran Ward, Michael Edward Ries
doi:10.1016/j.compositesa.2024.108510
利用再生纤维纺织品生产全纤维素复合材料的实验设计研究
All cellulose composites (ACCs) can be produced from native and man-made cellulosic fibres; use of the latter provides an additional application for waste-derived regenerated fibers. ACCs were prepared using an ionic liquid dissolution method, utilizing a regenerated cellulose (Tencel) textile, with and without an interleaf cellulosic film. A design of experiments methodology was applied to explore process-property relationships; concentration of the ionic liquid and the processing time and temperature were investigated. It was found that the film remained in-between the textile layers, rather than penetrating the fiber assembly, in contrast to our previous work on cotton-based ACCs. This is due to the structural differences between Tencel and cotton fabric. A multi-response optimization was conducted through a central composite face centered strategy, which captured the film system more strongly. Optimized processing conditions were identified, yielding a Young’s modulus and strain-to-failure of 5.3 GPa and 3.5% respectively,;alidated through in-lab samples.
Experimental and numerical validation of high strain rate impact response and progressive damage of 3D orthogonal woven composites
Xue Yang, Dian-sen Li, Xiao-long Jia, Hong-mei Zuo, Lei Jiang, Stepan V. Lomov, Frederik Desplentere
doi:10.1016/j.compscitech.2024.110896
三维正交编织复合材料高应变率冲击响应及渐进损伤的实验与数值验证
Advanced three-dimensional (3D) woven composites for aerospace and automotive applications are commonly subjected to complex dynamic environments involving vibrations and impacts, resulting in examining their impact properties is extremely important. This paper first experimentally discussed the influences of strain rates, weft yarn densities and loading directions on the impact performances and failure mechanisms of 3D orthogonal woven composites (3DOWCs). Secondly, full-scale finite element models were developed to predict the stress distribution and interfacial damage evolution process. The predictions were well in agreement with the experimental results. This research revealed that the impact characteristics exhibited strain rate sensitivity. With increasing weft yarn densities, the high strain rate impact behaviors also improved. Particularly, the warp impact strength of 3DOWCs with a weft yarn density of 2 yarn/cm (W5-2) at 812 s-1 was 17.4% and 24.0% higher than that of 3DOWCs with a weft yarn density of 1.5 yarn/cm (W5-1) at 822 s-1. Meanwhile, warp impact strength consistently exceeded to that of the weft impact strength. Additionally, strain rates, weft yarn densities, and loading directions dramatically affected the stress distribution and interfacial damage evolution process of 3DOWCs. Significant warp yarns fracture and matrix cracking were the principal failure patterns in the warp impact, whereas the damage in the weft impact was dominated by localized fracture of weft yarns and interfacial debonding.
Post Impact Flexural Behavior Investigation of Hybrid Foam-Core Sandwich Composites at Extreme Arctic Temperature
Faizan Mirza, Jason P. Mack, Arnob Banik, M.H. Khan, K.T. Tan
doi:10.1016/j.compscitech.2024.110897
极端北极温度下混杂泡沫芯夹层复合材料冲击后弯曲行为研究
This study explores the post-impact bending behavior and failure mechanisms in hybrid sandwich composites made of Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP). Flexural tests conducted at both ambient room temperature and low temperature Arctic conditions reveal a significant enhancement in flexural performance when GFRP layer is incorporated on the outer side of the hybrid composite. The investigation utilizes images from testing to elucidate damage modes, including fiber and matrix cracking in the composite facesheet, as well as core shearing and debonding in the Polyvinyl Chloride (PVC) foam core. Residual flexural properties are notably influenced by stacking sequence, facesheet compressive properties, pre-existing impact damage and temperature conditions. Analytical predictions, validated experimentally, highlight the effect of stacking sequence, low temperature, and impact energy on flexural collapse modes, with competing failure modes such as indentation and core shear. Collapse maps indicate that room temperature specimens predominantly collapse through indentation, while diverse collapse mechanisms emerge due to facesheet thickness, rigidity, and degraded tensile strength. The study aims to provide fundamental insights for future composite designs tailored for Arctic applications.
Synergistic enhancement of magic triangle properties of PC tread stocks modified by amine-capped trans-1,4-poly (butadiene-co-isoprene)
Shufang Luo, Kaixuan Dong, Shuo Wang, Aihua He
doi:10.1016/j.compscitech.2024.110899
胺包覆反式-1,4-聚丁二烯-co-异戊二烯改性PC胎面胶的魔三角性能协同增强
The development of high-performance “green tires” with synergistically improved “magic triangle” properties like lower rolling resistance, higher wet-skid resistance and higher abrasion resistance has always been a hot issue. In this work, an effective strategy for developing high-performance “green tires” with simultaneously improved “magic triangle” properties of solution-polymerized styrene-butadiene rubber (SSBR)/cis-1,4-polybutadiene rubber (BR) nanocomposites modified by amine-capped trans-1,4-poly(butadiene-co-isoprene) copolymers (F-TBIR) was proposed. A series of F-TBIR with 10-60 mol% amine-capped efficiency (CE) and 30-90×104 weight-average molecular weight (Mw) were synthesized by using heterogeneous TiCl4/MgCl2-Al(i-Bu)3 Ziegler-Natta catalyst with dicyclohexylamine (DCHA) as chain transfer agent (CTA). With the increase in CE of F-TBIR, the silica-filled SSBR/BR/F-TBIR compounds exhibited improved green strength, modulus at 100% elongation and bound rubber, and their vulcanizates showed synergistically improved “magic triangle” properties like obviously reduced rolling resistance and abrasion loss, and increased wet-skid resistance. It was found that the incorporation of 10 phr F-TBIR3 with CE of 60% and Mw of 32×104 resulted in highly expected properties of the SSBR/BR/F-TBIR3 nanocomposite. The contribution mechanism of F-TBIR3 was discussed based on the improvements of polymer network structures and filler network structures. This work is expected to provide an effective strategy to construct the desired network structures for high-performance rubber composites.