泡沫填充密度对纺织增强材料平压性能影响

探讨泡沫填充密度对纺织增强复合板材平压性能的影响。以涤纶长丝为原料织制了间隔机织物,用聚氨酯泡沫填充织物的间隔,用环氧树脂对板材表面进行涂层复合,制备了三明治型复合板材。通过改变聚氨酯泡沫材料的填充量,设计加工了7种填充密度的板材,并对其平压性能进行了测试。结果表明:随着填充密度的增加,平压强度呈现整体上升趋势,增加到一个极限密度后平压强度开始下降;泡沫填充密度与板材平压强度呈抛物线关系,泡沫填充密度为0.134 5g/cm3时,板材获得最大平压强度。认为:通过测试分析可以使纺织增强复合板材获得较佳的力学性能。     

废旧塑料原料与竹加工剩余物制作竹塑复合板的试验研究

以废旧聚丙烯塑料颗粒和竹材加工剩余物为原料,通过共混粉碎、平压复合技术制成一种复合板材。探讨了密度、物料配比、热压工艺等条件对复合板产品性能的影响,获得优化的工艺参数。试验结果表明:所压制的复合板性能良好,复合板在制造和使用过程中无甲醛等有害气体释放,在长期使用报废后仍可再生利用。     

废旧塑料原料与竹加工剩余物制作竹塑复合板的试验研究

以废旧聚丙烯塑料颗粒和竹材加工剩余物为原料，通过共混粉碎、平压复合技术制成一种复合板材。探讨了密度、物料配比、热压工艺等条件对复合板产品性能的影响，获得优化的工艺参数。试验结果表明：所压制的复合板性能良好，复合板在制造和使用过程中无甲醛等有害气体释放，在长期使用报废后仍可再生利用。     

UHMWPE短纤维纱增强复合板性能研究

选用以1.21dtex、51mm的UHMWPE短纤维制成的2/295.5dtex纱,编制成单向、双向、平纹、纱罗、互绞五种增强层用于网格板,选用热塑性环氧树脂,采用涂刷方法制成厚度6 mm平板,取得试验样条,在WOTEI-20微机控制万能材料试验机上测取拉伸和弯曲性能。结果表明:复合板材的拉伸、弯曲性能均有增强,弯曲性能增强更为显著;编入纱线的X向的拉伸、弯曲增强明显较Y向好,但稳定性较差;双向有编织的板材,拉伸、弯曲增强更稳定。     

间隔机织物结构对复合板材平压性能的影响

探讨间隔机织物结构对复合板材平压性能的影响。分别设计织造了不同接结纱密度、接结纱高度和面层组织密度的间隔机织物,并制备了三明治型复合板材。对不同结构复合板材进行平压性能测试。结果表明:复合板材的平压强度随着接结纱密度的增加先增大后减小,存在最佳接结纱密度;复合板材的平压强度随着间隔机织物接结纱高度的增加而减小,随面层组织密度的增大稍有下降。认为:间隔机织物的接结纱密度控制在1.2根/cm2左右,接结纱树脂柱和泡沫填充材料可以协同作用,共同承压,此时板材的抗压能力较好。     

间隔织物面层组织对其增强板材性能的影响

设计织造平纹、方平、2/2斜纹和1/3斜纹4种不同面层组织的间隔织物,并在间隔织物的空间结构中填充聚氨酯泡沫,再用环氧树脂对其表面进行复合,加工制成机织间隔织物复合材料板材.对加工出来的4种间隔织物的复合板材进行压缩和弯曲试验,探讨4种不同的面层组织对间隔织物复合材料板材性能的影响.     

制备工艺对黄麻/聚丙烯针织复合材料性能的影响

 本文讨论了不同工艺黄麻横机针织物增强聚丙烯复合材料的制备工艺对其力学性能的影响。首先利用针织的方法在横机上分别织造黄麻1+1罗纹、畦编、半畦编织物作为复合材料的增强体,分别以3层和5层进行同向铺层、不同质量配比与聚丙烯（PP）纤维均匀混合后通过热压工艺制成复合材料。对所制备的复合材料板材拉伸及弯曲性能进行测试与分析。研究结果表明：在复合织物均为1+1罗纹时,其复合板材性能以3层1+1罗纹6/4的配比为最佳;相同配比,相同层数情况下,畦编组织板材性能则最优;对于相同配比1+1罗纹板材3层性能优于5层。     

接结纱细度对机织间隔织物复合板材平压性能的影响

以高强低伸工业涤纶长丝为原料织制机织间隔织物,用聚氨酯泡沫填充织物的间隔,用环氧树脂对板材表面进行涂层复合,制成机织间隔织物复合板材。由于间隔织物复合板材的压缩性能主要取决于其夹芯结构,接结纱细度的不同会影响板材的平压性能,通过改变接结纱的细度,设计加工了5种接结纱细度的板材,并对其平压性能进行了测试分析。通过分析载荷变形曲线,得知板材的压缩历经契合、弹性、屈服、压实4个过程;同时,随着接结纱细度的增加,板材的契合所需变形量、平压强度、弹性模量等各项性能均明显增加,且增加幅度越来越大。     

预定型弯曲柱纱三维机织间隔复合材料的压缩性能

为探究柱纱弯曲程度对三维机织间隔复合材料(3DWSC)压缩稳定性的影响,采用手糊成型工艺将环氧树脂与三维机织间隔织物进行复合,并在其固化成型前对材料进行压缩预定型,制备了4种不同厚度即4种柱纱弯曲程度的三维机织间隔复合材料。探究了柱纱弯曲程度对3DWSC平压性能、平压破坏模式及疲劳性能的影响。结果表明,随着柱纱弯曲程度的增大,3DWSC的平压强度先降低后提升,柱纱的破坏模式由脆性断裂和失稳逐渐转变为屈服破坏,3DWSC的疲劳性能下降。     

热固型环氧树脂对UHMWPE短纤纱织物的复合渗透研究

为研究热固型树脂对UHMWPE短纤维纱机织物增强材料的渗透性能,选用1.21dtex、38 mm UHMWPE短纤维纺成的纱线,制成2种不同规格的平纹织物,用质量分数35%H2O2氧化、H2O2氧化+K550偶联剂接合、电晕等加以改性,采用真空渗透制成环氧树脂/UHMWPE复合板,测算织物改性前后的面密度Ps、复合板中环氧树脂的体积占比εV和质量占比εM。结果表明:H2O2化学改性可以提高环氧树脂对UHMWPE织物的体积和质量渗透率,追加偶联剂接合改性更有利于树脂的体积渗透;电晕物理改性无助于树脂渗透;以薄型UHMWPE织物多层叠合,树脂的渗透效果更好。     

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.     

蜂巢棉织物力学性能的测试与分析

为使蜂巢组织类织物在增强复合材料中得到更合理的应用,采用相同的原料和经纬密度织制不同蜂巢类组织织物,并对织物的拉伸强度、撕裂强度和顶破强度进行测试,分析不同蜂巢组织对其织物力学性能的影响。结果表明:在织物原料和经纬密度相同的情况下,不同蜂巢组织的织物其力学性能有明显的不同;纱线的交织次数越多,蜂窝越小,织物的断裂强力越大;而织物断裂伸长率、撕裂强力和顶破强力随着蜂窝尺寸的变小,先增加后减少。     

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。     

纬纱接结的三维正交机织物结构

为了研究正交机织物的实际结构,采用玻璃纤维在剑杆织机上织制了纬纱接结的6层经纱5层纬纱的正交机织物,然后利用VARI工艺与聚酯树脂复合,制成了复合材料板材试样,并在显微镜下观测纱线的形状。研究发现:三维正交机织物的经、纬纱基本呈直线状态,接结纬纱是曲线与直线组合的形状,且形状与在织物中的位置有关,越靠近织物中央,接结纬纱的直线部分越短;接结纬纱使其限定的经纱产生聚集现象,在复合材料中产生贫富树脂区,接结纬纱形状的变化也使织物的结构不均匀。对织造过程的分析表明,造成接结纬纱形状变化的原因是织物形成过程中接结纬纱的滑动,从织物边部到中央,接结纬纱的滑动阻力逐渐增大,接结纬纱的张力也逐渐增大。     

玄武岩纤维机织针织复合结构增强复合材料的拉伸性能

根据新型机织针织复合织物的结构特点,分别选用不同线密度的高强高模玄武岩纤维作为经纱、纬纱和针织纱编织织物,以其作为增强体,采用VARTM工艺制作玄武岩纤维/乙烯复合材料.为提供这种新型织物增强复合材料的应用依据,测试了复合材料的横向、纵向和斜向拉伸性能,并对各个方向的拉伸应力与应变特征曲线及其拉伸断裂形态进行分析,对比...     

Warp and weft directional tensile properties of multistitched biaxial woven E-glass/polyester composites

The objective of this research work was to understand the warp and weft directional tensile properties of the two-dimensional multistitched multilayer E-glass/polyester woven composites. The warp and weft directional specific tensile strength and modulus of unstitched structure were higher than those of multistitched structures as stitching caused minor warp and weft yarn filament breakages. Contrarily, the specific tensile strains of unstitched structure were slightly lower than those of all multistitched structures. The stitching yarn type, the number of stitching directions, and the stitching density generally influenced the warp and weft directional tensile properties of multistitched E-glass/polyester woven composites. The failure of warp and weft directional multistitched woven E-glass/polyester composite structures was matrix breakages, and partial and complete yarn breakages in their surfaces. They had a local delamination in their cross-sections and the delamination did not propagate to the large areas due to multidirectional stitching. Also, the failure was confined at a narrow area and resulted in the catastrophic fiber breakages. The warp and weft directional specific damaged areas of multistitched structures, in particular four-directional stitching, were significantly lower than those of the unstitched structures. This indicated that the multistitching made the structures better damage-tolerance materials.     

A novel method to investigate tensile properties of woven fabrics in all-direction

In this research, we propose a new method and instrument to measure load-extension curve of the fabric samples under all-directional extension. Using this method, fabric sample is loaded under extension in the warp, weft, and all other directions in between. Using this new method, we introduced a comprehensive tensile modulus which is affected by the fabric structures and densities. For this purpose different structures i.e. plain, Twill 2/2, Twill 1/3, and Twill 1/7 were produced with different densities. Then these samples were tested under the new method. Our results are then compared to those one would obtain under uniaxial tests, by performing independent uniaxial tests. It is shown that under all-directional test lowering the weft density decreases the tensile comprehensive modulus. Furthermore, a reduction in the floating yarns in the fabric structure decreases the tensile comprehensive modulus. It was found that among the samples tested here, plain fabric and Twill 1/7, respectively, possess the maximum and minimum comprehensive modulus. A similar trend was also observed through independent uniaxial extension, in warp or weft direction, test.     

Mechanical Properties of Composite Panels Reinforced with Integrally Woven 3-D Fabrics

An investigation is reported in which six three-dimensional cellular fabrics were designed and woven. They consisted of two facings connected by an integrally woven sinusoidal core. In lateral compression, the ratio of the cell-repeat distance to the fabric thickness determines the resistance of the fabrics to buckling. Composite panels were fabricated by impregnating the fabrics with resin. Formulae developed allow the cross-sectional area and second moments of area of the panels to be calculated. Tensile tests were performed on the panel facings and whole structures to measure the Young's moduli and strengths in the longitudinal (weft) and transverse (warp) directions. Flexural tests were made to measure the beam flexural rigidities. The structural analysis of the beam sections together with the tensile properties of the beams enables flexural properties to be accurately predicted. The properties of the 3-D beams in flexure are comparable to those of other engineering materials, but the fabric-based, cellular composites will have advantages as components in composite structures.     

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。