An elastoplastic model with damage based on the Thermodynamics of Frames

Resumo

The representation of the mechanical behavior of reinforced concrete structures aims to describe the
physical reality as accurately as possible, which for there are many available theories. Besides that, to go further
in those researches of physical representation, there are postulated formulations based on the science of
thermodynamics, which link the influence of mechanical behavior in the development of physical phenomena and
vice versa, through a systematic procedure that allows the determination of thermodynamic forces associated with
the state variables, which are able to represent these phenomena. Therefore, the model here presented is
underpinned on thermodynamic models that describe physical phenomena of reinforced concrete structures and
proposes a new damage law that allows the observation of the cracking evolution. A new cracking resistance
function that describes the energy release rate during the damage evolution is established since this new damage
law comes now from Gibbs Free Energy. Finally, in order to evaluate the accuracy of the new model, the results
obtained by the proposed model are compared with those given by the Lumped Damage Mechanics theory, which
presents itself as an efficient tool to describe the cracking appearance and evolution, for both analysis and
computational implementation.