Co-Curing of CFRP-Steel Hybrid Joints Using the Vacuum Assisted Resin Infusion Process

This study focuses on the one-step co-curing process of carbon fiber reinforced plastics (CFRP) joined with a steel plate to form a hybrid structure. In this process CFRP laminate and bond to the metal are realized simultaneously by resin infusion, such that the same resin serves for both infusion and adhesion. For comparison, the commonly applied two-step process of adhesive bonding is studied. In this case, the CFRP laminate is fabricated in a first stage through resin infusion of Non Crimp Fabric (NCF) and joined to the steel plate in a further step through adhesive bonding. For this purpose, the commercially available epoxy-based Betamate 1620 is applied. CFRP laminates were fabricated using two different resin systems, namely the epoxy (EP)-based RTM6 and a newly developed fast curing polyurethane (PU) resin. Results show comparable mechanical performance of the PU and EP based CFRP laminates. The strength of the bond of the co-cured samples was in the same order as the samples adhesively bonded with the PU resin and the structural adhesive. The assembly adhesive with higher ductility showed a weaker performance compared to the other tests. It could be shown that the surface roughness had the highest impact on the joint performance under the investigated conditions.     

RFI工艺中有关树脂流动监测的研究

渗透率测定是树脂膜熔渗(RFI)工艺在复合材料设计和优化中最关键的技术.基于光导纤维视觉技术,通过纤维视觉传感器测量渗透率,能够在光强度下降的情况下探测出树脂的前进情况,这将易于我们在实际生产中在第一时间内准确地监测树脂的流动.     

复合材料RFI成形的树脂膜揭取性研究

采用树脂膜/离型纸的T型剥离实验方法来表征RFI树脂膜操作过程中的揭取特性,实验研究了几种基本RFI树脂膜的T形剥离载荷-位移关系在不同加载速度及不同实验温度下的表现形式.结果显示内聚破坏与界面破坏情况下载荷位移曲线有明显不同的形式.提高温度有利于出现内聚破坏,而提高实验速度则易于出现界面破坏.进一步从实验数据总结出树脂膜揭取的工艺范围应当在出现界面破坏的温度范围内.     

Three-Dimensional Flow Simulations for the Resin Transfer Molding Process

In resin transfer molding (RTM) a stack of fiber mats or woven rovings is laid inside the mold cavity. Then the mold is sealed and resin is injected. The computer simulation of the injection phase in resin transfer molding (RTM) can help the mold designer to position properly the injection ports and the air vents, to select an adequate injection presssure and to optimize the cycle time. The purpose of this article is to present a finite element simulation model of the filling process that can be applied to three-dimensional “thin shell” molds. An application to a subway seat is described to illustrate the various stages of the simulation     

嵌入加强筋的缝合泡沫夹芯结构复合材料VARTM工艺树脂充填模拟及验证

在缝合泡沫夹芯结构复合材料的泡沫中嵌入轻质的加强筋板,可以在不增加缝合密度并且在只增加较少质量的前提下,增强复合材料制品整体的强度和刚性。文中对真空辅助树脂传递模塑成型(VARTM)工艺树脂在嵌入加强筋的缝合泡沫夹芯结构复合材料预成型体中充填过程进行模拟和验证研究。采用一种矩形流道模型代替沿加强筋与泡沫空隙间的树脂流动,并对其等效渗透率及孔隙率进行计算;通过PAM-RTM软件模拟了嵌入加强筋板的缝合泡沫夹芯结构VARTM工艺的树脂充填过程,并建立了流动可视化实验装置与模拟对比,结果表明模拟与实验相当吻合。而模拟与实验的结果均表明加强筋的引入可以在局部加强树脂沿厚度方向的流动,但是会延缓树脂对整个预成型体的充填。     

智能材料工艺与结构中的先进传感器的发展

建立复合材料成型过程的智能化在线监控系统,有效地调整生产工艺,科学设计和优化生产工艺,可以有效地提高生产质量,降低生产成本。除生产工艺智能化外,还需建立材料结构的智能化体系,从复合材料固化成型、材料生产到材料应用整个过程均实现智能化,将开辟材料科学研究的新途径。建立智能材料工艺与结构体系需要先进的性能优良的传感器,本文以智能材料体系为背景阐述了各种传感器技术性能及发展方向。     

Temperature Dependence of Resin Flow in a Resin Film Infusion (RFI) Process by Ultrasound Imaging

Ultrasonic imaging in the C-scan mode was used in conjunction with the amplitude of the reflected signal to measure the temperature dependence of resin flow rate in single layers of woven carbon fabric. The RFI samples were vacuum-bagged and scanned in a water tank at 50°C, 60°C, 70°C, and 80°C. The measured flow rates were plotted versus inverse viscosity to determine the permeability in the thin film, non-saturated system. The permeability values determined in this work were consistent with permeability values reported in the literature. Capillary flow was not observed at the temperatures and times required for pressurized flow to occur. The flow rate at 65°C was predicted from the measured flow rates, and then measured in a 10-layer laminate. The investigation demonstrates that ultrasonic imaging in the C-scan mode in conjunction with the amplitude of the reflected signal is an effective method for measuring resin flow through fabric.     

树脂传递模塑-复合材料成型新工艺

树脂传递模塑是一种新型的树脂基复合材料成型方法 ,具有许多独特的优点 ,近年来发展迅速。本文全面综述了该方法的工艺过程及研究应用概况 ,介绍了今后进一步发展的方向。     

新型铌-硅基共晶自生复合材料的研究进展

综述了作为一种新型超高温金属结构材料的铌-硅基共晶自生复合材料的研究进展，讨论了该材料的成分设计特点，介绍了该材料密度低、承温能力高、室温断裂韧性好、高温强度高和高温持久寿命长等性能优势。     

复合材料网格结构软模成型工艺参数匹配分析

作为一种低成本的先进工艺,软模工艺因其膨胀压力的可控性受到了工程界的重视.在满足不同结构要求的前提下,工艺参数选择的合理性是降低复合材料网格结构残余应力,提高网格结构性能的关键.本文对软模工艺过程进行了数值仿真,并通过分析复合材料网格软模成型工艺中温度和压力的变化规律,旨在研究不同工艺参数对复合材料网格结构中肋骨固化压力的影响,为复合材料网格结构的低成本生产提供依据.     

A New Method to Track Resin Flow Fronts in Mold Filling Simulation of RTM Process

A new method to track resin flow fronts, referred to as the topological interpolated method (TIM), which is based onfilling states and topological relations of adjacent nodes was proposed. An experiment on the mould filling process wasconducted. It was compared with exact solutions and the experimental results, and good agreements were observed.Numerical and experimental comparisons with the conventional contour mathod were also carried out, and it showedthat TIM could enhance the local accuracy of flow front solutions with respect to the contour method when mergingflow fronts and resin approaching the mold wall were involved.     

树脂基复合材料改性技术

概述了树脂基复合材料物理及化学改性技术的作用机理,以及近年来改性技术的最新进展情况,对几种典型改性树脂基复合材料做了简要的介绍.     

树脂基复合材料固化的计算机模型EI

本文主要介绍树脂基复合材料固化计算机模型研究目的，模型特点，进展及存在问题。     

结构参数对树脂基纤维编织复合材料折叠夹芯结构力学性能的影响

折叠夹芯结构是一种新型的复合材料夹芯结构,其结构参数对力学性能有重要的影响。文中以碳纤维和Kevlar平纹编织预浸料为芯材原料,采用热压工艺,制备了复合材料折叠夹芯结构试样。通过压缩试验得到不同条件下折叠夹芯结构在静态压缩载荷作用下的力-位移变化曲线。构建了复合材料折叠夹芯结构有限元模型,对不同结构参数复合材料折叠夹芯的力学性能进行了数值模拟分析,并将模拟结果与实验结果进行对比验证了模型的可靠性。实验及数值模拟的分析结果表明,随着芯材厚度的增加,折叠夹芯层的压缩强度呈线性增加,其破坏形式由假塑性变形逐渐向脆性破坏转化;面板对夹芯层的约束作用能够极大地提高压缩模量和强度,而且上下面板对压缩性能曲线有着不同的影响;折叠夹芯单元的高度、长度、折叠夹角等参数对其力学性能具有不同程度的影响。     

粘弹性复合材料网格结构软模工艺数值仿真

复合材料网格结构软模成型共固化工艺具有低成本,高效率和高质量的特点.首先建立了网格结构软模成型共固化工艺过程有限元分析的数值仿真模型,然后通过典型算例,模拟了成型工艺中温度场,固化度场的相互影响及对粘弹性复合材料网格结构应力场的影响.论文工作对复合材料网格结构软模成型共固化工艺参数优化具有一定的参考价值.     

复合材料RFI成形用树脂膜的成膜工艺性研究

针对先进复合材料树脂膜渗透成形技术(RFI)中的树脂膜,分析了其成形的基本过程,在测定树脂体系的基本粘度-温度关系基础上,采用树脂膜/离型纸的拉伸剪切实验方法测定了树脂膜的拉伸剪切强度,研究了树脂膜在不同温度及速度下的剪切载荷-位移关系及内聚破坏及界面破坏的转变温度范围.结果显示,破坏形式的转化是决定剪切强度-温度依赖性的关键.确定了实验树脂体系的成膜工艺区间的下限.     

树脂基复合材料在潜艇装备领域的应用现状

阐述了树脂基复合材料应用于潜艇装备的军事需求,梳理了国外树脂基复合材料在潜艇装备领域的应用情况,从总体设计、材料制备、加工制造、考核评价等四个技术领域分析了国外潜艇用树脂基复合材料的技术发展现状,并对树脂基复合材料在潜艇领域的应用前景进行了展望。     

先进复合材料在飞机结构中的应用

近年来,中国正在自主研发大型商用飞机,先进复合材料以其密度小、比强度/比模量高、耐高温性能好、耐疲劳性能优越等独特优点具有极大的应用潜力。对先进复合材料在飞机上应用及其发展历程进行了全面系统的回顾与总结,指出了复合材料在应用中存在的、急需解决的问题,并全面详细地介绍了飞机用复合材料的新进展,指出了未来复合材料可能的发展趋势,以供参考。     

MPI树脂基复合材料研究

简述了碳纤维增强 MPI树脂基复合材料的制造工艺。研究表明 :AS4 /MPI复合材料 371℃力学性能保持率 >5 0 % ,复合材料在 371℃、 10 0 h的失重率为 2 .2 5 % ,表明其具有较好的耐热氧化稳定性 (TOS)     

环氧-铜粉体系导电涂料的制备工艺

研制了一种以环氧树脂为基料的铜系导电涂料,讨论了固化剂用量、铜粉含量、钛酸酯偶联剂JSC的用量以及处理方法对涂料导电性能的影响,并分析了原因。结果表明,铜粉含量70%～75%,固化剂用量20%,偶联剂含量2%时,导电涂料的综合性能较好,涂层体积电阻率为0.12×10-4Ω·m,稳定性好。