Study On The Interlayer Shear Performance Of PAN/basalt Fiber Core-spun Yarn Reinforced Composites

Basalt fiber reinforced composites have been widely used in automobile,aviation,shipbuilding and industrial construction because of their advantages of low cost,high mechanical properties and good heat resistance.However,due to the weak interfacial bonding between the basalt fiber and the resin matrix,the overall mechanical properties of basalt fiber reinforced composites are poor.In this thesis,the polyacrylonitrile(PAN)/basalt fiber core-spun yarns were prepared by conjugate electrospinning method with PAN nanofibers coated on the surface of basalt fiber.After that,the unidirectional strip and plain weave fabric were prepared with the basalt fiber and core-spun yarn and the composites were manufactured by laying the fabrics and curing them with resin.The interfacial bonding properties and interlaminar shear properties of the composites were tested and analyzed by fiber pull-put test and short beam shear test.Here,the effects of electrospun nanofibers on the interfacial bonding properties and interlaminar shear properties of basalt fiber reinforced composites were studied.The results show that:(1)Compared with the original basalt fiber reinforced composites,the interfacial shear strength of PAN/basalt fiber core-spun yarn reinforced composites prepared by the optimal electrospinning parameters(moving speed of the core yarn is 0.25 mm/s,rotating speed of the rotary turntable is 200 rpm)is increased by 31.33%.(2)A gradient interlayer structure was formed between the basalt fibers and the resin after the PAN nanofibers were coated on the surface of basalt fibers.This gradient interfacial layer could promote the interfacial adhesion and improve the interfacial bonding performance of the composites.(3)Compared with basalt fiber reinforced unidirectional/plain grain composites,the interlaminar shear strength of PAN/basalt fiber core-spun yarn reinforced unidirectional/plain grain composites is increased by 11.5% and 8.72%,respectively.(4)The reinforcement structure has a very important effect on the interlaminar bonding performance and failure mode of the composites.The fiber reinforcement in the warp and weft directions of plain fabric structure is beneficial to prevent the propagation of interlaminar shear cracks and prolong the final failure time of the material.Therefore,in the process of test loading,plain fabric reinforced composites bear more loads than unidirectional fabric reinforced composites,and the stress situation is more complex.