Hemispherical Molding Experiment and Simulation of Unidirectional Carbon Fiber Prepreg

To study the deformation law and forming defects of hemispherical molding of unidirectional carbon fiber reinforced polymer (UN-CFRP), hemispherical molding experiments were carried out, and a three-dimensional finite element model of single-ply UN-CFRP hemispherical molding was established. The results show that the established finite element model can accurately predict the molding deformation law and forming defects of UN-CFRP. The results indicate that the fiber at the top of the sample is uniformly distributed; the fiber on both sides of the sample top and parallel to the fiber direction is local dispersion; the fiber at both sides of the bottom is trapezoidal splitting. The results at the bending corner show that the bending quality is better when the angle between the fiber direction and the tangent of the circular bend is in the range of 70-90°; it is easy to produce extrusion wrinkling when the angle between the fiber direction and the tangent of the circular bend is 15-70°; it is easy to produce extrusion accumulation when the angle between the fiber direction and the tangent at the circular bending is in the range of 0-15°. The results of cross-ply UN-CFRP hemispherical molding show that the full spreading property is good, and there is no obvious fold in the bending part.