Structural Design and Analysis of a Booster Arm Made of a Carbon Fiber Reinforced Epoxy Composite Material

An analysis of a booster arm made of a carbon fiber reinforced epoxy composite material is conducted by means of a finite element analysis method.The mechanical properties are also determined through stretching and compression performance tests.It is found that the surface treatment of the fibers causes the silane coupling agent to undergo a chemical reaction on the surface of the glass fiber.The used material succeeds in producing significant vibrations damping(vibration attenuation effect is superior to that obtained with conventional alloy materials).

Application Strategy of Carbon Fiber Composite Materials in Bridge Reconstruction Project

Initially,the materials used in the process of bridge construction were mainly wood,stone,etc.,and gradually the concrete,steel and other types of special materials currently in-use were developed.With the current vigorous development of science,technology and social economy in China,the development of bridge projects has also been accelerated to a large extent.In recent years,China has not only studied on how to strengthen the performance of concrete,steel and other materials in bridge projects,but also the performance of the recently developed smart,nano-,fibrous and other types of materials.This paper focuses on the application strategy of carbon fiber composite materials in bridge reconstruction projects to serve as a reference.

Smart Behavior of Carbon Fiber Reinforced Cement-based Composite

The electrical characteristics of cement-based material can be remarkably improved by the addition of short carbon fibers. Carbon fiber reinforced cement composite (CFRC) is an intrinsically smart material that can sense not only the stress and strain, but also the temperature. In this paper, variations of electrical resistivity with external applied load, and relation of thermoelectric force and temperature were investigated. Test results indicated that the electrical signal is related to the increase in the material volume resistivity during crack generation or propagation and the decrease in the resistivity during crack closure. Moreover, it was found that the fiber addition increased the linearity and reversibility of the Seebeck effect in the cement-based materials. The change of electrical characteristics reflects large amount of information of inner damage and temperature differential of composite, which can be used for stress-strain or thermal self-monitoring by embedding it in the concrete structures.

One-pot synthesis of Sb-Fe-carbon-fiber composites with in situ catalytic growth of carbon fibers

A Sb-Fe-carbon-fiber （CF） composite was prepared by a chemical vapor deposition （CVD） method with in situ growth of CFs us- ing Sb203/Fe2O3 as the precursor and acetylene （C2H2） as the carbon source. The Sb-Fe-CF composite was characterized by X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM） and transmission electron microscopy （TEM）, and its electrochemical per- formance was investigated by galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy. The Sb-Fe-CF composite shows a better cycling stability than the Sb-amorphous-carbon composite prepared by the same CVD method but using Sb2O3 as the precur- sor. Improvements in cycling stability of the Sb-Fe-CF composite can be attributed to the formation of three-dimensional network structure by CFs, which can connect Sb particles firmly. In addition, the CF layer can buffer the volume change effectively.

Piezoresistivity of Carbon Fiber Graphite Cement-based Composites with CCCW

The electrical conductivity and piezoresistivity of carbon fiber graphite cement-matrix composites（CFGCC） with carbon fiber content（1% by the weight of cement）,graphite powder contents （0%-50% by the weight of cement） and CCCW（cementitious capillary crystalline waterproofing materials,4% by the weight of cement） were studied.The experimental results showed that the relationship between the resistivity of CFGCC and the concentration of graphite powders had typical features of percolation phenomena.The percolation threshold was about 20%.A clear piezoresistive effect was observed in CFGCC with 1wt% of carbon fibers,20wt% or 30wt% of graphite powders under uniaxial compressive tests,indicating that this type of smart composites was a promising candidate for strain sensing.The measured gage factor （defined as the fractional change in resistance per unit strain） of CFGCC with graphite content of 20wt% and 30wt% were 37 and 22,respectively.With the addition of CCCW,the mechanical properties of CFGCC were improved,which benefited CFGCC piezoresistivity of stability.

Intumescent Flame-retardant Modification of Polypropylene/Carbon Fiber Composites

To improve the flame resistance of polypropylene(PP)/carbon fiber(CF)composite materials,triazine char-forming agent(TCA)was compounded with ammonium polyphosphate(APP)or modified APP(CS-APP)in a 2:1 ratio to prepare intumescent flame retardant(IFR)and the modified intumescent flame retardant(CS-IFR)in this paper.Flame retardancy and thermal degradation behaviors of the composites modified by IFR and CS-IFR were characterized by Fourier Transform Infrared(FTIR),contact angle measurement,oxygen index(OI),vertical burning tests(UL-94),thermogravimetric analyer(TGA),and thermogravimetric analyzer coupled with Fourier transform infrared(TG-FTIR).It was found that 25.0 phr of IFR and 24.0 phr of CS-IFR could improve the LOI value of PP/CF composites to 28.3%and 28.9%,respectively.At the same time,a UL-94 V-0 rating was achieved.The experimental results show that the IFR and CS-IFR prepared could effectively improve the flame retardancy and thermostability of PP/CF composites,and they would greatly expand the application range of PP/CF composite materials.

Experimental Research on Behavior of Composite Material Projectile Penetrating Concrete Target

Projectile made of carbon fiber composite material shell and metal warhead penetrates concrete target at speeds of 336,m/s,447,m/s and 517,m/s.The angles between the perpendicu-lar of target surface and projectile axis are 0°and 30°.The thickness of concrete target is 200,mm and the compression strength is 30 MPa.The experimental results indicate that the strength of composite material structure is high.Composite projectile can go through concrete tar-get without fiber segregation and breakage.The percent fill is 18.5% in the composite material projectile.It is about twice as that of metal projectile,if the density of metal is taken as 7.8,g/cm3.Comparing with metal projectile,low-density,high-strength composite material can lessen projec-tile weight,improve charge-weight ratio of detonator and enhance destructive powder.

Ablation Property of Ceramics/Carbon Fibers/Resin Novel Super-hybrid Composite

A novel super-hybrid composite (NSHC) is prepared with three-dimension reticulated SiC ceramic (3DRC), high performance carbon fibers and modified phenolic resin (BPR) in this paper. Ablation performance of super-hybrid composite is studied. The results show that the NSHC has less linear ablation rate compared with pure BPR and CF/BPR composite, for example, its linear ablation rate is 50% of CF/BPR at the same fiber content. Mass ablation rate of the NSHC is slightly lower than that of pure BPR and CF/BPR composite because of their difference in the density. Scanning electron microscopic analysis indicates that 3DRC can increase anti-erosion capacity of materials because its special reticulated structure can control the deformation of materials and strengthen the stability of integral structure.

Analysis on the Bonding Failure Mechanism of High Modulus Carbon Fiber Composites

In order to explore the bonding failure mechanism of high modulus carbon fiber composite materials,the tensile experiment and finite element numerical simulation for single-lap and bevel-lap joints of unidirectional laminates are carried out,and the stress distributions,the failure modes,and the damage contours are analyzed. The analysis shows that the main reason for the failure of the single-lap joint is that the stress concentration of the ply adjacent to the adhesive layer is serious owing to the modulus difference,and the stress cannot be effectively transmitted along the thickness direction of the laminate. When the tensile stress of the ply exceeds its ultimate strength in the loading process,the surface fiber will fail. Compared with the single-lap joint,the bevel-lap joint optimizes the stress transfer path along the thickness direction,allows each layer of the laminate to share the load,avoids the stress concentration of the surface layer,and improves the bearing capacity of the bevel-lap joint. The improved bearing capacity of the bevellap joint is twice as much as that of the single-lap joint. The research in this paper provides a new idea for the subsequent study of mechanical properties of adhesively bonded composite materials.

The impact of the new composite material technology on the performance of the tennis rackets

With the continues improving of people＇s living standards, more and more people work out in all kinds of sports fields beyond the busy work. On the other hand, the development of the modem competitive sports also requires that the sports experts should not only strive for the scientific training, but should also pay much attention on the improvement and development of the sports equipment at the same time, which makes the sports equipment market have achieved unprecedented prosperity. This paper introduces the application of the fiber reinforced composite materials in the field of sports equipment, which is described mainly from the advantages of the fiber reinforced composite materials used in sports equipment areas, and from the aspects of the principles of material selection, the product varieties, the application examples and the status.

Research on Properties of Carbon Fiber/Epoxy Resin Composite Material by Microwave Curing

Microwave irradiation was used to reduce the curing time of carbon fiber/epoxy resin composite material.The properties of carbon fiber/epoxy resin composite material under microwave curing were investigated by thermogravimetry(TG),dynamic mechanical analysis(DMA),impact strength test and scanning electron microscope(SEM).The results show that composite materials patch have high thermal stability after microwave curing.The initial degradation temperature is 330.9℃,the maximum thermal decomposition rate is at 368.1℃.When the layer of composite materials patchis 4 layers,the dynamic mechanical properties are the best after microwave curing.The initial storage modulus is 43.2 GPa,increased 28.3 GPa and 27.1 GPa than 3 layers and 5 layers,the glass transition temperature(Tg)is 67.48℃,increased about 12 ℃than 3 layers and 5 layers.Microwave curing can significantly improve the infiltration capacity of epoxy resin,enhance interfacial bonding,and increase the impact strength of composite patch.Under microwave curing,the impact strength of 3,4,5-layers composite material patches increases 35.9%,6.4% and 15.1%,respectively than heating curing.The SEM analysis of impact fracture surface shows that microwave curing can improve the interface of carbon fiber and epoxy resin.

含缺陷管道碳纤维复合材料补强数值模拟研究

当代石油、天然气等能源的主要运输方式为管道运输,管道在长期使用时会产生各种缺陷,这些缺陷将对管道的结构和强度产生影响。目前先进的管道修复技术为复合材料补强技术,其中碳纤维复合材料是较优的选择。为了测试有/无碳纤维补强管道缺陷处的效果,开展了不同层数碳纤维复合材料的拉伸实验研究,结合ANSYS数值模拟探究了修复前后不同缺陷管道在承载时的应力、应变分布,分析了修复补强效果的影响因素。结果表明:缺陷减薄厚度对管道的应力、应变状态影响较大,碳纤维复合材料修复技术能在减小管道缺陷处应力、应变的同时优化其应力、应变分布,可以通过增加碳纤维修复层数来提升修复效果,相关研究对于管道的修复补强有一定指导意义。

阵列式碳纤维复合材料的制备与微波吸收机理研究

以碳纤维为代表的碳材料具有质轻、导电性好、化学稳定性强等突出的物理化学性质,将其作为吸波剂使用可以提升材料的吸波性能、使用寿命并有效降低重量。通过“电场取向优化+基体灌封固化”的工艺完成了不同组分阵列式碳纤维复合材料的制备,采用SEM、FT-IR等手段对材料的形貌和化学成分进行表征,利用矢量网络分析仪对材料在2~18 GHz频段内的复介电常数和复磁导率进行表征,分析了微观结构对材料电磁参数、界面阻抗匹配及电磁波吸收性能的影响规律,最后研究碳纤维空间排布形式、复配粉体成分对其吸波性能的影响机制。结果表明,材料的电磁损耗机制由电介质损耗、干涉相消、界面极化弛豫、磁损耗共同构成;当复合材料厚度为2.0 mm时,反射率<-10 dB(6.1~7.6 GHz),在6.5 GHz处最大衰减值为-15.2 dB,热导率达到3.2 W/(m·K);验证所制备的材料在满足电磁波吸收功能的同时还具有一定的导热性。

碳纤维复材结构网球器械接头的胶接强度性能表征

针对网球器械用碳纤维复合材料胶接连接,以超声机械振动方法胶接处理了网球器械用碳纤维复合材料,并测试分析了碳纤维复合材料胶接强度。结果表明,超声机械振动胶接工艺参数直接影响着网球器械用碳纤维复合材料的胶接强度,其振动时间为21s、振动压力为0.35 MPa、振动位置为27 mm、振幅为57μm时,网球器械用碳纤维复合材料胶接强度最高;相较于未超声机械振动对照组,基于正交实验优化的超声机械振动组的碳纤维复合材料胶接强度更高,且试样破坏后胶层截面位置缝隙非常小,胶接强度分散性较小,胶接性能更加稳定。

铁粉/碳纤维增强树脂复合材料的制备 及脆化损伤研究

将偶联剂改性纳米铁(Fe)粉与预处理后的碳纤维混合,浸润于环氧树脂基料中,经过搅拌混合制备纳米Fe粉/碳纤维增强树脂复合材料,研究了复合材料在高温老化、水浸老化环境下的脆化损伤行为。结果表明:树脂受到高温老化和水浸泡老化后会出现脆化损伤,碳纤维和纳米Fe粉加入会对该损伤有一定抑制;加入质量分数为4.0%的纳米Fe粉后,随着高温老化时间延长,碳纤维质量分数为3.0%的纳米Fe粉/碳纤维增强复合材料的拉伸强度、断裂韧性下降幅度较小,同时脆化损伤后树脂与纳米Fe粉、碳纤维仍结合紧密;碳纤维质量分数为3.0%、纳米Fe粉质量分数为4.0%的纳米Fe粉/碳纤维增强复合材料经水浸老化后,断裂韧性仍旧保持较高水平。

碳纤维复合材料在建筑加固工程中的应用

碳纤维复合材料具有强度高、质量轻等特点,在建筑加固工程中应用的碳纤维材料包含碳纤维板及碳纤维布两种,其加固操作简单、适用面广,相比传统加固方式优势明显。本文主要分析了碳纤维复合材料的加固原理及其优势,介绍了碳纤维复合材料在建筑加固中所应用的内嵌入式及外贴式加固方法,并对未来的应用做出展望,以期能够为碳纤维复合材料在建筑加固工程中的使用提供借鉴意义。

浅谈建筑结构加固工艺

我国在基础建设快速发展的阶段,进一步加大了对基础设施建设的投入,从而加快了建筑业的发展,充分发挥国家科技力量的支撑作用,相继修建了各种类型的道路、桥梁、高楼、会展中心、重大水利工程等。由于受到自然灾害、空气影响等,这些建筑的结构往往出现过早老化的情况。据相关统计数据显示,全国城镇需要开展加固工作的民用建筑有30亿平方米,其中亟待修复加固处理的建筑有10亿平方米。如何对这些老旧建筑检测加固,需要进行研究探讨。

短切碳纤维增强MC尼龙复合材料的制备与性能

MC尼龙是一种已得到广泛应用的重要的工程塑料,但存在尺寸稳定性较差、热稳定性不高和重载下强度欠佳等缺点。本研究采用短切碳纤维(SCF)作为改性剂,探索研究了SCF/MC尼龙复合材料的制备工艺,研究了不同的SCF含量对复合材料密度、转化率、机械性能、摩擦性能及结晶度的影响。结果表明:在0~20%SCF含量范围内,复合材料的密度及拉伸强度表现为先增大后减少;转化率和冲击强度为20%SCF复合材料最为突出;而摩擦系数、磨损量在加入SCF后呈现先减少后增加的趋势。在10%SCF含量时,材料表现出较好的摩擦性能,同时结晶温度增大到182.95℃,结晶度为35.57%。研究结果证实通过添加适当比例的SCF改性剂可以有效改善MC尼龙的性能,这为进一步开发满足某些特殊螺旋传动下的新型复合材料做了有益尝试。

脉冲激光改性碳纤维复合材料及其金属化研究

目的选择性地实现碳纤维复合材料(Carbon fiber reinforced plastic,CFRP)表面良好的导电性,满足它在共形天线上的应用。方法采用波长为1064 nm的纳秒脉冲激光器对惰性极高的CFRP表面进行表面改性处理,并结合化学镀铜技术,制备激光改性碳纤维复合材料表面金属层。利用扫描电镜、X射线光电子能谱仪对改性后的材料表面进行表征,利用焊点拉脱方法表征金属层结合力。结果研究表明,激光能量密度越高,则CFRP基材表面树脂被去除得越多;激光搭接率越大,则碳纤维束表面越粗糙;在适当的激光能量密度(60 J/cm^(2))和横/纵向搭接率(50%)下,会产生大量的极性化学基团。当激光能量密度为10~100 J/cm^(2)、激光搭接率为0%时,CFRP表面镀铜层的结合强度为0.57~3.16 MPa,且激光能量密度与镀层结合强度呈正相关。当激光能量密度为60 J/cm^(2)、激光搭接率为−100%~90%时,CFRP表面镀铜层的结合强度为0.19~3.24 MPa,且激光搭接率与镀层结合强度呈正相关。结论脉冲红外纳秒激光在一定能量密度和搭接率的条件下,可改变碳纤维表面形貌、化学成分,实现金属层的制备。

不同铺层数平纹碳纤维力学特性分析

为明确面密度为200g/m^(2)的3K平纹碳纤维的力学特性,分别进行不同铺层数下碳纤维树脂基复合材料的拉伸、弯曲和冲压式剪切实验。结果表明:试样的损伤形式为断口处的分层、纤维从基体中拔出和断裂、垂直于载荷方向上的纤维束撕裂、基体之间的挤压、纤维的剪切断裂、基体的挤压变形。拉伸和弯曲试样的位移载荷曲线的起始阶段是线性的,弯曲试样的位移载荷曲线的起始阶段是非线性的。在2—12层的铺层数变化范围内,所有试样的铺层数载荷曲线呈现线性变化,试样承受弯曲载荷的能力较弱。