Nonlinear elastic response of thermally damaged consolidated granular media

Abstract

The mechanical properties of consolidated granular media are strongly affected by large temperature changes which induce the development and localization of stresses, leading in turn to damage, e.g., cracking. In this work, we study the evolution of linear and nonlinear elasticity parameters when increasing the temperature of the thermal loading process. We prove the existence of a link between linear and nonlinear elasticity properties. We show that the change of the nonlinear elasticity parameters with the increase in the thermal loading is larger at the lower temperatures than the corresponding change for the linear parameters, suggesting that nonlinear elasticity can be exploited for early thermal damage detection and characterization in consolidated granular media. We finally show the influence of grain size upon the thermal damage evolution with the loading temperature and how this evolution is mirrored by the nonlinear elasticity parameters. V

Quantitative linear and nonlinear resonance inspection techniques and analysis for material characterization: Application to concrete thermal damage

“…Because of the small diameters of inclusions, M samples exhibit a density of ITZ considerably higher than HPC. Recent results in plaster 26 and in concrete 27 show that the sizes of inclusions (respectively gypsum crystals and aggregates) play a key role on the nonlinear behavior.…”

Ultrasonic Monitoring of the Interaction between Cement Matrix and Alkaline Silicate Solution in Self-Healing Systems

“…It was conducted in accordance with the Scaling Subtraction Method (SSM) procedure and therefore allowed taking into account the contributions to nonlinearity due not only to higher order harmonics generation (see Section 3.2), but also to the nonlinear attenuation and phase shift phenomena, as pointed out in [43]. As fully detailed in previous works [30,44,45,53], the SSM protocol consisted of:exciting the specimens using a sequence of pulses at various amplitudes $A_i$ in the range 50 mV–15 V (by means of the same equipment described in Section 2.3). More specifically, a rectangular pulse of width $t=10\mathrm{sans-serif\mu }$s was used;…”

Probing material nonlinearity at various depths by time reversal mirrors

“…Larger aggregates correspond to smaller inter-aggregate distances, which then leads to larger, localized thermal stresses in the cement paste, thus more frequent debonding. 16 In addition, debonding at the aggregate-cement paste interface is also driven by drying shrinkage, which occurs more easily closer to the surface, 17 especially at elevated temperature such as 400 C.…”

“…15 During thermal loading of concrete, the main damage (thus nonlinearity) source consists of debonding at the interface between the cement paste and the aggregates. 8,16 Figure 2(b) shows two vertical, digital cross-sections extracted from two X-ray tomographic datasets, one dataset for the reference sample at 20 C (top image), the other dataset for the sample thermally loaded at 400 C (bottom image). The arrows overlaid on top of the two images point to regions of potential debonding between the aggregate and the cement paste.…”