【新文速递】2024年2月17日复合材料SCI期刊最新文章

   

今日更新：Composite Structures 3 篇，Composites Part A: Applied Science and Manufacturing 2 篇，Composites Science and Technology 1 篇

Composite Structures

Explosive blast loading effect on transient mechanical responses of aircraft panels with curvilinear fibers: 3D elasticity approach

Y. Heydarpour, P. Malekzadeh, Krzysztof Kamil Żur

doi:10.1016/j.compstruct.2024.117967

爆炸加载对带有曲线纤维的飞机面板瞬态机械响应的影响：三维弹性方法

In the present paper, for the first time, the dynamic loading effect on transient bending and stress distributions of aircraft nanocomposite sandwich panels including curvilinear fibers are presented and explained. Face sheets of the panel contain curvilinear fibers with an orientation angle varies linearly with respect to the horizontal coordinate. The core layer is made of polymer matrix reinforced by graphene platelets (GPLs) with uniform and random orientation distribution. 3-D elasticity theory is used to formulate the transient problem of the panel. The model of the panel is so general to include different time-dependent loads, especially explosive ones. A three-dimensional layerwise-differential quadrature method (LW-DQM) together with a non-uniform rational B-spline-based multi-step time integration scheme is employed to investigate the transient responses of the sandwich panel with variable stiffness composite laminated face sheets (VSCL-FS) and graphene platelets reinforced porous core (GPLR-PC) under dynamic loading. The convergence behavior of the method is examined numerically and to assure its accuracy, the results in the limit cases are compared with those available in the literature. Finally, through the parametric studies, the effects of core porosity distribution and amounts, GPLs weight fraction and boundary conditions on the transient responses of the sandwich panel with VSCL-FS and GPLR-PC subjected to explosive blast loading are investigated. The results show that the addition of GPLs to the core layer decreases the transverse displacement but increases the peak values of the stress components. Also, the core porosity increases the transverse displacement and the stress components. However, it has not significant effect on the period of oscillation of the field variables under explosive blast loading. On the other hand, the curvature of the fibers does not considerable effect on the plate response and on the period of oscillation of the field variables under explosive blast loading.

本文首次提出并解释了动态加载对包含曲线纤维的飞机纳米复合材料夹层板瞬态弯曲和应力分布的影响。夹层板的面层包含取向角相对于水平坐标线性变化的曲线纤维。芯层由聚合物基体制成，并由具有均匀和随机取向分布的石墨烯小板（GPLs）增强。采用三维弹性理论来计算面板的瞬态问题。该面板模型具有很强的通用性，可以包含不同的随时间变化的载荷，尤其是爆炸载荷。采用三维层微分正交法（LW-DQM）和基于非均匀有理 B 样条的多步时间积分方案来研究具有可变刚度复合层压面板（VSCL-FS）和石墨烯微板增强多孔芯材（GPLR-PC）的夹芯板在动态载荷下的瞬态响应。对该方法的收敛行为进行了数值检验，并将极限情况下的结果与文献中的结果进行了比较，以确保其准确性。最后，通过参数研究，探讨了夹芯孔隙率分布和数量、GPL 重量分数和边界条件对采用 VSCL-FS 和 GPLR-PC 的夹芯板在爆炸荷载作用下的瞬态响应的影响。结果表明，在芯层中添加 GPLs 会减小横向位移，但会增加应力分量的峰值。此外，芯层孔隙率会增加横向位移和应力分量。然而，它对爆炸荷载下场变量的振荡周期影响不大。另一方面，纤维的曲率对板材响应和爆炸荷载下的场变量振荡周期没有显著影响。

Nonlinear in-plane buckling of small-curved and large-curved FG porous microbeams via strain gradient-based isogeometric collocation formulations

Saeid Sahmani, Babak Safaei, Timon Rabczuk

doi:10.1016/j.compstruct.2024.117969

通过基于应变梯度的等几何配位公式计算小曲面和大曲面 FG 多孔微梁的非线性面内屈曲

In the current investigation, for the first time, the changes in the limit loads and equilibrium branches associated with the nonlinear in-plane stability characteristics of curved microbeams are explored in the presence of different microstructural gradient tensors. In this regard, multiple microsize-dependent equilibria are analyzed relevant to thermomechanical loaded small-curved, medium-curved, and large-curved microbeams made of functionally graded porous (FGP) metal reinforced with nanofillers possessing clamped end supports. To this purpose, based upon the strain gradient elasticity within the framework of the third-order shear flexible curved beam model, the isogeometric collocation formulations incorporating Greville abscissae are constructed resulting in higher-continuity characters as well as remarkable accuracy for higher-order approximations. It is deduced that for the small-curved FGP reinforced microbeam, no limit load can be found due to the absence of the buckling phenomenon, but after rising the temperature by an enough amount, the initial instability mode appears. However, for the medium-curved FGP reinforced microbeam, the limit instability mode of buckling occurs which results in the normalized upper limit load equal to 0.7161 based on the classical theory and 0.7606 based on the strain gradient elasticity ( 6.21 % enhancement). Also, it results in the normalized lower limit load equal to 0.3060 based on the classical theory and 0.3521 based on the strain gradient elasticity ( 15.07 % enhancement). On the other hand, for the large-curved FGP reinforced microbeam, the bifurcation mode of buckling occurs which results in the normalized upper limit load equal to 1.0494 based on the classical theory and 1.1358 based on the strain gradient elasticity ( 8.23 % enhancement). Also, it results in the normalized lower limit load equal to 0.2225 based on the classical theory and 0.2513 based on the strain gradient elasticity ( 12.94 % enhancement).

在当前的研究中，首次探讨了在不同微结构梯度张量存在的情况下，与曲面微梁非线性面内稳定性特征相关的极限载荷和平衡分支的变化。在这方面，分析了与热机械加载的小弯曲、中弯曲和大弯曲微梁相关的多种微尺寸相关平衡，这些微梁由功能分级多孔（FGP）金属和纳米填料增强而成，具有夹持端支撑。为此，基于三阶剪切柔性曲线梁模型框架内的应变梯度弹性，构建了包含格雷维尔缺省的等几何配位公式，从而获得了更高的连续性特征以及高阶近似的显著精度。结果表明，对于小曲线 FGP 加固微梁，由于不存在屈曲现象，因此找不到极限载荷，但当温度升高足够高时，会出现初始不稳定模式。然而，对于中弧度 FGP 加固微梁，出现了屈曲的极限不稳定模式，根据经典理论，其归一化上限荷载等于 0.7161，而根据应变梯度弹性（增强 6.21%）理论，其归一化上限荷载等于 0.7606。此外，根据经典理论，归一化下限荷载等于 0.3060，而根据应变梯度弹性理论，归一化下限荷载等于 0.3521（提高了 15.07%）。另一方面，对于大弧度 FGP 加固微梁，出现了分叉屈曲模式，根据经典理论，归一化上限荷载等于 1.0494，而根据应变梯度弹性，归一化上限荷载等于 1.1358（增强了 8.23%）。此外，根据经典理论，归一化下限荷载等于 0.2225，而根据应变梯度弹性理论，归一化下限荷载等于 0.2513（增加了 12.94%）。

Nonconventional tow-steered pressure vessels for hydrogen storage

Shahrzad Daghighi, Paul M. Weaver

doi:10.1016/j.compstruct.2024.117970

用于储氢的非常规拖曳式压力容器

Hydrogen has high gravimetric energy density with accompanying low carbon footprint with potential to replace fossil fuels. Hydrogen at ambient temperature is in the gaseous state and should be stored in pressure vessels that can withstand pressures as large as 70 MPa , making their design challenging. Developments in manufacturing techniques for composite structures enable varying the fibre tow trajectory throughout the structure to improve the structural performance. These structures are known as variable stiffness composite structures. This technique has recently been used to develop a design method for suppressing inefficient bending in non-spherical pressure vessels. This study employs the bend-free design method for gaseous hydrogen pressure vessels and investigates the potential advantages of this nonconventional design compared to conventional designs by assessing their Hydrogen Weight Efficiency (HWE). Results show that the HWE of the bend-free variable stiffness pressure vessel is 18.6% larger than the HWE of the best conventional design studied.

氢气的重力能量密度高，碳足迹小，具有替代化石燃料的潜力。氢气在环境温度下呈气态，应储存在能承受 70 兆帕压力的压力容器中，因此其设计具有挑战性。随着复合材料结构制造技术的发展，可以改变整个结构的纤维束轨迹，从而提高结构性能。这些结构被称为可变刚度复合结构。这种技术最近被用于开发一种抑制非球形压力容器低效弯曲的设计方法。本研究将无弯曲设计方法用于气态氢压力容器，并通过评估氢重量效率（HWE），研究这种非常规设计与传统设计相比的潜在优势。结果表明，无弯曲变刚度压力容器的氢重效率比所研究的最佳传统设计的氢重效率高 18.6%。

Composites Part A: Applied Science and Manufacturing

Graphene-based high-performance pseudo-ductile glass-carbon/epoxy composites

Mohammad Hamidul Islam, Shaila Afroj, Nazmul Karim

doi:10.1016/j.compositesa.2024.108086

石墨烯基高性能伪电导玻璃-碳-环氧复合材料

High-performance fibre-reinforced polymer (FRP) composites offer outstanding specific strength and stiffness. However, their inherent brittleness can result in sudden and catastrophic failure without adequate warning, making them unsuitable for many applications. To overcome this limitation, we developed graphene-based glass-carbon FRP hybrid composites with excellent pseudo-ductile properties. Our method involves coating glass and carbon fibre fabrics with graphene-based materials using a scalable pad-dry-cure technique, followed by epoxy matrix reinforcement via vacuum-assisted resin infusion (VARI). Tensile and flexural tests reveal remarkable pseudo-ductile behaviour, with 1 wt.% GNP-coated composites show approximately ∼17.05% higher Young's modulus, ∼18.52% higher ultimate failure stress, and ∼31.73% higher strain% compared to glass-carbon/epoxy hybrids. By enabling the manufacture of high-performance pseudo-ductile composites at scale using a cost-effective manufacturing method, these composites hold significant potential for next-generation applications.

高性能纤维增强聚合物（FRP）复合材料具有出色的特定强度和刚度。然而，其固有的脆性会导致在没有足够警告的情况下突然发生灾难性的破坏，因此不适合许多应用。为了克服这一局限性，我们开发了石墨烯基玻璃-碳 FRP 混合复合材料，它具有优异的假韧性。我们的方法包括使用可扩展的垫干固化技术在玻璃纤维和碳纤维织物上涂覆石墨烯基材料，然后通过真空辅助树脂灌注（VARI）进行环氧基体加固。拉伸和弯曲测试表明，与玻璃-碳/环氧混合材料相比，涂有 1 wt.% 石墨烯的复合材料具有显著的假韧性，杨氏模量提高了约 17.05%，极限破坏应力提高了约 18.52%，应变率提高了约 31.73%。通过使用具有成本效益的制造方法大规模制造高性能伪电导复合材料，这些复合材料在下一代应用中具有巨大潜力。

Mode II fatigue characteristics of a composite bonded joint with microstructured adhesive bondline through tailored sacrificial cracks

A. Alshedayfat, A. Wagih, A. Yudhanto, H. Mahmoud, G. Lubineau

doi:10.1016/j.compositesa.2024.108090

 

带有微结构粘合剂粘合线的复合材料粘接接头通过定制牺牲裂缝的模式 II 疲劳特性

Previous studies have developed several techniques to enhance the mode II static fracture toughness of adhesive-bonded joints for structural applications. However, in real-world applications, joints are subjected to fatigue loading more frequently than static loading. In a previous study, we demonstrated static mode II toughness improvement of a modified adhesive joint with a microstructured bondline using tailored sacrificial cracks. In this study, we analyzed the mode II fatigue toughness of this joint by employing the end notch flexural test to characterize the mode II fatigue toughness of the modified bonded joints at different loads, i.e., 50%, 60%, and 70% of the maximum static load. The results demonstrated initiation fracture toughness improvement for the joints tested at 70% of maximum static load, and a one-order of magnitude lower crack growth rate than the conventional joint (interfacial crack propagation). The initiation fracture toughness improvement was caused by the presence of the first sacrificial crack, which facilitated the stress redistribution ahead of the crack tip and formed an elongated strain-affected zone. This reduces the stress intensity at the crack tip and, as a result, delays the initiation of the crack. We found that the crack growth rate improvement was associated with the formation of two adhesive ligaments at the sacrificial crack ends, which dissipated large energy due to plastic deformation and ligament breakage.

以往的研究已开发出多种技术，用于提高结构应用中粘合剂粘接接头的模式 II 静态断裂韧性。然而，在实际应用中，接头承受疲劳载荷的频率要高于静态载荷。在之前的研究中，我们利用定制的牺牲裂缝证明了具有微结构粘结线的改性粘接接头的静态模式 II 韧性的改善。在本研究中，我们采用端部缺口挠曲试验分析了该接头的模式 II 疲劳韧性，以确定改性粘接接头在不同载荷（即最大静载荷的 50%、60% 和 70%）下的模式 II 疲劳韧性。结果表明，在最大静载荷的 70% 下测试的接头的起始断裂韧性有所提高，裂纹增长速度比传统接头（界面裂纹扩展）低一个数量级。起始断裂韧性的提高是由于第一条牺牲裂纹的存在，它促进了裂纹尖端前的应力再分布，并形成了一个拉长的应变影响区。这降低了裂纹尖端的应力强度，从而推迟了裂纹的产生。我们发现，裂纹生长速度的提高与牺牲裂纹端部形成的两条粘合韧带有关，这两条韧带因塑性变形和韧带断裂而耗散了大量能量。

Composites Science and Technology

Augmentation of scarce data—A new approach for deep-learning modeling of composites

Hon Lam Cheung, Petter Uvdal, Mohsen Mirkhalaf

doi:10.1016/j.compscitech.2024.110491

 

扩充稀缺数据--复合材料深度学习建模的新方法

High-fidelity full-field micro-mechanical modeling of the non-linear path-dependent materials demands a substantial computational effort. Recent trends in the field incorporates data-driven Artificial Neural Networks (ANNs) as surrogate models. However, ANNs are inherently data-hungry, functioning as a bottleneck for the development of high-fidelity data-driven models. This study introduces a novel approach for data augmentation, expanding an original dataset without additional computational simulations. A Recurrent Neural Network (RNN) was trained and validated on high-fidelity micro-mechanical simulations of elasto-plastic short fiber reinforced composites. The obtained results showed a considerable improvement of the network predictions trained on expanded datasets using the proposed data augmentation approach. The proposed method for augmentation of scarce data may be used not only for other kind of composites, but also for other materials and at different length scales, and hence, opening avenues for innovative data-driven models in materials science and computational mechanics.

非线性路径依赖材料的高保真全场微机械建模需要大量的计算工作。该领域的最新趋势是采用数据驱动的人工神经网络（ANN）作为替代模型。然而，人工神经网络本身对数据要求较高，成为开发高保真数据驱动模型的瓶颈。本研究介绍了一种新颖的数据增强方法，无需额外的计算模拟即可扩展原始数据集。在弹塑性短纤维增强复合材料的高保真微机械模拟中，对循环神经网络（RNN）进行了训练和验证。结果表明，使用所提出的数据增强方法，在扩展数据集上训练的网络预测结果有了显著改善。所提出的稀缺数据扩增方法不仅可用于其他类型的复合材料，还可用于其他材料和不同长度尺度的复合材料，从而为材料科学和计算力学领域的创新数据驱动模型开辟了道路。