Séminaire Liquides/Mat. molle

Mardi 4 Octobre 2016 à 11h00.

Monitoring and Prediction of catastrophic mechanical phenomena

''Monitoring and prediction of catastrophic mechanical phenomena, such as collapse of buildings/structures, landslides and earthquakes, are very important for preventing disasters. However, in spite of many efforts, they are still considered to be essentially difficult or even impossible. In this talk, we show that the monitoring and prediction are possible in a specific mechanical system with high accuracy. Based on the concept of critical slowing down which is well established in statistical physics, we study so called snap-through buckling, where an arch structure (bridges, dams and tunnels) collapses suddenly beyond a critical load [1]. We succeed in predicting the occurrence of collapse of our laboratory arches by monitoring the fundamental frequencies of the system which go to zero as the system approaches the critical load [2]. We will discuss how it works and also introduce our trials applying to laboratory earthquake experiments. [1] A. B. Pippard, Response and Stability, Cambridge University Press (1985). [2] H. Ohtsubo, T. Yamaguchi, Y. Sawae, in preparation.''