Study On The Unidirectional Inter-layer Cf/Gf Hybrid Composites For Wind Turbine Blades

Carbon fiber composite which is a kind of matieral with high stiffness and light wight could be used in wind blade to solve the problem of lack of stiffness in longer wind blade. But carbon fiber is too expensive. If we use carbon fiber/glass fiber hybrid composite, we can solve the problem of lack of stiffness in longer wind blade and get a lower cast.In this subject, I make composite with unidirectional carbon/glass fabric inter-layer hybrid fabric with three hybrid ratio and epoxy resin. The effect of hybrid ratio and dispersion on the mechanical property include tensile property, compressive property, flexural property, shearing property between the inter ply is investigated. The destroy model is analyzed. And I also made some study about the permeability and thickness of the hybrid fabric and glass fabric.The study about tensile property show that: The tensile strength of the three hybrid structures is lower than the glass composite.And there is little difference among the three hybrid structures in tensile strength. The glass composite destroy by the way of exploding. The three hybrid structures destroy mainly by the way of delamination. In the same time, a little of the carbon fiber is broken. The tensile modulus of the hybrid is increased by 18.12%,28.58%,30.99% with 3 different hybrid ratio, respectively.The study about axial compression property show that: The carbon fibers are introduced into the warp knitted glass fiber fabric, which improves the strength and module of the axial compression. The strength of axial compression of the hybrid was increased by 22.72%、26.95%、11.43% with 3 different hybrid ratio, respectively. Different hybrid ratio will give out different damge mode. The moduli of axial compression increased with the increasing content percentage of carbon fiber. The strength of axial compression increased with the increasing of dispersion. And the modulus of axial compression is not related with the method of lay-up under the same hybrid ratio of carbon fiber and glass fiber. The destroy model of axial compression of the four structures all show the breakage of the carbon fiber and interlaminar delamination at the breakage location. The strength and modulus of axial compression of the unidirectional carbon/glass inter-layer hybrid fabric composite is bigger than those of the hybrid composite which by lay-up using carbon fabric and glass fabric.The study about flexural property show that: The carbon fibers are introduced into the warp knitted glass fiber fabric, which improves the flexural strength and moduli. The flexural strength with different hybrid ratio is similar and the moduli increases with the increasing content percentage of carbon fiber. The flexural strength is not related with the method of lay-up under the same hybrid ratio of carbon fiber and glass fiber. And the flexural modulus increased with the increasing of dispersion The destroy method of flexural of the four structures all show the breakage at the compressed side. The flexural strength of the four structures have little difference.The study about shearing property between the inter ply show that: There is no influence of the hybrid ratio of carbon fiber and glass fiber on the shearing strength between the inter ply. And the shearing strength between the inter ply of the hybrid structure and pure glass structure is similar. The destroy occurred at the interface of glass/glass. The shearing strength between the inter ply is not related with the method of lay-up under the same hybrid ratio of carbon fiber and glass fiber.The study about characteristic thickness of one ply show that: The characteristic thickness of one ply increased with the increasing carbon fiber content. The characteristic thickness of one ply increased 0.04 mm when the caarbon fiber add 50 g.The study about the permeability of the fabric show that: The permeability along the X direction decreased as the carbon fiber content increase. The permeability along the Y and Z direction of the hybrid fabric have little difference with the glass fabric.