Study On The Effects Of Resin Matrix Modulus On Compressive Performance Of Carbon Fiber Reinforced Composites

In this article, the modulus of epoxy resin matrix have been changed by changing the crosslinking structure of resin and the content of thermoplastic components. The epoxy resin matrix were applied to make T800 carbon fiber composite materials and studied the effects and mechanism of epoxy resin matrix modulus on compressive performance of carbon fiber reinforced composites.The two different schemes to change the modulus of epoxy matrix are introduced bellow. First one was to select two kind of epoxy resin with different functionality and change the ratio of the epoxies. Second scheme was to changing the content of thermoplastic components in the epoxy matrix. This article has chosen these two schemes and set a series of resin formula. The resin casting body was cured under the condition of proper curing process and the mechanical properties was studied particularly tensile properties.In the first scheme, the example of EP0 has the lowest modulus 3.09 GPa, as the content of the trifunctional epoxy resin increased, the modulus of the resin rose to the highest 4.65 GPa. The longitudinal compressive strength of carbon fiber composites also increased from 1266 MPa to 1466 MPa with the content of S500 M increasing.The study on the resin and carbon fiber made by the first scheme showed that, with the content of the trifunctional epoxy resin increasing, the crosslinking density of resin matrix increases, the modulus of resin matrix increases, and the Poisson’s ratio of unidirectional carbon fiber composites laminates decreases. It was found that the longitudinal compressive strength of carbon fiber composites increases with the resin matrix crosslinking density increasing. But it had not found that the crosslinking density of resin matrix have obvious effects on the compressive modulus of unidirectional composite laminates.In the second scheme, the example of GCT800/S500M/5% has the highest modulus 4.45 GPa, as the content of thermoplastic components increased, the modulus of the resin reduced to the lowest 4.1GPa. The longitudinal compressive strength of carbon fiber composites also reduced from 1467.71 MPa to 1141.63 MPa with the content of PI increasing.The study on the resin and carbon fiber made by the first scheme showed that, as the content of thermoplastic components increase, the modulus of resin matrix increases, and the Poisson’s ratio of unidirectional carbon fiber composites laminates decreases. It was also found that the longitudinal compressive strength of carbon fiber composites increases with the resin matrix crosslinking density increasing. But it had not found that the modulus of resin matrix have obvious effects on the compressive modulus of unidirectional composite laminates.The two schemes came to the conclusion that the increasing in modulus of resin matrix is beneficial to improve the longitudinal compressive strength of carbon fiber composites but didn’t have obvious effects on the compressive modulus of unidirectional composite laminates.