Study On Triaxial Fabric Weaving And Its Composite Tensile Mechanism

The triaxial woven fabric is interwoven with three sets of yarns in a certain regular pattern to form an in-plane quasi-isotropic fabric.The plain triaxial woven fabric has evenly distributed hexagonal holes.At present,there are few studies on triaxial woven fabrics in China,and the discussion on triaxial fabric weaving technology is rarely seen.In view of such phenomenons,based on some work of the research group,this paper mainly does the following work.(1)On the basis of the triaxial weaving loom developed by the laboratory,in order to solve the problem that the triaxial weaving loom could not achieve continuous weaving,a detachable cover type winding roller were designed and manufactured.The continuous weaving of the triaxial weaving loom was successfully achieved by the design and installation of the winding roller.Based on the detachable cover winding roller,a ratchet pawl device is designed to control the movement of the triaxial woven fabric during the weaving process.According to the different hole sizes of different specifications,the ratchet parameters are designed reasonably and the goal for match of beating and winding is achieved.The successful design and installation of the detachable cover-type winding roller takes into account the fabric tension during the winding process on the basis of continuous weaving of the triaxial fabric.(2)Two sizes of triaxial fabrics were woven using SW yarn and 12 K carbon fiber yarns.12 K carbon fiber flat type(P-12K)triaxial fabric composite,and resin-free SW spread tow of carbon fiber(H-SW)and 12 K carbon fiber(H-12K)were formed in the hexagonal hole of the triaxial fabric.Three kinds of samples of P-12 K,H-12 K and H-SW were prepared for these two kinds ofmaterials and tensile fracture test was carried out.The tensile properties of the three materials were analyzed.(3)Based on the analysis of tensile failure of the materials,the full field strain of SW and12 K carbon fiber triaxial fabric hole composite during tensile process was measured by non-contact method.It is found that the 12 K carbon fiber and SW yarn carbon fiber hole composites have different interweaving state of the three-directional fabric carbon fiber yarn,resulting in the strain of the 12 K carbon fiber hole-type composite material at the interlacing point is higher than the SW yarn carbon fiber hole type composite.Combine the metallography specimen and the failure in tensile process,it is found that twist of the SW yarn carbon fiber hole composites at the interlacing point was decreased.(4)The tensile fracture process of SW yarn,12 K carbon fiber triaxial fabric hole type and12 K carbon fiber plane triaxial fabric composite was analyzed by acoustic emission technology.The difference in the number of AE energies and AE events produced during the stretching of the three types of samples was compared.At the same time,the obtained AE signals were classified by K-means cluster analysis method and corresponded to the failure modes.The tensile fracture process of triaxial fabric composites was analyzed from the internal failure mechanism of triaxial fabric composites.