Failure mechanisms are plotted in diagrams taking stress and temperature or environment as axes. Experiments have supported earlier work showing that microbuckle propagation can be modelled as a sliding crack. The ignition toughness has been modelled using a finite element model. Large scale bridging models for compressive failure of notched carbon fibre have been developed. Design criteria have been developed for the initiation and growth of damage from notches, and the effects of multi-axial loading have been included.
Compressive failure is generally by plastic microbuckling.
Experiments have investigated the propagation zone at the tip of such a microbuckle. An analysis treating the microbuckle as a crack and applying conventional fracture mechanics has been fruitful. In-situ scanning electron microscope experiments have been performed to study the microbuckle propagation phase. The collapse response is modelled by a simple fracture mechanics model. The fibre microbuckling phenomenon has been investigated for a stochastic distribution of fibre waviness and for a composite under multiaxial loading.