Influence of the depth and morphology of real cracks on diffuse ultrasound in concrete: A simulation study

Abstract

The aim of the present paper is to simulate the propagation of diffuse ultrasonic energy in concrete in the presence of a real crack. The numerical model is presented and validated by the comparison with experimental data from the literature. Unlike most of the studies which consider a crack as a notch, a realistic crack morphology exhibits partial contacts along its lips. These contacts are modeled in order to study their influence on the diffusion parameters. The feasibility of determining the contact density of the crack is shown, revealing practice implications for non-destructive crack sizing and imaging in concrete.

Applying diffuse ultrasound under dynamic loading to improve closed crack characterization in concrete

“…From a qualitative point of view, one can notice the large sensitivity of Δt to the depth of the crack with a maximum variation of about 500%. Quiviger et al 10 numerically show that even a single, 1mm size, contact can lead to a few microseconds ATME variation in the present samples. At the same time, the contact density makes the ATME varying in the same range 10 .…”

“…Quiviger et al 10 numerically show that even a single, 1mm size, contact can lead to a few microseconds ATME variation in the present samples. At the same time, the contact density makes the ATME varying in the same range 10 . Thus present variations and complex signatures are mostly due to a combination of these effects.…”

“…The dynamical behavior of the crack is complex and, to our knowledge, no former study deals with this topic. ATME is shown to decrease when the contact density along the crack increases 9,10 . Present data are in agreement with that statement.…”

“…The presence of hysteresis may be due to the viscoelastic nature of cement as well as the hysteretic opened/closed behavior of the crack. A real crack in concrete exhibits some partial contacts all along its lips 10 . It is reasonable to assume that these contact zones are hysteretic during dynamical loading.…”

“…These studies show the sensitivity of diffuse ultrasound to the presence of opened zone either for notches or opened cracks. This is also the case for closed cracks which exhibit partially opened zone along its lips 9,10 .…”