基于PMAC的多层纤维预浸坯超声波切割机构设计与控制

针对碳纤维预浸坯的结构特性以及在传统切割中存在的问题,研究设计了一种超声波切割装置,以PC+运动控制卡作为超声波切割机构的控制系统,伺服电机控制超声波切割刀在工作台上的运动。重点介绍了对C轴刀具旋转运动的控制,以保证超声波切割刀的刀刃方向始终与切割图形的切线方向一致。通过上位机编程软件编程,PMAC运动控制卡发出指令到伺服驱动器,驱动电机进给运动,从而实现自动化切割。该切割系统和传统切割方式相比,具有效率高、切割质量好等优点。     

预浸料技术的新进展

本文根据复合材料低成本制造技术，介绍了预浸料技术的新进展，包括可常温储存的预浸料；低温固化高温使用的预浸料；大丝束碳纤维预浸料和快速固化预浸料。     

Continuous reactor preparation of thermoplastic modified epoxy‐amine prepolymers

This paper describes a new continuous reactor method to prepare thermoplastic modified epoxy prepolymers for aerospace prepregs with the aim of replacing traditional batch reactors. Compared with batch reactors, the continuous reactor is capable of producing epoxy prepolymers through simultaneous dissolution of polyethersulfone (PES) and 4,4′‐diaminodiphenylsulfone in tetraglycidyl‐4,4′‐ diaminodiphenylmethane (TGDDM). In addition, concurrent chain extension reactions advance prepolymer molecular weights to desired viscosities in less than 2 min of mean residence time. Optical micrographs were used to define how process temperature influences PES dissolution in TGDDM in a continuous reactor. Kinetic studies confirmed that the chain extension reaction in a continuous reactor is similar to that in a batch reactor, and the molecular weights and viscosities of prepolymers were readily controlled through reaction kinetics. Atomic force microscopy was used to confirm similar cured network morphologies for formulations prepared from batch and continuous reactors. Additionally tensile strength, tensile modulus and fracture toughness analyses concluded that mechanical properties of cured epoxy matrices produced from the two reactors were equivalent. © 2014 Society of Chemical Industry     

Effect of hygrothermal conditioning on the energy release rate and failure mechanism of metal only adherend-glass fibre prepreg co-cured single lap joints

Abstract

Fibre-reinforced composite materials are extensively used in repair and rehabilitation of oil and gas metal infrastructures which are largely exposed to water and hydrocarbon. An important aspect to this is applying adequate surface preparation to the metal to ensure a durable bond between the composite and metal substrate. In this paper, mild steel surface was prepared using grit blasting and single lap joint (SLJ) test specimens were manufactured and tested to investigate the adhesion in terms of total energy release rate (G_T) of the interface between mild steel adherend and glass fibre prepreg. An out-of-water usable epoxy resin primer was incorporated to join mild steel adherend with glass fibre prepreg by curing at a temperature of 55 °C for 48 h. Upon durability testing of the SLJ specimens using hygrothermal conditioning at a temperature of 55 °C for 1000 h, the experimental G_T values were seen to reduce significantly. Comparatively lower amount of cohesive failure and increased amount of swelling or delamination of the adhesive was observed for conditioned SLJ specimens when compared to controlled SLJ specimens. Furthermore, the experimental G_T values were found to correlate well with an analytical adhesive interface model.     

预浸料在RTM工艺中的应用研究

采用共固化RTM工艺制备了碳纤维增强环氧树脂5284RTM/5228A复合材料层板。通过超声C扫描和显微分析法评价了层板的内部质量,通过短梁剪切强度和弯曲性能研究了层板的力学性能,利用DMA评价了层板的耐热性能。结果表明,所制备的层板内部质量良好,预浸料层的预处理对层板的内部质量、力学性能和耐热性能都没有明显影响,而热固性中介层的引入虽然不会影响体系的内部质量和力学性能,但会使层板的耐热性能降低。     

碳纤维/环氧预浸料的热固化工艺研究

以先进拉挤(Advanced Pultrution)[1]ADP成型技术为研究背景,借助差示扫描量热法(DSC)对USN12500碳纤维/环氧预浸料固化所涉及的温度和时间进行了研究与分析。以弯曲强度作为考察指标设计正交试验,优选了模拟的拉挤成型固化工艺参数。试验结果表明,①后固化温度下的保温时间对制品的力学性能影响最大,预处理温度下的保温时间影响最小;②预处理温度80℃下处理25min、热压温度130℃下保温保压25min以及后固化温度150℃下保温1.5h为本组试验的优方案。     

连续碳纤维热塑性复合材料制备工艺研究

对近年来的碳纤维热塑性复合材料预浸料制备技术、成型工艺及其在电子电气中的应用现状进行了综合论述．     

基于机器视觉的碳纤维预浸料表面缺陷检测方法

针对碳纤维预浸料表面缺陷人工检测方法效率低、成本高、实时性差等问题,提出基于机器视觉的碳纤维预浸料表面缺陷自动检测方法。首先,在碳纤维预浸料生产线上,采用2台高分辨率线扫描相机快速连续采集图像,从中随机选择带有缺陷的图像1 000张;其次,基于大气光散射模型对图像进行去雾增强处理,以消除白色树脂的干扰;然后,改进具有19个卷积层和5个最大值池化层的YOLOv2目标检测算法,用于缺陷的检测;最后,对预处理后的图像进行网络训练提取图像特征,识别图像目标,并对训练好的网络进行实验验证。结果表明:该方法在复杂的工业环境下,具有较高的识别精度和鲁棒性,识别成功率达到94%以上,且每张图像的检测时间不超过 0.1 s,可满足工业生产中精度和实时性要求。     

3232/Rc10 800预浸带的试制

选择了3232树脂和Rc10800玻璃粗纱，研究了各浸渍工艺参数对预浸带质量的影响，并试制出合格产品。     

单向碳纤维/环氧树脂预浸料的热响应行为

实验探究单向碳纤维/环氧树脂预浸料在不同高温环境及不同方向的热响应行为.研究表明,单向碳纤维/环氧树脂预浸料在低于230℃的高温环境下,热响应温度、导热系数随热响应时间的增加而增大,其后趋于平稳;在高于230℃的高温环境下,热响应温度出现峰值,材料逐渐受损,热响应行为复杂.此外,研究得到单向碳纤维/环氧树脂预浸料在平面...