纳米黏土改性碳纤维复合材料的研究进展

本文就碳纤维/黏土/环氧树脂复合材料的制备方法、成型工艺及性能的研究进展进行了综述,指出了目前黏土在环氧树脂中的分散方法以及碳纤维/黏土/环氧树脂复合材料的成型工艺研究中存在的问题。     

基于频率识别纤维增强复合材料弧形板分层损伤

利用损伤发生前后的频率变化识别纤维增强复合材料(FRP)弧形层合板中的分层损伤。首先建立含分层损伤的FRP弧形板有限元模型,在不同分层损伤情况下计算弧形板的频率,与无损伤弧形板比较后得到频率改变量。分别使用遗传算法、有代理模型的遗传算法和人工神经网络等三种逆向检测算法对分层的界面、位置和大小进行识别,发现遗传算法比人工神经网络的预测精度要高很多,而有代理模型的遗传算法由于采用近似模型替代遗传算法中的有限元模型,大大提高了算法的运算效率,在保证精度的前提下,损伤识别的时间是直接遗传算法的1/163。     

Manufacturing Influence on the Delamination Fracture Behavior of the T800H/3900-2 Carbon Fiber Reinforced Polymer Composites

'Torayca' T800H/3900-2 is the first material qualified on Boeing Material Specification (BMS 8-276) which utilizes the thermoplastic-particulate interlayer toughening technology. Two manufacturing processes, the autoclave process and the fast heating rated Quickstep™ process, were employed to cure this material. The Quickstep process is a unique composite production technology which utilizes the fast heat transfer rate of fluid to heat and cure polymer composite components. The manufacturing influence on the mode I delamination fracture toughness of laminates was investigated by performing double cantilever beam tests. The composite specimens fabricated by two processes exhibited dissimilar delamination resistance curves (R-curves) under mode I loading. The initial value of fracture toughness G_IC-INIT was 564 J/m² for the autoclave specimens and 527 J/m² for the Quickstep specimens. However, the average propagation fracture toughness G_IC-PROP was 783 J/m² for the Quickstep specimens, which was 2.6 times of that for the autoclave specimens. The mechanism of fracture occurred during delamination was studied under scanning electron microscope (SEM). Three types of fracture were observed: the interlayer fracture, the interface fracture, and the intralaminar fracture. These three types of fracture played different roles in affecting the delamination resistance curves during the crack growth. More fiber bridging was found in the process of delamination for the Quickstep specimens. Better fiber/matrix adhesion was found in the Quickstep specimens by conducting indentation-debond tests.     

导热型碳纤维增强聚合物基复合材料的研究进展

综述了导热型连续碳纤维增强聚合物基复合材料(CFRP)的研究与应用现状和进展,阐述了CFRP的声子导热和光子导热机理,介绍了不同铺层角度和铺层比的CFRP面内和厚度方向热导率计算模型及测试方法,分析了环氧树脂、氰酸酯、双马来酰亚胺等3类树脂体系和聚丙烯腈基(PAN)碳纤维、中间相沥青基碳纤维、气相生长碳纤维、碳纳米管纤维等4类增强体以及工艺方法等因素对CFRP热导率的影响。     

Anisotropic Dielectric Properties of Carbon Fiber Reinforced Polymer Composites during Microwave Curing

Microwave cuing technology is a promising alternative to conventional autoclave curing technology in high efficient and energy saving processing of polymer composites. Dielectric properties of composites are key parameters related to the energy conversion efficiency during the microwave curing process. However, existing methods of dielectric measurement cannot be applied to the microwave curing process. This paper presented an offline test method to solve this problem. Firstly, a kinetics model of the polymer composites under microwave curing was established based on differential scanning calorimetry to describe the whole curing process. Then several specially designed samples of different feature cure degrees were prepared and used to reflect the dielectric properties of the composite during microwave curing. It was demonstrated to be a feasible plan for both test accuracy and efficiency through extensive experimental research. Based on this method, the anisotropic complex permittivity of a carbon fiber/epoxy composite during microwave curing was accurately determined. Statistical results indicated that both the dielectric constant and dielectric loss of the composite increased at the initial curing stage, peaked at the maximum reaction rate point and decreased finally during the microwave curing process. Corresponding mechanism has also been systematically investigated in this work.     

碳纳米管/连续纤维增强树脂基复合材料力学性能设计

本文综述了碳纳米管/连续纤维增强树脂基复合材料力学性能影响因素,同时对目前公开发表的几种预测碳纳米管/连续纤维增强复合材料模量及破坏强度的分析方法进行了介绍与分析。最后,对今后研究动向进行了展望。     

Objective Surface Evaluation of Fiber Reinforced Polymer Composites

The mechanical properties of advanced composites are essential for their structural performance, but the surface finish on exterior composite panels is of critical importance for customer satisfaction. This paper describes the application of wavelet texture analysis (WTA) to the task of automatically classifying the surface finish properties of two fiber reinforced polymer (FRP) composite construction types (clear resin and gel-coat) into three quality grades. Samples were imaged and wavelet multi-scale decomposition was used to create a visual texture representation of the sample, capturing image features at different scales and orientations. Principal components analysis was used to reduce the dimensionality of the texture feature vector, permitting successful classification of the samples using only the first principal component. This work extends and further validates the feasibility of this approach as the basis for automated non-contact classification of composite surface finish using image analysis.     

AZ-1改性炭纤维/聚三唑复合材料界面研究

研究了一种用氮丙啶处理炭纤维的方法在新型聚三唑树脂复合材料中的界面作用效果和作用机理.用硝酸氧化处理炭纤维,再引入分子结构中含氮丙啶环的化合物AZ-1,通过化学手段对炭纤维进行改性.结果表明,经改性后炭纤维增强聚三唑树脂复合材料比未处理复合材料的层间剪切强度提高86%.AFM,SEM和接触角测试表明化学改性增加了炭纤维...     

Eddy Current Testing of Delamination in Carbon Fiber Reinforced Polymer (CFRP): A Finite Element Analysis

Carbon fiber reinforced polymer (CFRP) is widely used thanks to its excellent material properties. However, damages, especially delamination, can cause significant reduction in strength of CFRP structures. This article attempts to study the nondestructive testing of delamination using eddy current (EC) method. To this end, we design a novel probe consisting of dual coplanar rectangular coils placed perpendicular to sample surface, and make use of the vertical sections of the coils to induce vertical EC in the test sample. Perturbation of the vertical EC by delamination gives us a chance to detect delamination. Simulation results by the finite element method demonstrate the feasibility of the proposed method.     

碳纤维增强热塑性聚酰亚胺及其复合材料

采用双螺杆共混挤出法,在热塑性聚酰亚胺(TPI)树脂中添加碳纤维(CF)进行复合增强,实验研究了碳纤维种类、加入量及成型方法对复合材料力学性能的影响.结果表明:碳纤维的加入能显著提高材料的常温和高温力学强度,并与碳纤维种类有关;复合材料的拉伸和弯曲强度均随着碳纤维加入量的增大而升高;相对于模压成型方法,注塑成型可获得更高强度的复合材料.由扫描电镜(SEM)观察到的材料拉伸和弯曲断面的微结构形貌,初步探讨了碳纤维的增强机理.     

热压辅助先驱体裂解制备三维编织碳纤维增强Si-O-C复合材料的研究

以聚硅氧烷为先驱体 ,采用先驱体转化法制备三维编织 Cf/ Si- O- C复合材料。研究发现 ,第一次裂解时采用热压辅助可以明显提高材料的致密度和力学性能。第一次在 1 6 0 0℃ / 1 0 MPa的条件下热压裂解 5 min,后续真空浸渍 -常压裂解处理六个周期所制得的材料具有较高的力学性能 ,其弯曲强度和断裂韧性分别为 5 0 2 MPa,2 3 .7MPa.m1 /2 。讨论了制备工艺对材料结构和性能的影响 ,理想的界面结构与较高的致密度是其具有高性能的主要原因     

Piezoresistivity in Carbon Fiber Reinforced Cement Based Composites

The results of some interesting investigation on the piezoresistivity of carbon fiber reinforced cement based composites (CFRC) are presented with the prospect of developing a new nondestructive testing method to assess the integrity of the composite. The addition of short carbon fibers to cement-based mortar or concrete improves the structural performance and at the same time significantly decreases the bulk electrical resistivity. This makes CFRC responsive to the smart behavior by measuring the resistance change with uniaxial pressure. The piezoresistivity of CFRC under different stress was studied, at the same time the damage occurring inner specimens was detected by acoustic emission as well. Test results show that there exists a marking pressure dependence of the conductivity in CFRC, in which the so-called negative pressure coefficient of resistive (NPCR) and positive pressure coefficient of resistive (PPCR) are observed under low and high pressure. Under constant pressures, time-dependent resisti     

碳纤维水泥基材料的电热效应

研究了碳纤维水泥基材料(CFRC)的电热效应,包括最大温升与外加功率的关系、升温规律和降温规律等。结果表明:CFRC材料的最大温升与其外加功率满足良好的线性关系;其升温曲线和降温曲线可由特定的表达式来描述,且外加功率越大,升温速率越大。这一研究对碳纤维水泥基材料在海工工程上的应用具有重要意义。     

Laser Surface Modification of Carbon Fiber Reinforced Composites

The removal of top resin layer is an essential task prior to adhesive bonding of carbon fiber reinforced polymer (CFRP) composites. This paper investigates the technical feasibility of using a low power continuous wave carbon dioxide laser for removing the top resin layer of CFRP without damaging the underlying fiber. The operating window and damaging threshold were experimentally determined. Irradiating the CFRP surface at a power of 14 W, scanning speed of 880 mm/sec, and a beam overlap of 25% provides an optimal thermal condition for removal of top resin layer. A finite element model was used to explain the removal mechanisms.     

碳纤维增强聚醚醚酮复合材料研究进展

近年来,碳纤维增强热塑性复合材料（CFRTP）,尤其是碳纤维/聚醚醚酮（CF/PEEK）复合材料以其优异的综合性能受到了大量关注。高性能碳纤维/聚醚醚酮复合材料具有强度大、韧性好、使用温度高等诸多优点,在航空航天、机械、电气、汽车工业和生物工程等领域得到了广泛的应用。针对近年的研究热点,对碳纤维/聚醚醚酮复合材料在界面性能、力学性能、生物相容性、成型工艺、失效机理等方面的研究进展进行了综述,为材料的制备技术研究及产业化应用奠定基础。      

纤维增强聚合物基复合材料的回收与再资源化

综述了纤维增强聚合物与纤维材料的分离、回收和再资源化方法,并作简明展望.     

碳纤维增强复合材料应力检测技术

碳纤维增强复合材料在制备、加工到装配、服役过程中,由于热膨胀不匹配等原因会导致材料内部出现分层、裂纹等缺陷,这些缺陷往往使材料处于一定的应力状态。这些应力状态有些对结构有益,而大多会使分层、裂纹等缺陷加剧进而造成结构强度和稳定性的大幅下降,在结构设计过程中必须充分认识有害的残余应力。精确快速地检测复合材料所处的应力状态,对于准确评估结构的强度、稳定性和使用寿命至关重要。总结了有损和无损应力检测技术的研究现状,并通过分析不同检测方法的优势与不足,指出了今后碳纤维增强复合材料应力检测研究工作的发展趋势。     

电镀镍碳纤维增强铝基复合材料

提出一种碳纤维表面电镀镍的方法,通过正交实验优化了电镀镍配方及工艺条件,并研究了镀层的显微组织及镀液的成分、电流密度、电镀时间等工艺条件对沉镍速率和镀层质量的影响,并探讨了沉镍机理.用镀镍碳纤维制备铝基复合材料,观测碳纤维与铝的复合效果.