Tensile properties and failure mechanism of carbon fiber reinforced epoxy composite with resin rich defects

The tensile properties of carbon fiber reinforced epoxy composite with resin rich defects caused by local fiber fracture were studied. The corresponding relationship between defect location and tensile properties was analyzed. It is found that the maximum and minimum tensile strength are observed when the defect is located at 1/3 of the sample and 1/2 of the edge of the sample, respectively whilst the intermediate strength is seen at geometric center of the sample provided the same defect size. When the defect is in the same position, the tensile strength decreases with the increase of defect size. The actual size and location of defects are detected by computed tomography (CT), and the tensile strength prediction model of carbon fiber reinforced epoxy composite with defects is established by using finite element simulation. The error between the simulation values and the experimental values is less than 10%, which shows the reliability of the finite element model. Moreover, the failure mechanism of the composites is analyzed with the simulation results.