Comparison of thermal response mechanisms for three dimensional woven carbon fiber/epoxy resin composites under two measurement methods

Thermal conductivities of 3D woven carbon fiber/epoxy resin composites with different structures were measured by using transient hot-wire method and flash method, respectively. From the finite elemental simulations of 3D orthogonal woven carbon fiber/epoxy resin composites, it can be seen that, the roles of the warp, weft and Z-yarn in heat transfer process change with the change of the measuring method. By using transient hot-wire method, the thermal conductivity of 2.5D woven carbon fiber/epoxy resin composite is higher than warp-reinforced 2.5D, but lower than 3D orthogonal. However, the thermal conductivities of warp-reinforced 2.5D and 3D orthogonal woven carbon fiber/epoxy resin composites are less than 2.5D by using flash method. That is because of that, the same yarn in 3D woven carbon fiber/epoxy resin composites plays distinct roles in heat transfer process by using different measurement methods. Thermal conductivities of 2.5D woven carbon fiber/epoxy resin composites obtained by using transient hot-wire method and flash method increase with the increasing of fiber volume fraction. In addition, the increase of thermal conductivity obtained by flash method is more obvious, which is caused by the crime of warp. Based on these investigation. it can be concluded that the thermal response mechanisms of 3D woven carbon fiber/epoxy resin composites under different heating modes are different.