Complex angle part fabricated by vacuum bag only process with interleaved dry fiber and prepreg

Abstract

This study used the vacuum bag-only process to fabricate angle composite parts on a complex-shape mold by employing interleaved unidirectional prepreg and dry fiber. The study focuses on the thickness variation along the angle part by analyzing the thickness distribution within the angle part by the statistic method. The corner thickness deviation (CTD) and angle deviation (AD) of the angle part were used to quantify the quality of the part by different process parameters and mold design. The results indicated that the CTD and AD were both linearly decreased with the increase of the part thickness. Besides, the part fabricated with the convex mold presented higher dimensional stability and uniformity as compared to that with the concave mold. In addition, we investigated the effect of caul plate applied at the corner regions, and the results showed that the lead caul plate could effectively improve the thickness change in the corner area in both the concave and convex mold. In order to fully understand the thickness variation of the part at the corner region, a semi-empirical model was proposed to forecast the corner thickness deviation of angle part. In this study, the prediction errors of the semi-empirical model for the parts by the concave and convex molds are 10% and 25%, respectively.