Experimental parametric study of flow‐induced fiber washout during high‐injection‐pressure resin transfer molding

Abstract Fiber washout during high‐injection‐pressure resin transfer molding (HIPRTM) is an unwanted emergent defect. This article addresses the mechanisms that cause fiber washout during manufacturing of composite parts by HIPRTM. The key focus of this work is on one‐dimensional flow experiments using HIPRTM process in which in‐plane drag force due to high resin pressures is responsible for the fiber washout. An experimental parametric study is conducted to investigate the influence of the fabric architecture, number of plies, and injection pressure to identify controllable process and material factors to prevent fiber washout. The results show that as the ratio of tangential force between the mold/ply and the drag force increases, one would expect fiber washout to occur and either cause fiber waviness or form wrinkles and dry spots. The fiber washout distances measured from the experiments were used to validate the model developed in our previous work. The numerical simulations by LIMS qualitatively agreed with the experimentally measured behavior. It is concluded that the formation of dry spot is due to the contribution of two main factors: (a) very significant permeability reduction in the wrinkled region and (b) some race‐tracking.