Skip to Main content Skip to Navigation
New interface
Theses

Suivi temporel de la dynamique des structures : apports du théorème fluctuation-dissipation et de la dynamique lente pour l'évaluation de l'intégrité des structures de génie civil

Abstract : During strong seismic loadings, a structure may be damaged. This results in the appearing of cracks and then a reduction of the elastic properties of the structure. The degradation remains only transitory in the case of smaller seismic events. It consists in a sharp disruption of both the frequency and damping followed by their slow recovery to their initial values. This non linear phenomenon is called Slow Dynamics. It is explained by the gradual closing of the cracks which were initially present in the material and which were opened during the loading. We observed in the laboratory that the analysis of the Slow Dynamics in a beam before and after it is damaged allows to detect the increase of the crack density. The different sensitivties of the modes regarding a local damaging indicates a track to develop a method to locate the damages. The study of the Slow Dynamics in civil engineering structures demonstrated the possibility to detect the damaging also in this kind of system. The continuous monitoring of the damping highlighted a linear relationship between damping and the intensity of the ambiante vibration in the case of both the beams and real case structures. We explain this relation by applying the Fluctuation-Dissipation to these systems. Laboratory results and the proximity of the expression of the linear relationship wit hthe equations used in the theory of the Slow Dynamics suggest a dependency of this phenonmenon on the density of heterogeneities in the structure. Further research is however required in order to fully explain our observations and thus, to use them to monitor the state of health of structures.
Document type :
Theses
Complete list of metadata

Cited literature [80 references]  Display  Hide  Download

https://theses.hal.science/tel-01701948
Contributor : ABES STAR :  Contact
Submitted on : Tuesday, February 6, 2018 - 12:59:07 PM
Last modification on : Sunday, May 1, 2022 - 4:02:55 AM
Long-term archiving on: : Saturday, May 5, 2018 - 6:38:11 AM

File

BROSSAULT_2017_archivage.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01701948, version 1

Citation

Marc-Antoine Brossault. Suivi temporel de la dynamique des structures : apports du théorème fluctuation-dissipation et de la dynamique lente pour l'évaluation de l'intégrité des structures de génie civil. Modélisation et simulation. Université Grenoble Alpes, 2017. Français. ⟨NNT : 2017GREAU031⟩. ⟨tel-01701948⟩

Share

Metrics

Record views

348

Files downloads

145