JEC COMPOSITES MAGAZINE - Issue #81 - May/June 2013 - 62

cost prediction
More information
FACC AG – Research & development
FACC AG is Austria’s largest supplier of composite components for the
civil aerospace industry. The commitment to deliver the best solution
makes FACC a leading partner for lightweight components in aerostructures, engines and interiors.
www.facc.com/en/Services/Research-Development/Research-Development
Composites processing chair, University of Leoben
The mission of the chair is to develop manufacturing techniques for
the production of fibre-reinforced polymer materials, concentrating
on the development, automation and simulation of the individual
manufacturing processes.
www.kunststofftechnik.at/cms/1/21579/
Fig. 3: Typical metallic annulus filler [4]
Tab.2: Constraints for an annulus filler (excerpt)

Annulus filler requirements

Remarks

Part count

~1000 [P/a]

Projected area

~98,000 [mm²]

Surface tolerances

very narrow

Minimum radii

3 [mm]

Curvature

double

Part tolerances

very narrow

balancing

UD fibres

< 10%

impact

Tooling complexity

medium

Material qualification

prepreg, RTM

balancing

clave – is reduced by the higher raw material costs. This shows
though, that OoA prepreg could be considered for further programmes, when the corresponding raw material costs achieve
higher market acceptance. Tape laying is hindered by geometry,
as the part is too small to even consider automated tape laying.
Infusion was not considered by the project team due to missing
experience. Although not perfectly matching the component’s
needs, this case highlights the necessity for neutral advice.

Outlook

customer req.

manufacturing with out-of-autoclave prepreg as runner up and
conventional prepreg as close third. This matches the decision
of the project team, although conventional prepreg and OoA
prepreg change places due to personal experience (Figure 4).
The main success point for RTM is the best tolerance behaviour
in part dimensions and surfaces. Its main issue is the high tooling costs, but this is reduced by the high part count.
For prepreg, the main advantage is the customer requirements,
but the limited autoclave availability hinders its success. This is
company specific though, and can be different for other manufacturers. OoA prepreg proves to be almost equal to prepreg
technically, but is limited in availability and aerospace qualification. Its main economic advantage – the avoidance of an auto-

The programme is currently in its early alpha stage. While the
input-based concept seems to provide fairly realistic results, the
quality of the input is still heavily dependent on the user. An
average subset of input data for comparison purposes will be
created to reduce human influence. Usability will be improved
continuously. FACC AG and the University of Leoben have
set up a Christian Doppler Laboratory to jointly continue the
research on cost-efficient production techniques. n
More information:
www.facc.at
References
[1] “Fibre composite aircraft – capability and safety”, ATSB transport safety research
report, 2007, Aviation research & analysis report AR-2007-021
[2] “System Engineering and Analysis - 3rd Edition”, Walter J. Fabrycky, Benjamin
S. Blanchard, 1998, Figure 2.11
[3] “Development of a theoretical cost model for advanced composite fabrication”,
Timothy Gutowski et al., M.1994 Composites Manufacturing 5 (4) , pp. 231-239
[4] “Annulus filler”, Stephen Jonathan Dimelow, 2012, US Patent 8287239
[5] “Advanced composite cost estimating manual”, Northrop Cooperation, 1976
[6] “Complexity Based Cost Estimation Model for Composite Aerospace Structures”,
Jayanthi Kumar, Elizabeth Kendall, 2004, Royal Melbourne Institute of Technology
[7] “Cost modeling for manufacturing of aerospace composites”, Ma Weitao, 2011,
Cranfield University
[8] “WEB based cost estimation models for the manufacturing of advanced composites”, Joshua W. Pas, 2001, Massachusetts Institute of Technology
[9] “Knowledge based cost modeling of composite wing structures”, Wim Verhagen
et al., 2010, University of Delft
[10] “Cost optimization of composite beams using genetic algorithms”, Ahmed B.

Fig. 4: Comparisons of processes ¬– software vs. human (normalized to 100%)

62 jec composites magazine / No81 May - June 2013

Senouci, Mohammed S. Al-Ansari, 2009, University of Qatar

http://www.facc.com/en/Services/Research-Development/Research-Development http://www.kunststofftechnik.at/cms/1/21579/ http://www.facc.at

JEC COMPOSITES MAGAZINE - Issue #81 - May/June 2013

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #81 - May/June 2013