内含中空纤维型复合材料自修复效率及力学性能

发布时间：2019-03-17 10:28

【摘要】：纤维增强复合材料因其具有较高的比强度、比刚度而越来越多地应用在航空航天,汽车等其他领域。但其基本构造形式大多为层合结构,铺层过程中存在缺少增强纤维等问题。当层合板承受外部载荷时容易发生层间开裂,从而降低结构的整体刚度和强度,甚至损坏层合板,使其应用受到限制。因此通过自修复的方法对裂纹及损伤的部位进行修复,进而延长材料的使用寿命至关重要。将外径为Φ0.9mm的中空玻璃管横置在碳纤维环氧树脂基复合材料层合板的内部,选用环氧树脂为修复剂,固化成型之后切割成三点弯曲标准试件。对部分试件进行准静态压痕实验,之后通过热激励使带修复剂的试件进行自修复,修复后将全部试件进行三点弯曲实验。分析计算实验结果,可知①中空玻璃管在层合板中采用横置的放置方式不会降低层合板本身的力学性能;②准静态压痕实验,损伤程度随加载载荷的增大而增大。当准静态压痕实验加载载荷为1700N时,试件的抗弯曲性能最大降低37%;③层合板中的中空玻璃管经准静态压痕实验的破坏,管中的修复剂能够快速流到层合板的受损部位,修复裂纹,粘合裂纹,起到修复的目的。受损试件的弯曲强度最大能恢复到原始强度的109%。参照复合材料层合板中"z-pin"的放置方式,将外径为Φ0.9mm的中空玻璃管沿厚度方向植入到铺设好的预浸料中,选用ENB为修复剂,构建自修复系统。预浸料层合板固化成型之后加工成双悬臂梁试件和三点弯曲试件。通过压力破坏实验、三点弯曲实验以及双悬臂梁实验的对比分析,可知①在压力破坏实验中,8KN的压力使试件的抗弯曲性能最大降低11.91%;②ENB和Grubbs催化剂组成的修复系统能够修复层合板中的任一层裂纹,粘合裂纹,使受损试件的弯曲强度恢复到原强度的96.63%;③双悬臂梁实验中,纵置的中空玻璃管能起到对层合板增韧的作用,且增韧效果随中空玻璃管分布密度的增大而增强,最大断裂载荷值增大33.26%。选用环氧树脂为修复剂,参照复合材料层合板中"z-pin"的放置方式,采用上述实验方法和实验过程,进行准静态压痕实验和三点弯曲实验。分析计算实验结果,可知①中空玻璃管在层合板中采用纵置的放置方式能够提高层合板的抗弯曲性能,在同一工况下试件的抗弯曲性能被提高了 32.24%;②在准静态压痕实验中,损伤程度随加载载荷的增大而增大。当准静态压痕实验加载载荷为5KN时,三种类型试件的抗弯曲性能最大降低57.83%;③层合板中环氧树脂修复系统能够修复层合板中的任一层裂纹,粘合裂纹,其修复效率随中空玻璃管分布密度的增大而增加,受损试件的弯曲强度最大能恢复到原始强度的66.85%。
[Abstract]:Fiber reinforced composites are more and more used in aerospace, automobile and other fields because of their high specific strength and specific stiffness. However, most of its basic structural forms are laminate structure, and there are some problems in the process of lamination, such as the lack of reinforced fiber and so on. When the laminate is subjected to external load, the interlaminar cracking occurs easily, so as to reduce the overall stiffness and strength of the structure, and even damage the laminated plate, so that its application is limited. Therefore, it is very important to repair the crack and damage site by self-repairing method, so as to prolong the service life of the material. The hollow glass tube with the outer diameter 桅 0.9mm was placed in the interior of the carbon fiber epoxy resin matrix composite laminate. The epoxy resin was selected as the repairing agent. After curing, the standard specimen was cut into three-point bending. Some specimens were subjected to quasi-static indentation test, then self-repair was carried out by thermal excitation, and three-point bending test was carried out on all specimens after repair. The experimental results show that (1) the transverse placement of hollow glass tubes in laminates will not reduce the mechanical properties of the laminate itself; (2) in quasi-static indentation experiment, the damage degree will increase with the increase of loading load. When the load of quasi-static indentation experiment is 1 700 N, the bending resistance of the specimen decreases by 37%. The hollow glass pipe in the laminate is destroyed by quasi-static indentation experiment. The repairing agent in the pipe can quickly flow to the damaged part of the laminate, repair the crack, glue the crack, and play the purpose of repairing. The maximum flexural strength of the damaged specimen can be recovered to 109% of the original strength. Referring to the placement mode of "z-pin" in composite laminate, the hollow glass pipe with the outer diameter 桅 0.9mm was implanted into the prepreg material along the thickness direction, and ENB was used as the repairing agent to construct the self-repairing system. After the prepreg laminate is solidified, it is machined into double cantilever beam and three-point bending specimen. Through the comparative analysis of pressure failure test, three-point bending test and double cantilever beam experiment, it is known that 1 in the pressure failure experiment, the bending resistance of the specimen is reduced by 11.91% maximum by the pressure of 8KN; The repair system composed of 2ENB and Grubbs catalysts can repair any layer crack in the laminate, and the bending strength of the damaged specimen can be restored to 96.63% of the original strength. 3 in the experiment of double cantilever beam, the vertical hollow glass tube can toughen the laminate, and the toughening effect increases with the increase of the distribution density of the hollow glass tube, and the maximum fracture load value increases by 33.26%. The quasi-static indentation experiment and three-point bending experiment were carried out by using epoxy resin as repairing agent and referring to the placement mode of "z-pin" in composite laminate, using the above-mentioned experimental methods and experimental process to carry out the quasi-static indentation experiment and three-point bending experiment. The experimental results show that 1the vertical placement of hollow glass tube in laminates can improve the bending resistance of laminated plates, and the bending resistance of specimens is increased by 32.24% under the same working condition; 2 in quasi-static indentation experiment, the damage degree increases with the increase of loading load. When the load of quasi-static indentation experiment is 5KN, the bending resistance of the three types of specimens decreases by 57.83%. The epoxy resin repair system in the laminate can repair any layer crack in the laminate, and the repair efficiency increases with the increase of the distribution density of the hollow glass tube, and the repair efficiency increases with the increase of the distribution density of the hollow glass tube. The maximum flexural strength of the damaged specimen can be recovered to 66.85% of the original strength.
【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】：TB332

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