Acoustic emission detection in concrete specimens: Experimental analysis and lattice model simulations

Abstract

In civil engineering, a quantitative evaluation of damage in materials subjected to stress or strain states is of great importance due to the critical character of these phenomena, which may suddenly give rise to catastrophic failure. From an experimental point of view, an effective damage assessment criterion is provided by the statistical analysis of the amplitude distribution of the acoustic emission signals generated by growing microcracks. A classical way to work out the amplitude of acoustic emission signals distribution is the Gutenberg-Richter law, characterized by the b-value parameter, which systematically decreases with damage growth. The damage process is also characterized by a progressive localization that can be modeled through the fractal dimension 2b ¼ D of the damaged domain. In the framework of continuum damage mechanics, the progressive deterioration of the material that causes formation of macro-cracks is described by means of phenomenological damage variables usually introduced in classical constitutive relationships. Nevertheless, taking into account discrete damage mechanics, lattice models are particularly suitable to reproduce the generation of acoustic emission events, arising from the materials, during the different stages of damage growth. These models are also fundamental for the application of advanced statistical methods and non-standard mathematical methods, e.g. fractal theory. Starting from these considerations, in this work a b-value analysis was conducted in laboratory on two concrete specimens loaded up to failure. One was a prismatic specimen subjected to uniaxial compressive loading and the other was a pre-cracked beam subjected to a three-point bending test. The truss-like discrete element method was used to perform numerical simulations of the testing processes. The test results and the results of the numerical analyses, in terms of load vs. time diagram and acoustic emission data, as determined through b-value and signal frequency variations, are compared and are seen to be in good agreement.

A new method to estimate location and slip of simulated rock failure events

“…Seismic wave amplitude is correlated to seismic moment (Itturrioz et al, 2013), where the scalar seismic moment is defined as…”

“…Berdowski et al, 2013;Boominathan et al, 2014;Burks and Kumosa, 2014;Fu et al, 2014;Hamdi et al, 2013;Njuohvic et al, 2014;Sause et al, 2013), and concrete (e.g. ElBatanouny et al, 2014;Elfergani et al, 2013;Hu et al, 2013;Itturrioz et al, 2013;Kawasaki et al, 2013;Kencanawati et al, 2013;Ohno et al, 2014;Shahidan et al, 2013;Zhu et al, 2010).…”

Mechanical Properties and Acoustic Emission Properties of Rocks with Different Transverse Scales

“…In terms of researches on mechanical properties and acoustic emission properties of rocks, scholars focus on analyzing characteristics [5][6][7][8][9][10] of rocks with standard scale (diameter 50 * 100 mm) under compression, tension, and shearing conditions. Restricted by the test conditions, seldom do scholars study mechanical properties and acoustic emission properties of rocks under scale effects.…”

Acoustic Emissions analysis of a four-point bending test on a Reinforced Concrete beam

“…This has been codified by the Japanese standard [10]; 2. The use of b-value [11][12][13][14], and, more recently, by Carpinteri et al [15], which proposed analytical correlation with theory of fracture [16] and numerical models [17] [18]. The approach of linking AE experimental data to numerical simulations seems interesting, and quite unexplored at this stage; 3.…”