Tensile properties of glass fiber reinforced polypropylene composite and its carbon fiber hybrid composite fabricated by direct fiber feeding injection molding process

The elastic modulus of a glass fiber reinforced polypropylene composite and its hybrid carbon fiber composite fabricated by direct fiber feeding injection molding (DFFIM) process were evaluated by using the Classical Calculated Method and the modified Tsai‐Hill criterion based on the laminate analogy approach method, respectively. The results were in good agreement with the experiments for both the glass fiber reinforced polypropylene composite and its hybrid composite. In addition, the modified Tsai‐Hill criterion shows more accuracy than the Classical Calculated Method in predicting the Young's modulus. The tensile strength of the composites was investigated by utilizing the modified Kelly‐Tyson equation and Modified Tsai‐Hill criterion. The results of the modified Kelly‐Tyson equation are closer to the real value. The interfacial shear strength between carbon fiber and polypropylene in the hybrid composite manufactured by the DFFIM process was analyzed by using the modified Kelly‐Tyson equation. POLYM. COMPOS., 39:3564–3574, 2018. © 2017 Society of Plastics Engineers