Composite Group ManufacturingMontana State University

Pancasatya “Tiok” Agastra27 November 2012

Impetus• Superior mechanical performance of large

composite structures through energy efficient manufacturing– Substructural details: ply drops, sandwich

construction, ply joints

• Low cost manufacturing and increased turnover rate

• Understanding of resin reaction kinetics

Approach• Quantification of manufacturing parameters

– Industry-accepted composite manufacturing method: Resin Transfer Mold (RTM), Vacuum Bag

• Manufacturing modeling using FEA– Fluid flow, including free surface analysis– Heat transfer with autocatalytic reaction kinetics– FEA packages: ANSYS FLOTRAN, ANSYS CFX,

COMSOL

Governing Equations for Manufacturing Modeling

uk

uuuu ηgρpρηtuρ T

Navier-Stokes Equation with Darcy’s Law

QTCρTtTCρ PP uk

Conduction and Convection

nm21 α1αkk

dtdα

α

0nm

21

t

0 α1αkkdαdt

αΔHHΔ Enthalpy rate of release

Autocatalytic Rate Law

Integral Form of the Rate Law

FLUIDFLOW

HEATTRANSFER

REACTIONKINETICS

Manufacturing MethodsRTM Vacuum Bag

Manufacturing Parameter Quantification & Resin Characterization

Flowrate Temperature

Differential Scanning Calorimetry

Manufacturing Milestone

Blade Root Manufacturing

“Brick” Laminate

Microflow-Scale Modeling• Resin flow in wind turbine blade materials is a complicated local and

global phenomenon (channel flow plus D’Arcy flow in strands)

Baseline Fiber Strand Permeability 6.16E-14 m²

Higher Fiber Strand Permeability 6.16E-12 m²

TRANSVERSE FLOW AXIAL FLOW

Knytex D155 Cross Sectional Area

Heat Transfer Modeling

RTM Vacuum Bag

Fabric Compaction

COMSOL Coupled-FieldThermal-Fluid-Convection

RTM with incoming resin

Large Scale Application

Future Work• Flow properties

– Viscosity and degree of cure correlation– Permeability and compaction

• Chemical and thermal properties– Thermal conductivity– Enthalpy release rates and heating rate