Finite element modeling of the filament winding process

A finite element model of the wet filament winding process was developed. I n particular, a general purpose software for finite element analysis was us ed to calculate the fiber volume fraction under different process condition s. Several unique user defined subroutines were developed to modify the com mercial code for this specific application, and the numerical result was co mpared with experimental data for validation. In order to predict the radia l distribution of the fiber volume fraction within a wet wound cylinder, th ree unique user defined subroutines were incorporated into the commercial f inite element code: a fiber consolidation/compaction model, a thermochemica l model of the resin and a resin mixing model. The fiber consolidation mode l describes the influence of the external radial compaction pressure of a n ew layer as it is wound onto the surface of existing layers. The thermochem ical model includes both the cure kinetics and viscosity of the resin. This model analyzes the composite properties and tracks the viscosity of the re sin, which is a function of the degree of cure of the resin. The resin mixi ng model describes the mixing of "old" and "new" resin as plies are compact ed. Validations were made by comparing image analysis data of fiber volume fraction in each ply for filament wound cylinders with the FEM results. The good agreement of these comparisons demonstrated that the FEM approach has can predict fiber volume fraction over a range of winding conditions. This approach, then, is an invaluable tool for predicting the effects of windin g parameters on cylinder structural quality. (C) 2001 Elsevier Science Ltd. All rights reserved.