Discontinuous fiber composites (DFC) are produced by
compression molding of prepreg chips which are made
of a combination of unidirectional fiber and a Thermoset
or ThermoPlastic matrix. In some cases, matrix is made
of thermoset which consolidate through a chemical/
cure reaction at elevated temperature. However, when
the curing cycle is not well monitored it can be observed
some cracks that appear between the chips due to
apparition of thermal stresses normal to two chips.
Due to their complex microstructure, these materials
request the definition of new dedicated methods in
order to capture accurately the local orientation and to
compute the local homogenized properties in order to
simulate correctly the curing and the design process.
Hence, the Digimat platform is used to build a complete
methodology to compute these residual stresses and to
take them into account during the design cycle of the part.
- Propose a complete methodology
to analyze Discontinuous Fiber
Composites: Understand the
effect of the local microstructure
on the behavior of the part.
- Improve the understanding of
the effects of the manufacturing
cycle parameters: Evaluate the
risk fo the apparition of defects
between the chips for a given set
of parameters of manufacturing (pressure, temperature histories).
Though their nature is different, this
procedure can be applied for both,
thermoset or thermoplastic resin.