Modeling and experimental investigation of out-of-plane deformation on mechanical performance of composites manufactured by ATL

The change of mold normal curvature along the trajectory may result in out-of-plane waviness during the automated laying process, on which the layup speed and temperature would have an effect. A new parameter, deformation rate, was defined by combining the effect of mold curvature change rate and layup speed. A predicting model was proposed based on the fiber waviness and interlaminar sliding model to calculate the relationship between stiffness retention and the layup process parameters, including deformation rate and temperature. An experimental study on the effect of different deformation parameters on the tensile performance of composites was carried out based on a new manufacturing method of plated specimens with different levels of waviness by means of a four-point bending fixture. The experimental results showed that when the deformation temperature increases from 20 degrees C to 80 degrees C, the tensile strength increases first and then decreases while the tensile module keeps increasing. While the deformation rate decreases from 0.40 to 0.04mm(-1)/s, both tensile strength and module showed an increasing trend. The predicting model being validated by experimental results can be utilized to optimize the layup process parameter to satisfy the quality and efficiency requirements.