Sensitivity of transverse Liquid Composite Moulding processing predictions to variations in constitutive data

Abstract

Transverse Liquid Composite Moulding (LCM) processes for the impregnation of thick parts have been gaining interest recently. Simulations of transverse LCM processes require accurate input of constitutive data to make useful predictions; however, accurate constitutive data are not always available and the magnitudes of deviations due to interpolation and extrapolation errors are not entirely known. The international out-of-plane compressibility and permeability benchmark exercises have shown large variations in both quantities, for each participant, and between different participants. In this work, a simulation model of transverse impregnation and compression for LCM processes is utilised to study the sensitivity of processing predictions to variations in constitutive data resulting from different fitting techniques. It is shown through a case study on saturated permeability measurements that significantly different predictions of the flow rate during permeability measurements arise from relatively small differences in the constitutive data. This study demonstrates the importance of accurate measurement and modelling of the compaction stress gradient and permeability for input into simulations.