This presentation was made at the 2019 NAFEMS World Congress in Quebec Canada
Polymer matrix composite deposition processes, such as automated fibre placement (AFP), forming, or filament winding, are effective manufacturing methods that improve repeatability, enable tailoring of material orientations, and reduce time and cost when compared to more labour-intensive alternatives. Although these technologies are widely used to produce high quality parts, they often lead to defects that may cause manufacturing delays and can ultimately result in scrapping of expensive parts. In such cases, a resource intensive trial and error approach is traditionally applied to determine optimum processing conditions that minimize the occurrence of defects.
The simulation of pre-gelation deposition processes presents significant challenges that come from geometric non-linearity, the inclusion of multiple contact interfaces, and the heterogeneous nature of uncured prepreg. In this state, the resin acts as a highly non-linear, rate- and temperature-dependent viscoelastic material while the fibres act as very stiff elastic solids.
This paper presents a finite element simulation approach, using COMPRO and ABAQUS, to predict the occurrence of defects in the forming and consolidation steps of the manufacturing process of thermoset matrix fibre reinforced composites. A discrete modelling strategy is used whereby each ply of the composite laminate is discretized by a layer of compliant coupled P-U solid elements superimposed with stiff shells elements at the top and bottom surfaces. The model is then exercised using linear elastic material models with parameter values calibrated based on experimental bending and shear testing of unidirectional prepreg.
Simulation results show good agreement with experimental forming trials and other work found in literature in terms of deformation mechanisms and defects observed.
|Date||18th June 2019|
|Organisation||Convergent Manufacturing Technologies Inc|