Study on inter-ply friction between woven and unidirectional prepregs and its effect on the composite forming process

Abstract In this paper, the inter-ply frictional behavior between woven and unidirectional (UD) carbon/epoxy prepregs was studied and its effect on the forming process was investigated. The coefficient of friction (COF) was obtained according to the fiber direction of the prepreg, the temperature, the sliding speed and the pressure. Also, the forming properties such as shear modulus and bending stiffness were measured. In addition, hybrid woven/UD prepregs were formed by U-shape mold and the forming process was implemented by commercial software PAM-FORM. Then, the influence of the frictional resistance along the fiber direction was observed. As a result, it was found that the difference in the interlayer displacement was significantly affected by the frictional behavior according to the fiber direction, and it changed the shear angle distribution and wrinkles after the forming process.