Modelling and experimental characterisation of high velocity impact on CFRP
R Vignjevic, Cranfield University, UK

This talk is addressing development of constitutive model for carbon fibre reinforced composite (CFRP) materials under high velocity impact loading. The development is done within the framework of irreversible thermodynamics and configurational continuum mechanics. The constitutive model is allows for modelling formation and propagation of shock wave in anisotropic material and damage and failure including shock wave propagation. The model comprises two parts: equation of state (EOS) which defines the material response under compression and shear part which defines the material response to shear deformation.

The damage model is represented at the continuum scale as a second order tensor, which is divided into the damage which results in volume change of the damaged material (e.g. voids, cavities) and damage related to shear deformation. Damage evolution based on the time to failure concept is coupled with a thermo elastic model and the shock EOS. The initiation of failure is based on a critical value of a specific dissipation function. Performance of the model is illustrated by few numerical examples where experimental data from high velocity impact tests is compared with the numerical results.