Abstract:
This thesis has investigated composite-honeycomb sandwich materials commonly used
in Formula 1 nosecone structures. Experimental work has investigated their failure
behaviour under static and dynamic crash loading, from which new constitutive failure
laws for implementation in the explicit Finite Element code PAM-CRASHTM have been
proposed.
An investigation using an improved Arcan apparatus has been conducted to establish
the mixed shear-compression properties of the honeycomb. An investigation has also
been performed to establish relationships between in-plane deformation and out-ofplane
compression properties. These relationships have been identified and successfully
implemented into a honeycomb solid element material model available in PAMCRASHTM.
A further investigation to represent honeycomb using geometrically
accurate shell representation of the honeycomb has also been presented. This model was
shown to reproduce trends observed during testing.
The composite skin material has also been experimentally investigated and presented.
This investigation made use of digital image correlation to examine the onset of intralaminar
shear failure mechanisms, from which a non-linear damage progression law was
identified. This law was successfully implemented into the Ladevéze damage model in
PAM-CRASHTM for composite material modelling and has been shown to improve the
representation of in-plane shear damage progression and failure.
A series of experimental investigations to examine the energy absorbing properties of
the sandwich have been conducted and presented. These investigations include three
point bend flexural testing and edgewise impact loading. Failure mechanisms in the skin
and core have been identified for each loading case. Experimental findings were used to
assess the capability of PAM-CRASHTM for sandwich material modelling. This
investigation has highlighted deficiencies in the material models when representing the
sandwich, specifically with the existing composite skin and honeycomb models.
Improvements introduced to the core and skin material models have shown some
improvement when representing sandwich structures.
