Establishment of a reference method for one-dimensional permeability measurement in VaRTM process using plain-woven fabrics

This study addresses the challenge of reducing variability in permeability measurements for the vacuum-assisted resin transfer molding (VaRTM) process, which is essential for accurately evaluating resin impregnation behavior. Initial evaluations were conducted at two different institutions, comparing permeability in both the 0° and 90° fiber directions of carbon fiber plain-woven fabric to identify key challenges contributing to variability. The comparison revealed significant differences in permeability results due to inconsistencies in experimental settings and measurement methods. Based on these findings, improvements were proposed, including temperature control, adjustment of resin impregnation levels, and standardization of VaRTM settings and measurement methods. These improvements were then applied to the 0° direction under the minimum nesting condition. Results showed that the improved methodology significantly reduced variability, with differences between bottom and area measurements being less than 10%, and an average variability of 17%. This approach effectively minimizes variability in permeability measurements, enhancing the reliability of the VaRTM process.