今日更新:Composite Structures 4 篇,Composites Part A: Applied Science and Manufacturing 3 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
A comprehensive review on mechanical properties and damage mechanisms of 3DWCs under various influencing factors
Yonghao Xu, Wensuo Ma, Xiaoqiang Wang, Ma Zhenyu, Huang Zhaohua, Man Ruidong
doi:10.1016/j.compstruct.2024.118523
各种影响因素下3DWCs的力学性能及损伤机理综述
Three-dimensional woven composites (3DWCs) have received widespread attention due to their advantages, such as integral near-net molding of complex components and high damage tolerance. However, 3DWCs exhibit significant variations in mechanical behavior under various influencing factors, which poses challenges in selecting appropriate application scenarios. In recent years, there has been rapid development in the performance analysis and modeling strategies for 3DWCs, leading to substantial results. This paper provides a comprehensive overview of the mechanical properties and damage mechanisms of 3DWCs under various influencing factors, aiming to facilitate the selection of 3DWCs for different engineering applications and to complement the existing database of mechanical properties.
三维机织复合材料(3DWCs)因其具有复杂部件整体近净成型和高损伤容限等优点而受到广泛关注。然而,在各种影响因素下,3DWCs的力学性能表现出明显的变化,这给选择合适的应用场景带来了挑战。近年来,针对3DWCs的性能分析和建模策略得到了快速发展,并取得了丰硕的成果。本文全面综述了各种影响因素下3DWCs的力学性能和损伤机理,旨在为不同工程应用选择3DWCs提供方便,并对现有的力学性能数据库进行补充。
Enhancing the thermal conductivity of polystyrene/polyamide 6/graphene nanoplatelets composites through elongational flow
Shuai Wen, Jianming Chen, Jingjing Zhang, Zhangyuan Peng, Tinghui Huang, Zhansong Yin, Ruijie Xu, Anfu Chen, Caihong Lei
doi:10.1016/j.compstruct.2024.118527
通过拉伸流动增强聚苯乙烯/聚酰胺6/石墨烯纳米片复合材料的导热性
Migration and distribution of thermal conduct fillers in polymer blend are key factors in the preparation of enhanced thermal conductivity composite. In this study, polystyrene(PS)/polyamides 6(PA6)/graphene nanoplatelets(GNPs) composites with enhanced thermal conductivity were prepared under elongational flow, and the migration and distribution of GNPs were investigated by molecular dynamics simulation and experiments. The results showed that when GNPs immigrate from PA6 phase to PS phase, the elongational flow caused the orientation of the PS phase and GNPs, reducing the migration rate of GNPs from the PA6 phase to the PS phase. At the same time, the stretching viscosity of the PS phase increases, which prevents GNPs entering the PS phase. As a result, GNPs remain within the PA6 phase near the interface of the two phases. The effective distribution density of GNPs increased, making it easier for them to interconnect and form thermal conduction paths, thereby improving the thermal conductivity of the composites. Particularly, the composite prepared under the elongational flow with the 50/50 vol ratio of PS/PA6, the in-plane thermal conductivity of PS/PA6/GNPs composites reached a maximum of 1.64 W/(m·K).
导热填料在聚合物共混物中的迁移和分布是制备增强导热复合材料的关键因素。本研究在拉伸流动条件下制备了具有增强导热性的聚苯乙烯(PS)/聚酰胺6(PA6)/石墨烯纳米片(GNPs)复合材料,并通过分子动力学模拟和实验研究了GNPs的迁移和分布。结果表明:当GNPs从PA6相向PS相迁移时,拉长流动引起PS相和GNPs的取向,降低了GNPs从PA6相向PS相迁移的速率;同时,PS相的拉伸粘度增大,阻止了GNPs进入PS相。因此,GNPs停留在两相界面附近的PA6相内。GNPs的有效分布密度增加,使其更容易相互连接并形成导热路径,从而提高了复合材料的导热性。特别是当PS/PA6的 体积比为50/50时,PS/PA6/GNPs复合材料的面内导热系数达到了1.64 W/(m·K)的最大值。
A preparation method for microstructure of flexible pressure sensors based on origami craft
Liangsong Huang, Yu Zhang, Peng Zhang, Zhongkai Zhao, Zhifu Chen
doi:10.1016/j.compstruct.2024.118544
基于折纸工艺的柔性压力传感器微结构制备方法
With the development of flexible pressure sensors, an increasing number of microstructures and their preparation methods have been developed. However, how to reduce the cost and complexity of microstructure preparation while ensuring sensors’ performance and microstructure diversity remains a significant challenge. This paper explores the feasibility and diversity of origami craft in the microstructure preparation. Based on origami craft, various different microstructures, such as linear, cross, wrinkle and wave, could be prepared using low-cost silicone paper as mold material and simple steps. Due to the diversity of origami craft in microstructure preparation, our sensors with different microstructures also have their own advantage interval of pressure detection (0–4.4 kPa: the sensitivities of piezoresistive sensors with linear and cross microstructures are So = -0.31 kPa−1, St = -0.34 kPa−1; 4.4–13.3 kPa: the sensitivity of the piezoresistive sensor with wave microstructure is Swa = -0.028 kPa−1), some of the sensors have rapid response times, excellent response characteristics, repeatability, and hysteresis. Sensors designed for low-pressure applications can detect pressures as low as 22 Pa. Additionally, it was observed that they possess significant potential in human motion environments, office environments, and equipment testing environments. This indicates that origami craft offers excellent diversity and feasibility in the preparation of sensor microstructures.
随着柔性压力传感器的发展,人们开发了越来越多的微结构及其制备方法。然而,如何降低微结构制备的成本和复杂性,同时确保传感器的性能和微结构的多样性,仍然是一个重大挑战。本文探讨了折纸工艺在微结构制备中的可行性和多样性。在折纸工艺的基础上,使用低成本的硅胶纸作为模具材料和简单的步骤,可以制备出各种不同的微结构,如线形、十字形、皱纹形和波浪形。由于折纸工艺在微结构制备方面的多样性,我们采用不同微结构的传感器在压力检测方面也有各自的优势区间(0-4.4 kPa:采用线性和交叉微结构的压阻传感器的灵敏度分别为 So = -0. 31 kPa-1,St = -0.34 kPa-1;4.4-13.3 kPa:具有波状微结构的压阻传感器的灵敏度为 Swa = -0.028 kPa-1),部分传感器具有快速响应时间、优异的响应特性、重复性和滞后性。此外,据观察,这些传感器在人体运动环境、办公环境和设备测试环境中具有巨大的潜力。这表明,折纸工艺在制备传感器微结构方面具有出色的多样性和可行性。
Bond strength prediction of externally bonded reinforcement on groove method (EBROG) using MARS-POA
Pouyan Fakharian, Younes Nouri, Ali Reza Ghanizadeh, Farzad Safi Jahanshahi, Hosein Naderpour, Ali Kheyroddin
doi:10.1016/j.compstruct.2024.118532
基于MARS-POA的凹槽法(EBROG)外粘接钢筋粘结强度预测
The Externally Bonded Reinforcement on Grooves (EBROG) method represents an advancement in externally bonded reinforcement (EBR) techniques, specifically addressing the challenge of premature debonding often encountered in conventional Fiber Reinforced Polymer (FRP) applications directly bonded to concrete. This article introduces a novel and straightforward mathematical equation for predicting bond strength in the EBROG method using soft computing techniques for the first time. The study delves into the combined potential of the Multivariate Adaptive Regression Spline (MARS) model and the Pelican Optimization Algorithm (POA) for bond strength prediction in this method. The input parameters include FRP width, FRP thickness, elasticity modulus of FRP, concrete strength, groove length, groove width, and groove depth, while the output is EBROG bond strength. The study demonstrates exceptional accuracy with R2 values of 0.9629 for training and 0.9598 for testing, highlighting the model’s precision. The proposed bond strength prediction equation for the EBROG method undergoes validation against existing models, encompassing thirteen equations for EBR and a recent one specific to EBROG. Statistical metrics confirm the accuracy and reliability of the proposed equation. Notably, FRP stiffness emerges as the parameter with the highest relative importance, while groove width exhibits the lowest impact on bond strength.
沟槽外粘接加固(EBROG)方法代表了外粘接加固(EBR)技术的进步,特别是解决了直接粘合到混凝土上的传统纤维增强聚合物(FRP)应用中经常遇到的过早脱粘的挑战。本文首次采用软计算技术,在EBROG法中提出了一种新颖、直观的预测粘结强度的数学方程。研究了多变量自适应回归样条(MARS)模型和鹈鹕优化算法(POA)在该方法中结合预测粘结强度的潜力。输入参数为FRP宽度、FRP厚度、FRP弹性模量、混凝土强度、沟槽长度、沟槽宽度、沟槽深度,输出参数为EBROG粘结强度。研究表明,该模型的准确率非常高,训练的R2值为0.9629,测试的R2值为0.9598,突出了模型的精度。提出的EBROG方法的粘结强度预测方程经过对现有模型的验证,包括13个EBR方程和最近一个特定于EBROG的方程。统计指标证实了所提方程的准确性和可靠性。值得注意的是,FRP刚度是相对重要性最高的参数,而槽宽对粘结强度的影响最小。
Effect of stacking pattern of multilayered polyetheretherketone/boron nitride composites on the mechanical and thermal properties: Experiments and molecular dynamics simulations
Yuna Oh, Kwak Jin Bae, Yonjig Kim, Jaesang Yu
doi:10.1016/j.compositesa.2024.108441
多层聚醚酮/氮化硼复合材料堆积方式对力学和热性能的影响:实验和分子动力学模拟
The effect of stacking patterns in multilayered polyetheretherketone (PEEK)/boron nitride (BN) composites was investigated to improve the thermal conductivity and mechanical properties. The thick PEEK and BN layers in the multilayered composite were the best multilayer structure, resulting in high mechanical properties and in-plane thermal conductivity due to the many strong electrostatic interaction sites between boron nitride nanosheets (BNNSs). Molecular dynamics simulations were used to clarify the enhanced mechanism of multilayered structure on thermal conductivity. The multilayered structure with combinations of PEEKs and thick BN layers composed of large BNNSs led to the optimization of heat transfer due to the effective phonon transfer path. The best multilayered composite had the highest in-plane thermal conductivity, which was 471% higher than that of a PEEK. This study provides information about the filler size and stacking patterns for more effective multilayer structures with polymer and filler layers to achieve high performance on mechanical and thermal properties.
研究了多层聚醚酮(PEEK)/氮化硼(BN)复合材料中堆叠方式对其导热性能和力学性能的影响。由于氮化硼纳米片(BNNSs)之间存在许多强静电相互作用位点,因此多层复合材料具有较高的力学性能和面内导热系数。利用分子动力学模拟阐明了多层结构对导热性能的增强机理。由于有效的声子传递路径,peek和由大BNNSs组成的厚BN层组合的多层结构导致了传热的优化。最佳的多层复合材料具有最高的面内导热系数,比PEEK高出471%。本研究为更有效的聚合物和填料层多层结构提供了填料尺寸和堆叠模式的信息,以实现高性能的机械和热性能。
Synergy performance of hybrid fiber-reinforced ultra-high-performance cementitious composites with low fiber contents
Ngoc Thanh TRAN, Duy Hung NGUYEN, Tuan Kiet TRAN, Dong Joo KIM, Duy-Liem NGUYEN
doi:10.1016/j.compositesa.2024.108423
低纤维含量混杂纤维增强超高性能胶凝复合材料的协同性能研究
This study aims to assess the synergistic tensile performance resulting from the hybridization of long and short fibers. Three types of long steel,fibers, i.e., twisted, hooked, and smooth fibers, along with two types of short fibers, i.e., smooth and polyamide fibers, were incorporated into ultra-high-performance concrete (UHPC) at a total volume content of 1.5%. To predict the tensile resistance of the hybridizations, various machine learning models, including artificial neural network (ANN), decision tree (DT), random forest (RF), and support vector machine (SVM), were applied by utilizing a significant number of collected experimental results. Experimental findings demonstrated that the hybridization of long and short fibers effectively enhanced tensile resistance compared to mono fibers. These hybridizations exhibited negative synergy factors in post-cracking strength but positive synergy factors in both strain capacity and specific work to fracture. Predictions using machine learning models revealed that the RF model exhibited outstanding performance in predicting the tensile resistance of the hybridizations. Furthermore, the compressive strength of the matrix was found to be the most important factor affecting post-cracking strength, whereas fiber length had the most substantial impact on the strain capacity.
本研究旨在评估长、短纤维杂交后的协同拉伸性能。将三种长纤维(捻、钩、光面纤维)和两种短纤维(光面纤维和聚酰胺纤维)以1.5%的体积含量掺入高性能混凝土(UHPC)中。为了预测杂交的抗拉性,利用收集到的大量实验结果,应用了各种机器学习模型,包括人工神经网络(ANN)、决策树(DT)、随机森林(RF)和支持向量机(SVM)。实验结果表明,与单纤维相比,长纤维和短纤维的杂交有效地提高了抗拉性能。这些杂化在开裂后强度方面表现为负协同因子,而在应变能力和断裂比功方面表现为正协同因子。使用机器学习模型的预测表明,RF模型在预测杂交的拉伸阻力方面表现出出色的性能。此外,发现基体的抗压强度是影响开裂后强度的最重要因素,而纤维长度对应变能力的影响最大。
Development of sandwich test coupons with continuous protective layers for accurate determination of the tensile failure strain of unidirectional carbon fibre reinforced composites
Gergely Czél
doi:10.1016/j.compositesa.2024.108440
为准确测定单向碳纤维增强复合材料拉伸破坏应变而研制的连续保护层夹芯试验片
Recently introduced unidirectional (UD) carbon fibre reinforced epoxy (CF/EP) tensile test coupons with continuous protective layers were developed further by comparing three coupon designs with different layer integration techniques. Consistent experimental data was generated with high sample number and low scatter. Thermal residual strains were considered in case of two coupon designs where the layers were integrated at elevated temperature. A curve-fitting-based strength evaluation method is proposed for the sandwich coupons since this parameter cannot be evaluated directly. The sandwich type coupons yielded statistically significant increase in their average failure strain compared to that of the baseline tabbed coupons. In contrast, the three sandwich coupon types did not show significant differences. Therefore, the sandwich coupon type made by bonding cured UD composite layers together at room temperature is proposed for further application as they allow for full delamination at CF/EP layer fracture and do not require thermal strain correction during the evaluation.
通过对三种不同保护层集成技术的单向碳纤维增强环氧树脂(CF/EP)拉伸试验片的比较,进一步开发了具有连续保护层的单向碳纤维增强环氧树脂(CF/EP)拉伸试验片。实验数据一致,样本数高,散点低。热残余应变的情况下,考虑两个联片设计,其中层在高温下集成。针对夹芯板的强度参数无法直接评估的问题,提出了一种基于曲线拟合的夹芯板强度评估方法。与基线标签式夹芯板相比,夹芯板的平均破坏应变在统计上显著增加。相比之下,三种三明治优惠券类型没有显着差异。因此,在室温下将固化的UD复合材料层粘合在一起制成的三明治夹片类型可以在CF/EP层断裂时完全分层,并且在评估过程中不需要热应变校正,因此可以进一步应用。
Influence of reinforcement phase content on mechanical properties of hydroxyapatite/carbon fiber/polyether-ether-ketone composites 3D printed by screw extrusion
Beining Zhang, Siwei Lu, Jingyi Niu, Chuncheng Yang, Changning Sun, Dichen Li
doi:10.1016/j.compscitech.2024.110843
增强相含量对羟基磷灰石/碳纤维/聚醚醚酮复合材料3D打印力学性能的影响
Hydroxyapatite/polyether-ether-ketone (HA/PEEK) composites are promising prosthesis materials due to their biological activity, but they often have mechanical properties that fall short of clinical requirements, typically with HA content below 40 wt%. This study utilized a customized screw extrusion-based 3D printhead, incorporating carbon fiber (CF) to produce HA/CF/PEEK composites with enhanced mechanical properties and HA content up to 60 wt%. The investigation focused on the effects of HA and CF content on the crystallization process and mechanical properties. Results showed that HA and CF affect crystallization differently due to varying densities; a phase volume ratio above 20% inhibits crystallization. The elongation at break for composites with 10 wt% HA was 27.9%, a record for 3D-printed HA/PEEK composites. The tensile strength for composites with 10 wt% HA and 40 wt% CF reached 115.7 MPa, the highest among the tested three-phase composites. Data fitting indicated that the effects of HA and CF on strength are independent. The toughness decreases exponentially with increased reinforcing phase content. This study explored a new method for preparing HA/PEEK and HA/CF/PEEK composites, expanding the performance boundaries of PEEK composites, enhancing their potential applications in bone implants.
羟基磷灰石/聚醚酮(HA/PEEK)复合材料由于其生物活性是很有前途的假体材料,但它们的机械性能往往达不到临床要求,通常HA含量低于40%。这项研究使用了定制的基于螺杆挤压的3D打印头,结合碳纤维(CF)来生产具有增强机械性能和HA含量高达60%的HA/CF/PEEK复合材料。研究了HA和CF含量对结晶过程和力学性能的影响。结果表明:HA和CF对结晶的影响因密度的不同而不同;大于20%的相体积比抑制结晶。含10 wt% HA的复合材料的断裂伸长率为27.9%,创造了3d打印HA/PEEK复合材料的记录。含10 wt% HA和40 wt% CF的复合材料抗拉强度达到115.7 MPa,在所测试的三相复合材料中最高。数据拟合表明,HA和CF对强度的影响是独立的。随着增强相含量的增加,韧性呈指数级下降。本研究探索了一种制备HA/PEEK和HA/CF/PEEK复合材料的新方法,拓展了PEEK复合材料的性能边界,增强了其在骨植入物中的潜在应用。