Seminar by Nicolas Vacca

Impacts on reinforced concrete and tools for time-frequency analysis

The qualification of nuclear power plant equipment to resist an airplane impact requires the understanding and modelling of the dissipation in reinforced concrete. To this end, impacts tests have been done on a reinforced concrete mock-up, and time-frequency analysis of the free response evidenced amplitude-dependent behaviour. A simple rheological model containing damage and friction was able to reproduce this behaviour.

Time-frequency representations are usually expressed as integrals, and may take a complex analytical form. We will introduce some tools that can facilitate their manipulation and their exact or approximate evaluation: a mathematical formalism for integration that leads to an extension of the Dirac delta function to the complex plane, and an exponential signal model formalising the idea of a locally harmonic signal.