A study of the deformation of weft-knit preforms for advanced composite structures Part 2: The resultant composite

This paper investigates the formability (i.e. the ability of a textile preform to conform to a 3-D shape) of weft-knit reinforced composites via the use of a composite case study (helicopter door track pocket), including the cutting plan methodology used for composite fabrication in the RTM process. The difficulties encountered during composite fabrication with specific preform types are discussed and expanded on the findings of the dry preform simulated formability results reported in part 1. The formability in the composite part was investigated through the deformation patterns of the various preform structures. The formability is specifically expressed as distributions of the preform deformation. The results of the composite case study showed that formability is influenced by the extensibility of the preform, the quality of the subsequent composite in terms of the degree of faults, and the distribution of the preform elongation in the composite.