机织三维角联锁结构织物复合板材的制备与力学性能研究

利用真空辅助成型工艺,将机织三维角联锁结构织物与树脂结合制备机织三维角联锁结构织物复合板材.测试不同单位体积纤维含量和不同织物层数的机织三维角联锁结构织物复合板材的力学性能,并与纤维随机分布的复合板材进行比较.研究表明:机织三维角联锁结构织物复合板材的力学性能高于相同单位体积纤维含量的纤维随机分布的复合板材,且当单位体积纤维含量在55.37％时,机织三维角联锁结构织物复合板材的力学性能最佳;对于单位体积纤维含量一定的机织三维角联锁结构织物复合板材,随着织物层数的增加,其力学性能提高.     

基于废弃聚苯硫醚滤料的多层吸声材料制备及其性能

为解决废旧聚苯硫醚(PPS)滤袋难处理的问题,将其回收进行碱洗处理,再利用热风黏合成形加工方法将碱洗处理的滤袋与不同厚度规格的聚氨酯(PU)膜相结合制备多层吸声复合材料。借助扫描电子显微镜、垂直法阻燃性能测试仪、电子织物强力机、噪声振动测试系统对PPS+PU+PPS与PPS+PU+PPS+PU+PPS 这2种结构形貌特征、阻燃性能、力学性能、吸声隔声性能进行表征。结果表明:碱洗处理的滤袋表面依然残留少量粉尘颗粒,但并未出现纤维破损断裂的现象,纤维间孔隙较多,复合材料纤维间的孔隙减少,内部变得致密;处理后的复合材料,阻燃性能与单层PPS滤料相比,依旧保持较好,在同种结构中,其力学性能均与PU膜厚度呈现正相关;2种结构中,吸声系数呈现出相同的变化趋势,并且大小与膜厚呈现负相关,高频阶段最大可达0.27,传递损失程度与膜厚呈现负相关,PPS+PU+PPS+PU+PPS结构在高频阶段最高可达41 dB。     

三层机织间隔织物的设计与织造

间隔织物是纤维复合材料的增强体,决定着材料的最终使用效果,但是三层机织间隔织物的研究目前尚属空白。设计并成功制备出三层机织间隔织物。首先用画图软件模拟出三层间隔织物的纱线走向图,然后根据经向剖面图画出上机图;选用玄武岩纤维/丙纶包缠纱作为经纬纱,芳纶作为接结纱,表层、中层、里层都选用平纹组织;采用双经轴送经、钢条定距法织造。总结了影响三层机织间隔织物织造过程的因素,形成了具体织造技术,丰富了三维机织物组织结构库。     

叠经式多层间隔结构整体机织预制体的实现

研究叠经式多层间隔结构整体机织预制体的实现方法.通过分析现有机织间隔结构复合材料预制体的结构缺陷,提出一种新型的叠经式多层间隔结构,并进行了试织.结果表明:与现有纺织间隔结构复合材料预制体相比,叠经结构增加了子层经纱和连接经纱密度,还有利于采用扁平状纤维束及织物带织造,改善了预制体中纤维的平直度,提高了材料拉伸、压缩、剪切结构强度和模量,增加了材料的总体高度及抗弯性能.     

超高分子量聚乙烯织物/聚脲柔性复合材料的抗破片侵彻机制

为研究平纹机织叠层和三维角联锁增强聚脲柔性复合材料的抗侵彻性能，以15 mm角联锁整体织物及叠层平纹织物(单层厚度0.39 mm, 40层)为研究对象，通过表面喷涂聚脲制备2种不同织物结构的超高分子量聚乙烯(UHMWPE)织物/聚脲柔性复合材料；采用1.1 g柱状楔形破碎片，开展了弹道侵彻实验，并获取了弹道极限速度和比吸能；在此基础上，借助超景深显微镜及计算机断层扫描仪，观察侵彻后UHMWPE织物/聚脲柔性复合材料的表面及内部损伤形貌，分析抗破片侵彻机制。研究结果表明：UHMWPE织物/聚脲柔性复合材料抗破片侵彻性能具有明显的织物结构效应；相较于同厚度的叠层平纹织物增强聚脲柔性复合材料，角联锁织物增强聚脲柔性复合材料的弹道极限速度提升了4.9%;对于未被穿透的UHMWPE织物/聚脲柔性复合材料，其被侵彻过程主要包括聚脲对破片的包裹、剪切冲塞和纤维拉伸断裂破坏；叠层平纹织物的主要失效模式为剪切冲塞、分层失效，角联锁织物主要为纤维拉伸变形、拉伸断裂破坏。     

新型三维纺织复合材料预制件织造方法的探讨

简要叙述了三维机织与编织的织造方法,纯三维机织织物强度低,纤维体积含量较小;而纯编织织物虽然轴向力学性能优良,但层间剪切强度及横向的力学性能较差。为克服这两者的缺点而探索一种新的织造方法,即机织与编织结合的方法,对这种新方法做了初步的实验研究,以期推动纺织复合材料这门学科不断向前发展。     

角联锁三维机织物在多综眼织机上的织造设计

针对三维机织物在厚度方向拓展受到限制的现状,提出两种关于把三维机织物织厚的设计方案。通过以层层正交角联锁织物为例,探究将厚度推广为N层的织物在多综眼织机上的织造方法,设计上机工艺(包括穿综图、纹板图及选纬图)。通过实际上机实验,成功使用两种方案织出层层正交角联锁织物。结果表明,两种设计方案都可用于织造不同厚度的角联锁三维机织物,同时两种方案都具备各自的织造特性。     

喷射口角联锁织物复合材料横向耐冲击性能

利用半自动小样织机织制不同组织结构的喷射口角联锁织物,再通过真空辅助树脂转移模型技术制成喷射口角联锁织物复合材料,对比它们的横向耐冲击性能。结果表明:对于不同结构、相同循环喷射口角联锁织物复合材料而言,可承受的冲击载荷方面,六层实口三循环喷射口角联锁织物复合材料最大、四层实口三循环喷射口角联锁织物复合材料优于四层空口三循环喷射口角联锁织物复合材料,能量吸收方面,六层实口三循环喷射口角联锁织物复合材料的能量吸收最大、四层空口三循环喷射口角联锁织物复合材料优于四层实口三循环喷射口角联锁织物复合材料;对于相同结构、不同循环喷射口角联锁织物复合材料而言,四层实口三循环喷射口角联锁织物复合材料可承受的冲击载荷及能量吸收都优于四层实口二循环喷射口角联锁织物复合材料。     

多层多向机织复合材料细观结构建模及其性能

为分析多层多向机织复合材料的细观结构,基于多层多向机织工艺及不同于传统机织结构的纱线空间运动规律,推导了工艺参数与结构参数之间的关系,建立了细观结构分析模型;为研究多层多向机织复合材料的拉伸性能和失效机制,采用多层多向机织工艺、树脂传递模塑复合工艺,以碳纤维和环氧树脂为原材料制备了2种不同结构的多层多向机织复合材料,采用万能试验机和非接触全场应变仪对材料进行了0°和90°方向的准静态拉伸性能测试,并与正交三向机织复合材料进行了对比分析。结果表明:斜向纱的存在对多层多向机织复合材料的拉伸破坏模式和断口形貌有较大影响,斜向纱一定程度上阻碍了裂纹和应变沿承载方向扩展,0°方向拉伸试样断口处经纱层内经纱全部断裂,90°方向拉伸试样断口处纬纱层内纬纱全部断裂,2个方向的拉伸试样斜向纱层中均存在部分斜向纱纤维未断裂,拉伸试样非完全断裂。     

多层圆角矩形三维机织物的设计与织造原理

探讨多层圆角矩形三维机织物的设计与织造原理。通过多层三维正交角联锁组织织物结构的设计与分析得出了织物层数与经纬纱循环数之间的规律,在此基础上研究了多层圆角矩形织物的设计结构与织造原理。为使圆角矩形织物的结构均匀,使不同长度的短纬分布在长纬之间,在织造时对经纱分组控制织造。夹持式全自动卷取装置不仅可以控制圆角矩形织物的卷取过程,而且通过夹头控制织物每次转弯的形状和角度。认为:该方法操作简单、无断纱,织造效率高,适用性广,易于实施。     

不同层数和穿筘方式的正交织物复合材料隔声性能研究

以玻璃纤维为原料,在SGA598半自动小样机上织造正交织物,使用真空辅助成型法制作正交织物复合材料,探讨不同层数、不同穿筘方式的正交织物复合材料的隔声性能,结果发现:层数越多的正交织物复合材料,纤维体积分数增大,其隔声性能越好;层数相同时,4/2穿筘方式的正交织物复合材料的隔声性能要优于2/2穿筘方式的正交织物复合材料。     

角联锁织物的拉伸性能分析

介绍了角联锁织物的结构特点,采用小样箭杆织机织造了层数为2层、3层到9层的角联锁织物共8块,探讨了角联锁织物的拉伸性能与其结构层数之间的关系。结果表明,随着角联锁织物层数的增加,其断裂伸长率也会随之增加,但到一定层数时,断裂伸长率反而出现降低趋势。     

立体织物在二氧化硅基复合材料方面的应用前景

摘要：连续纤维及其织物增韧的二氧化硅基（SiO2）复合材料具有强度高、韧性好、密度低等特点,是用于天线罩的理想材料。本文从不同增韧方式的成型工艺方法、增韧特点出发,综合评价了用于天线罩的颗粒增韧、晶须增韧和连续纤维增韧二氧化硅基复合材料的研究现状,提出适合于增韧二氧化硅基复合材料的立体织物纤维束结构,其中典型的纤维束交织结构包括2.5D机织、正交三向、三维编织及其衍生结构。最后,结合未来导弹天线罩材料的发展趋势,指出了立体织物在二氧化硅基复合材料方面的广泛应用前景和研究重点。     

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.     

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.     

三维机织角联锁SiCf/SiC复合材料弯曲性能及损伤机制

为解决陶瓷基复合材料在服役环境中由于弯曲而导致失效的问题,从理论上分析了经向和纬向弯曲过程中复合材料弯曲受力与内部纤维之间的相互作用机制。以SiC_f/SiC复合材料为例,利用微计算机断层扫描技术获得其内部纤维结构和孔隙等三维图像;并在此基础上,分别对三维机织角联锁SiC_f/SiC复合材料经向和纬向进行弯曲性能测试,从细观、微观尺度分析弯曲损伤机制。结果表明:三维机织角联锁SiC_f/SiC复合材料的纬向和经向性能明显不同,且纬向试样的弯曲强度大于经向试样;SiC_f/SiC复合材料的弯曲损伤模式复杂,经向试样裂纹主要沿着经纱与纬纱接触点扩展,而纬向试样裂纹主要在纬纱束之间产生,并最终导致弯曲破坏。     

组合式3D机织物复合材料的拉伸性能

采用正交和角联锁结构进行组合设计,并使用玻璃纤维试织了2种不同结构的组合式3D立体机织物,经与树脂复合制成增强复合材料,对其拉伸性能进行了测试。结果表明,组合式3D机织物增强复合材料具有接近正交3D机织物增强复合材料的弹性模量和抗拉强度。     

Large-scale finite element analysis of a 3D angle-interlock woven composite undergoing low-cyclic three-point bending fatigue

This paper reports the large-scale finite element analysis (FEA) of a 3D angle-interlock layer-to-layer woven composite material undergoing low-cyclic three-point bending fatigue at microstructure level. A microstructure geometrical model of the 3D woven composite material was established to model the real structure of the woven composite. The fatigue behaviors of the 3D woven composite undergoing three-point bending with sinusoidal wave-form were investigated from experimental and FEA approaches. Based on displacement-controlled bending and inelastic hysteresis energy fatigue damage criterion, the interior deformation, energy absorption, and stress distribution characteristics during the fatigue process were analyzed. The different failure mechanisms and damage patterns of yarns and resin were discussed. The influence of the 3D woven structure on the fatigue behaviors was discussed. The fatigue damage morphologies and stiffness degradation were obtained to compare with the experimental results. The results show that the most of energy was absorbed by warp yarns. Stress concentration was emerged on the inclined part of warp yarns and the interface between yarns and resin. The damage morphologies from experimental and FEA results are in good agreement. The stiffness degradation curves also show the same tendency.     

Finite element analyses of stress distributions of three-dimensional angle-interlock woven composite subjected to three-point bending cyclic loading

This paper presents the finite element simulation of stress distribution features of 3D layer-to-layer angle-interlock woven composite undergoing three-point bending cyclic loading. With the finite element analysis model, a microstructure shell element model of the woven composite at yarn level was established to calculate the fatigue behaviors and stress distribution during cyclic loading. The stress distributions in the warp, weft yarns, and the resin regions have been calculated to show the stress difference in the woven composite. It has been observed that the warp yarns share the most part of the stress or loading, i.e. the strength warp yarn is more important than that of the weft yarn for the fatigue design. In addition, the stress distributions at the locations where the weft yarns crossover the warp yarns have been investigated. The stress degradations of the top and bottom surface of the woven composite panels were also compared with those in experimental and good agreement was found. With the stress distribution in the woven composite, the method of improving the fatigue damage tolerance was expected to be developed.