Study on tension-driven deformation compensation and fiber volume fraction regulation method for flexible oriented three-dimensional woven composite preforms

As a critical forming parameter in the fabrication of three-dimensional (3D) woven composite preforms, fiber tension plays a significant role in both the forming process and the structural integrity of the preform. In this study, based on the flexible oriented three-dimensional woven (FO3DW) technique, the effects of pre-needle fiber tension and weaving speed on post-needle fiber tension were investigated, and a digital control model for fiber tension regulation was established. A tension-driven analytical model describing the deformation of the guide array under multi-structural weaving paths was developed. Additionally, a machine vision-based method for detecting tension-driven deformation of the guide array was proposed, with a maximum deviation of 25.56 % between the model predictions and experimental measurements. A compensation method for guide array tension deformation was further introduced based on parameter inversion, and its effectiveness was experimentally validated—the maximum deviation between the compensated and pre-weaving positions of the guide bars was 0.192 mm. The deformation reduction ratio reaching up to 93.77 %. Furthermore, a tension-regulated forming method for gradient fiber volume fraction preforms was proposed. Under the selected process parameters, the local fiber volume fraction was successfully tuned within the range of 34.64 % to 36.20 %.