JEC COMPOSITES MAGAZINE - Issue #93 - December 2014 - 56

multimaterial

abling more precise control over the distance
between bushings, a pre-compression of the
rubber, and in general a robust, cost-effective
process. The plate connecting to the ball joint
is bolted directly onto the composite shells.
The economic and cycle time constraints that
correspond to requirements in the automotive
industry are being implemented within the
project for a high-output composite production line that Cetim will set up at the Technocampus Composites in Nantes in 2015.

Conclusions

Fig 8 : Distribution of targets glued to the composite jib / Metal/composite assembly: bolted/adhesive-bonded

We can conclude from this that the calculations correlate well,
since the displacement calculated for 3.2 T was 177 mm, and the
displacement extrapolated from the measurements at 2.5 T was
173 mm (average value) (fig 8).
Composite wishbone
Cetim recently presented a wishbone made of carbon fibre reinforced thermoplastic. The prototype part enabled a more than 50%
weight saving compared to the metal equivalent. Its fabrication
involved a number of participants besides Cetim, including PSA
Peugeot Citroën and Onera. The wishbone can be incorporated
directly into current vehicles.
The goal was challenging: to meet the extremely complex specifications for this safety component in terms of stiffness, fatigue
strength, crashworthiness, and external stresses from things like
stone chips and de-icing salts, not only for the part itself, but also
for the connections to the engine cradle and the steering pivot.
The innovation lies mainly with the development of a mould
system (patented by Cetim and a company called Compose) that
both moulds and welds the two wishbone components. Two impregnated plates are placed in the mould cavity
to be thermoformed simultaneously. The
mould rotates so as to place the two hot plates
face to face. The plates are then subjected to
infrared heat until they reach the welding temperature. When the mould is closed, the first
two plates are welded together and the next
two are thermoformed (fig 9).
The wishbone connections are created by
direct overmoulding of rubber bushings, en-

The assembly of multimaterial mechanical
systems requires starting with a complete
functional analysis in order to choose the
most suitable technology and to adapt the design as a function of this choice. The analysis
must be coupled with a characterization and
physical tests, at the very least on simplified subsystems, in particular to qualify the
dynamic, cyclic and ageing behaviour. n
More information:
pierre.chalandon@cetim.fr

References
[1] Laser-bonding of long fiber thermoplastic composites for structural assemblies. Knapp, W., et al. 2010, Physics Procedia, Vol. 5,
Part B, pp. 163-171.
[2] Laser Assisted Joining of Plastic Metal Hybrids. Roesner, A., et
al. 2011, Physics Procedia, Vol. 12, Part B, pp. 370-377.
[3] Potential of Laser-manufactured Polymer-metal hybrid Joints.
Bergmann, J.P. et Stambke, M. 2012, Physics Procedia, Vol. 39, pp.
84-91.
[4] On the feasibility of friction spot joining in magnesium/fiberreinforced polymer composite hybrid structures. Amancio-Filho,
S.T., et al. 2011, Materials Science and Engineering: A, Vol. 528, pp.
3841-3848.
[5] Experimental investigation of a novel hybrid metal-composite
joining technology. Ucsnik, S., et al. 2010, Composites Part A: Applied Science and Manufacturing, Vol. 41, pp. 369-374.

Fig 9 : A wishbone made of carbon fibre reinforced thermoplastic

56 jec composites magazine / No93 December 2014

JEC COMPOSITES MAGAZINE - Issue #93 - December 2014

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