改性UHMWPE纤维纬平针织复合材料的力学性能研究

发布时间：2018-03-28 19:28

本文选题：纬编针织复合材料　切入点：UHMWPE纤维　出处：《天津工业大学》2017年硕士论文

【摘要】：纬编针织结构作为复合材料的增强体结构,能够赋予复合材料良好的成形性、能量吸收性好等优点,已经广泛应用于防护、建筑等领域。UHMWPE纤维作为第三代高性能纤维,是唯一一种能够浮在水面上的纤维,以模量高、耐气候性和耐化学腐蚀性的特点,备受人们的青睐。本课题对改性UHMWPE纤维纬平针织复合材料的制备工艺和力学性能进行了研究,并采用ABAQUS软件对复合材料的冲击性能进行了模拟研究,希望能够为纬编针织复合材料的研究提供一定的理论参考。为实现UHMWPE纱线在电脑横机上的顺利织造,首先将原料UHMWPE复合长丝进行加捻和防静电处理,然后在织机上通过反复调整织造工艺参数,成功织造出了结构均匀良好的纬平针织物。复合材料的树脂基体选用GCC-135环氧树脂,制备工艺选用能够实现树脂对纤维良好浸润的VARTM成型工艺和能够通过控制复合材料厚度来间接控制复合材料纤维体积含量的模压成型工艺相结合的方式,成功制备出8层、12层和16层纬平针织复合材料。对三种不同层数纬平针织复合材料的力学性能进行测试,通过对强力-位移曲线、应力-应变曲线等分析,得出16层纬平针织复合材料的总体力学性能最好,12层次之,8层最差;但由于复合材料层间破坏的不同时性,试样的拉伸强度、压缩强度随着层数的增加而减小。当复合材料发生应变较小时,树脂基体产生破坏,增强结构只是发生了变形,未产生破坏。用扫描电镜对试样的微观损伤形貌进行观察,发现在裸露和断口处纤维表面包覆有树脂,并未出现纤维抽拔。这表明经改性处理后,纱线和树脂间的粘结作用增强。针对Pierce线圈模型和B样条线圈模型的特点,参照纬平针织物实际线圈在三维空间中的几何形态,提供了一种采用特殊型值点建立纬平针织物模型的新方法。之后采用有限元分析软件ABAQUS对复合材料的低速冲击性能进行了模拟研究。将模拟结果与实验结果进行比较,复合材料的冲击损伤形式和试样吸收能量值与试验结果比较接近,为进一步复合材料的力学性能研究做了铺垫。
[Abstract]:As a reinforced structure of composite material, weft knitted structure can give the composite good formability, good energy absorption and so on. It has been widely used in protection, construction and other fields. UHMWPE fiber as the third generation of high performance fiber, It is the only fiber that can float on the surface of the water. It is very popular because of its high modulus, weather resistance and chemical corrosion resistance. The preparation technology and mechanical properties of modified UHMWPE fiber weft knitting composites are studied in this paper. The impact properties of the composites are simulated by using ABAQUS software. It is hoped that it can provide a theoretical reference for the study of weft knitted composites, and to realize the smooth weaving of UHMWPE yarns on a computerized flat knitting machine. After twisting and antistatic treatment of the raw material UHMWPE composite filament, the weft plain knitted fabric with good structure and good structure was successfully woven on the loom by adjusting the weaving process parameters repeatedly. The resin matrix of the composite was made of GCC-135 epoxy resin. The preparation process is composed of VARTM forming process which can achieve good fiber wetting of resin and moulding molding process which can indirectly control fiber volume content by controlling the thickness of composite material. Eight layers of 12 and 16 layers of weft knitting composites were successfully prepared. The mechanical properties of three different layers of weft plain knitted composites were tested. The strength displacement curves, stress-strain curves and so on were analyzed. It is concluded that the overall mechanical properties of 16 layers of weft knitting composites are the best and that of 12 layers are the worst, but the tensile strength of the specimens is due to the different interlaminar failure of the composites. The compressive strength decreases with the increase of the number of layers. When the strain of the composite is small, the resin matrix is destroyed, the reinforced structure is only deformed, but not destroyed. The microstructure of the specimen is observed by scanning electron microscope (SEM). It is found that there is resin coated on the surface of the fiber at the bare and fracture surfaces, and no fiber pull-out occurs. This indicates that the adhesion between the yarn and the resin is enhanced after modification. According to the characteristics of the Pierce coil model and B-spline coil model, Referring to the geometry of the actual coils of the weft knitted fabric in three dimensional space, A new method for modeling weft knitted fabric with special value points is presented. The low speed impact properties of composites are simulated by finite element analysis software ABAQUS. The simulation results are compared with the experimental results. The impact damage form and the absorption energy value of the composite materials are close to the experimental results, which provides a basis for the further study of the mechanical properties of the composites.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33

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