3D立体机织物及其复合材料

介绍了3D立体机织物的机织结构、织造技术及复合材料的研制与开发进程,对最近发展起来的空芯夹芯结构预制件、近形3D机织预制件的特点和用途作了较为具体的说明,并从3D机织增强复合材料的性能特点方面阐述了这类材料广泛的应用领域。     

三维机织物的织造

纤维增强复合材料由于具有优良的材料功能,被广泛用作为结构材料。三维(3D)复合材料中,3D织物用做为预构件。不少研究报导了具有矩形截面织物或三维五轴向(3D/5A)织物的制造方法,但是在一台织机上如何生产这两种织物却鲜有报导。     

3D机织物增强复合材料板的力学性能

以玻璃纤维为原料 ,在普通平面织机上试织成各种结构的 3D机织物 ,并用环氧 -聚酰胺树脂体系 ,通过手糊成型工艺制得各种结构的复合材料板材。经性能测试 ,3D机织物增强复合材料板材的层间剪切性能与抗冲击性能显著优于层合板     

管道修复用管状机织物复合材料的增强体结构设计

管状机织物增强复合材料应用于管道修复领域,以非开挖方法修复管道代替传统的全面开挖更换新管,不仅方便、经济而且环保。针对待修管道对管状机织物增强复合材料强度、厚度与管径的要求,对管状机织物增强复合材料的增强体即管状织物的结构与织造工艺进行了设计,并采用SPSS软件对管状织物的热缩性能进行了分析,建立了反映热缩时间、热缩温度与织物缩率之间关系的数学模型,从而指导管状机织物增强复合材料的管径设计,据此可重新修正织造工艺参数,为管状机织物增强复合材料的生产与应用提供理论依据。     

3D机织物拉伸强度理论研究现状与发展

将复合材料强度这一概念引入到作为复合材料预制件的三维(3D)机织物上,综述近年来对于3D机织复合材料及其预制件拉伸性能研究的代表性文献,阐述在机织物强力及复合材料强度研究理论中与预制件强度研究相关或者类似的理论,指出3D机织物拉伸试验研究的趋势。     

3D机织立体机织预成形体及其复合材料的研制

本项目采用增强纤维(包括玻璃纤维、碳纤维、芳纶纤维、高强聚乙烯等)或增强纤维与热塑性树脂纤维所组成的混合纤维束,构建3D机织结构,研制渐变形、圆形、平板状及空芯结构等截面立体机织预成形体,用于试制3D机织物增强高性能复合材料,     

玻璃纤维增强复合材料棒材的性能研究

以玻璃纤维为原料，在普通平面织机上试织成功了圆形截面3D机织物。并采用手糊成型工艺，以不饱和聚酯树脂为基体，制得了单向纤维束增强复合材料棒材和圆形截面3D机织物增强复合材料棒材；对这些棒材的性能进行了测试与分析，结果表明：后者的抗冲击强度、层间剪切强度显著优于前者。     

2.5D机织复合材料的设计与织造

介绍了2.5D机织复合材料的特点及其在国内外的应用现状,重点研究了浅交直联、浅交弯联两种典型2.5D结构机织物的设计与织造过程,探讨了织物设计过程中织物层数、总经根数等相关参数的确定方法,并对织造过程中出现的问题进行了分析.     

三维间隔织物轻质复合材料的力学性能

将3D间隔织物与轻质聚氨酯相结合,制备出3D经编间隔织物复合材料。对不同基体密度与增强体规格的3D间隔织物复合材料进行三点弯曲测试,研究其结构参数对力与位移曲线的影响;并对其抗冲击性能进行评价,获取影响复合材料冲击防护性能的因素。结果表明：基体密度对三维间隔织物复合材料力学性能的影响十分显著,基体密度越大,3D经编间隔织物复合材料的弯曲应力和弯曲强度越大,抗弯曲能力也越强,而可塑性越差,柔韧性越差;冲击吸收的冲击力逐渐减少,导致复合材料的抗冲击恢复性越差。     

3D弹性机织物的织造工艺

文章通过对现有3D立体机织物织造方法的分析,讨论了3D弹性机织物的织造工艺及注意的问题,并对该织物进行了小样试织.对3D弹性机织物的试织,充分表明了利用中间层纱线数量的增多、结构的变化以及组织的配合来实现织物较好弹性性能要求的方法是可行的,而且对工艺、设备稍加改进,就可以实现工业化生产.     

Mechanical properties improvement of silane addition epoxy/3D orthogonal woven composite material

In this study, the influence of silane addition on mechanical properties of epoxy/3D orthogonal glass fiber woven composite was studied. The KH560 silane modification composite specimen reinforced with 3D orthogonal woven fabric/epoxy was manufactured by means of Resin Infusion under Flexible Tooling. The mechanical properties of the epoxy/3D glass fiber woven composites were characterized by tensile and bending tests. The tensile and bending properties of silane-modified 3D orthogonal woven glass composite in warp and weft directions were compared with the pristine or epoxy/glass composite material not coupled using silane. The results show that the tensile and bending properties in warp and weft directions have been improved due to the silane addition. The bonding strength between the fiber and matrix was improved and the delamination and debonding between fiber and matrix was retarded and shifted to cohesive failure of the matrix due to the silane modification. Electron microscopy of the fracture and failure modes of the test specimens were used to support the results and conclusions.     

The mechanical performance of plain and plain derivative woven fabrics reinforced composites: tensile and impact properties

In this work, the mechanical performance of the plain and plain derivative woven fabric reinforced composites, were investigated. Tensile strength, modulus of elasticity, elongation at break and poison ratio values of the composites were found by tensile tests. In addition, drop-weight impact tests were performed at several impact energies: 15, 20, 25, 30 and 35 J in order to characterize the impact resistance, and damage mechanisms of the composite plates. The results reveal that the weaving pattern affects the tensile properties and the impact behaviour of the composites. It is observed that 2/2 matt woven fabric reinforced composite showed the best performance in tensile tests along warp direction; whereas, 2/2 warp rib woven fabric reinforced composite showed the best performance during tensile tests in weft direction. It is also observed that 3/1 matt woven fabric reinforced composite absorbs more energy for perforation than the others.     

玻璃纤维多轴向经编复合材料的制备及拉伸性能研究

以环氧树脂为基体,分别以玻璃纤维多轴向经编针织物和玻璃纤维机织物作为增强材料,通过手糊法制备复合材料,并通过试验对比研究两种复合材料的拉伸性能。结果表明,经编复合材料沿各个轴向的拉伸强度比复合前多轴向经编针织物及机织复合材料的强度均有明显提高,增幅均在50%以上,说明多轴向经编复合材料具有更优异的力学性能。这为进一步扩大玻璃纤维多轴向经编复合材料的应用领域提供了有力证据。     

三维正交整体夹芯机织物的结构设计及织造

以正交结构为基本的三维结构单元,通过改变空心各边的长度和厚度,设计了多种经向截面为六边形的三维整体夹芯机织物结构,并在改造的普通织机上织造成功。在此基础上对试样的结构特点进行对比分析,同时探讨了三维正交夹芯机织物孔形尺寸的影响因素,比较了各种三维整体夹芯机织物试样的结构特点及织造方法。该研究为三维整体夹芯机织物的结构设计提供了参考,设计的多种三维夹芯机织物为蜂窝结构复合材料提供了性能良好的增强体。     

三维正交机织物织造及复合材料成型工艺研究

详细阐述三维正交机织物的结构特征、织造原理及织造工艺,以三维正交机织物为增强体、环氧树脂为基体,采用真空辅助树脂传递模塑(VARTM)工艺成型,制成复合材料,并分析其内部结构。结果表明:由普通织机改造的多综眼多剑杆织机可以织造三维正交机织物,成型后复合材料内的纱线形状和位置未发生明显变化,树脂较好地渗透到织物内部,复合材料具有较高的纤维体积分数。研究结果为进一步研究三维正交机织复合材料的力学性能及应用奠定了基础。     

3D woven green composites from textile waste: mechanical performance

Application of textile waste for development of value added green composites has been carried out in this work. Textile fabric waste is collected from various sources. These waste materials are garneted, so as to produce loose fibrous material, subsequently this fibrous material was converted into twisted strand for manufacturing of 3D woven preforms for production of composites. Twisted strands are converted into orthogonal 3D woven structure. The fibers extracted from waste material are combined with polypropylene in 60/40 proportion. Composites of various specifications are developed to examine their end-use applications. These composite materials are characterized for their mechanical behavior to find out the response against tensile loading, flexural stress, and impact force. The effects of moisture absorption on mechanical properties of composites are investigated. 3D woven fabric reinforced composites produced by using waste fiber yarn and normal cotton OE yarn do not exhibit any significant difference in the mechanical behavior of composite. This result confirmed that waste material can be safely used as reinforcing structure in green composite manufacturing.     

中心切口对机织物增强柔性复合材料破坏过程与拉伸性能的影响

对预置中心裂纹切口和圆形切口机织物增强柔性复合材料在低速拉伸条件下的力学性能进行测试,随后对切口试样的破坏过程和拉伸曲线进行对比分析,对切口试样的缺口敏感性、拉伸模量和屈服强度随切口强度比的变化趋势进行研究。试验结果表明,织物增强柔性复合材料具有强烈的缺口敏感性,相对于中心圆形切口,机织物增强柔性复合材料对中心裂纹切口较为敏感。切口试样的拉伸模量和屈服强度随切口尺寸比的变化趋势表明,"切口强化"效应可用拉伸模量和屈服强度的强化来间接描述。     

机织物增强双层柔性复合材料拉伸异向性能及其失效准则

为了进一步研究织物增强双层柔性复合材料的力学性能,对偏轴向试样的单向拉伸性能进行了实验分析,研究了材料的拉伸破坏机理,并比较了两种强度失效准则下的预测值。结果表明：与机织物膜结构材料相比,该种材料表现出更加明显的各向异性;同时发现,相对于Tsai-Hill 强度失效准则,调和余弦级数强度失效准能较好地适应各种破坏模式下失效强度的预测,且该种材料的拉伸性能指标之间表现出非同相特性。     

基于气缸的三维机织增强体织造系统设计

为在经纱方向引入贯穿织物厚度的接结纱从而提升机织增强复合材料层间性能,以三维正交无卷曲机织增强体为对象,设计了一种窄幅三维机织织造系统。采用气缸作为开口、引纬和打纬的主要驱动部件,实现多重综框的独立开口运动与管状多剑杆机构的多层梭口同时引纬运动,并在可编程控制器上实现各机构协调运作,使经纬纱垂直平铺,接结纱与纬纱交织并贯穿织物起到层间约束作用。通过显微镜观察三维机织增强复合材料各个切面(分别沿经纱、纬纱和接结纱),并测量纱线卷曲度、横截面积、组织单元尺寸等关键几何参数。测量结果表明,这种三维机织系统可实现三维正交无卷曲机织增强体的织造。