今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Science and Technology 3 篇
The influence of stochastic interface defects on the effective thermal conductivity of fiber-reinforced composites
Yiwei Wang, Junjie Ye, Lu Liu, Ziwei Li, Yang Shi, Juan Ma, Jianqiao Ye
doi:10.1016/j.compstruct.2024.118501
随机界面缺陷对纤维增强复合材料有效导热系数的影响
In this paper, a novel microscopic modeling strategy is proposed to investigate the effective thermal conductivity of composites with consideration of stochastic interface defects. To this end, the subdomain boundary element method combined with asymptotic homogenization is proposed to effectively solve the thermal conduction problem. In order to accurately capture the heat flux on the boundary and the internal region in the representative volume element (RVE), a parameterized sub-cell is constructed to discretize the RVE. On this basis, the influence of stochastic interface defects on the thermal conductivity of composites is investigated by utilizing the Monte Carlo method. Specifically, the effect of the location, length, thickness, and area of the interface defects on the thermal conductivity is investigated. A proportional decrease in the transverse thermal conductivity coefficient is found for interface defect areas ranging from 1% to 10%.
本文提出了一种考虑随机界面缺陷的复合材料有效导热系数的微观模拟方法。为此,提出了结合渐近均匀化的子域边界元方法,有效地解决了热传导问题。为了准确地捕捉代表性体积元边界和内部区域的热通量,构造了参数化子单元对代表性体积元进行离散化。在此基础上,利用蒙特卡罗方法研究了随机界面缺陷对复合材料导热性能的影响。具体而言,研究了界面缺陷的位置、长度、厚度和面积对导热系数的影响。在界面缺陷区域,横向导热系数成比例降低1% ~ 10%。
Cryogenic damage behavior of carbon fiber reinforced polymer composite laminates via fiber-optic acoustic emission
Yi-fan Su, Tong-yu Zhang, Hui Sun, Lian-hua Ma, Wei Zhou
doi:10.1016/j.compositesa.2024.108435
基于光纤声发射的碳纤维增强聚合物复合材料层合板的低温损伤行为
Cryogenic temperatures cause significant changes in the mechanical response and microscopic failure mechanisms of carbon fiber reinforced polymer (CFRP) composites. However, the mechanisms by which cryogenic temperatures affect composites are not yet fully understood due to a lack of adequate in-situ characterization techniques. Herein, the cryogenic damage evolution process of CFRP composites was investigated by constructed fiber-optic acoustic emission (AE) detection system. Tensile damage behavior of woven CFRP composites at 300 K, 153 K and 77 K was evaluated by AE characteristic response and cluster analysis combined with scanning electron microscopy. According to the results, increased damage activity within the composites at cryogenic condition promoted the release of mechanical energy, as well as an increase in the contribution of fiber damage to overall damage, which are the dominant micro-strengthening mechanisms of composite laminates under cryogenic conditions. This study provides a novel explanation for understanding the cryogenic damage behavior of composites.
低温会导致碳纤维增强聚合物(CFRP)复合材料的力学响应和微观破坏机制发生显著变化。然而,由于缺乏足够的原位表征技术,低温影响复合材料的机制尚未完全了解。利用构建的光纤声发射(AE)检测系统对CFRP复合材料的低温损伤演化过程进行了研究。采用声发射特征响应和聚类分析相结合的扫描电镜技术,对织物CFRP复合材料在300 K、153 K和77 K下的拉伸损伤行为进行了评价。结果表明,低温条件下复合材料内部损伤活度的增加促进了机械能的释放,纤维损伤对整体损伤的贡献增加,这是低温条件下复合材料层合板微观强化的主要机制。该研究为理解复合材料的低温损伤行为提供了一种新的解释。
A parametric modeling method for 3D woven composites considering realistic meso-structural characteristics
Binbin Zhang, Jingran Ge, Bingyao Li, Zengfei Liu, Shuo Liu, Jun Liang
doi:10.1016/j.compscitech.2024.110828
考虑真实细观结构特征的三维机织复合材料参数化建模方法
The precision of mesoscale simulation for three-dimensional woven composites (3DWCs) is intricately linked to the fidelity of the geometric representation. This paper aims to present a novel parametric modeling approach for generating representative volume element (RVE) of the 3DWCs while considering its realistic meso-structural characteristics. The real architecture of 3DWCs is defined to consider the squeezed surface warp tow. Tow geometry is specified, accounting for torsion of tow cross-section and crimp of weft tow path. The RVEs of the composites are geometrically assembled via a specific translational symmetry. The tensile response of the composites with the novel geometry is scrutinized utilizing a progressive damage model, compared with that of the ideal geometry. Additionally, the impact of weft tow size on the tensile response of the composites is explored.
三维编织复合材料(3DWCs)的中尺度模拟精度与几何表征的保真度密切相关。本文旨在提出一种新的参数化建模方法,在考虑三维多轴混凝土实际细观结构特征的情况下,生成三维多轴混凝土的代表性体积元。定义了考虑挤压表面翘曲束的三维网格结构。指定拖曳几何形状,考虑拖曳截面的扭转和纬纱拖曳路径的卷曲。复合材料的RVEs通过特定的平移对称进行几何组装。与理想几何形状的复合材料的拉伸响应相比,利用渐进损伤模型仔细检查了新几何形状的复合材料的拉伸响应。此外,还探讨了纬束尺寸对复合材料拉伸响应的影响。
CFRP Surface Ply-Centric Electrified Spatiotemporal Self-Heating for Anti-icing/De-icing
Yu Tian, Shuran Li, Mengze Li, Weidong Zhu, Keping Yan, Yinglin Ke
doi:10.1016/j.compscitech.2024.110831
CFRP表面胶合中心电气化时空自加热防冰/除冰
With the widespread application of carbon fiber reinforced polymer (CFRP) in engineering, the characteristics of uniformly carbon fiber (CF) orientation within a single-ply and laminated structure have inspired us to develop high-efficiency, low-consumption, manufacture-friendly, and non-destructive anti-icing/de-icing methods. Here, we propose a CFRP surface ply-centric electrified spatiotemporal self-heating (STSH) approach, which utilizes CFs in the surface ply as natural heating elements to achieve in-situ adaptable electrothermal anti-icing/de-icing. By adjusting the current waveform, the temporal heating profile can flexibly switch between a consistently stable temperature and periodically high peak temperatures, meeting the different heating characteristics required for anti-icing and de-icing, respectively. Simultaneously, the entangled CFs branch current, generating a spatial temperature gradient that enhances the design flexibility of temperature distribution. This enables energy concentration in icing-prone areas while maintaining a baseline temperature in less susceptible areas, thus reducing energy waste by up to 20%. Overall, this STSH approach is simple, efficient, and holds significant application potential, offering an innovative and feasible solution to long-standing challenges associated with anti-icing/de-icing.
随着碳纤维增强聚合物(CFRP)在工程中的广泛应用,单层和层压结构中碳纤维取向均匀的特点激发了我们开发高效、低消耗、制造友好、非破坏性的防冰/除冰方法。在此,我们提出了一种以CFRP面层为中心的电气化时空自热(STSH)方法,该方法利用面层中的CFRP作为自然加热元件来实现原位自适应电热防冰/除冰。通过调节电流波形,时间加热剖面可以在持续稳定的温度和周期性的高峰温度之间灵活切换,分别满足防冰和除冰所需的不同加热特性。同时,缠绕的CFs支路电流,产生空间温度梯度,提高了温度分布的设计灵活性。这使得在容易结冰的地区集中能源,同时在不容易结冰的地区保持基线温度,从而减少高达20%的能源浪费。总的来说,这种STSH方法简单、高效,具有巨大的应用潜力,为长期以来与防冰/除冰相关的挑战提供了创新和可行的解决方案。