High Strain Rate Behaviour of Composites

This work measures how cement composites, textiles, and polymer composites respond at strain rates far above those of a standard test and builds that rate dependence into the constitutive models, using the servo-hydraulic high speed frame characterised in the containment programme.

The materials covered run well beyond concrete: strain-hardening cement composites and textile reinforced concrete, basalt, carbon, glass and aramid fabrics, carbon and aramid fibre reinforced polymers under combined rate and temperature, glass fibre reinforced polymer, and closed-cell aluminium foam from quasi-static rates upward.

Two findings recur. Tension stiffening and the distribution of cracking in textile reinforced concrete change with rate, so a design value taken from a slow test does not transfer. And failure tends to localise differently at rate, which is why the high-speed tension and impact results have to be correlated rather than treated as separate tests.

Much of the textile work was carried out with Viktor Mechtcherine and Marko Butler at TU Dresden and with Flavio de Andrade Silva, and the polymer composite work with Deju Zhu and colleagues at Hunan University.