Dynamic behaviour of fiber-reinforced composites
Dynamic testing of brittle materials with low fracture strains, such as composites or ceramics, is challenging. Indeed, the commonly used Split Hopkinson bar setups have been developed for large deformation materials, typically metals. In particular, the following aspects need to be addressed carefully:
- Achievement of early quasi-static equilibrium in the sample, important to generate a reliable stress state before sample failure.
- Local, preferably full-field, measurement of the strain in the sample, since traditional strain measurement is not accurate enough to capture the generally low deformations.
The quasi-static equilibrium can be addressed by a proper design of sample geometries. On the other hand, the accurate measurement of local deformations can be achieved by the use of non-contact measurement techniques relying on high-speed imaging and Digital Image Correlation (DIC) processing.