ACOUSTIC EMISSION ANALYSIS WHEN CEMENT MORTAR SPECIMENS ARE SUBJECTED TO THREE POINT BENDING REPETITIVE CYCLES
Keywords:ACOUSTIC EMISSIONS, THREE POINT BENDING, WHITE CEMENT MORTAR, TSALLIS ENTROPY
AbstractTHIS WORK DISCUSSES THE EXPERIMENTAL RESULTS OF ACOUSTIC EMISSION (AE) RECORDINGS DURING REPETITIVE LOADING/UNLOADING LOOPS PRO-CESSES OF CEMENT MORTAR BEAMS SUBJECTED TO THREE-POINT BENDING. SIX REPETITIVE LOADING CYCLES WERE CONDUCTED AT A GRADUALLY HIGHER LOAD LEVEL UNTIL THE FAILURE OF THE SPECIMENS. THE EXPERIMENTAL RESULTS CLEARLY SHOW THE EXISTENCE AND DOMINANCE OF THE KAISER EFFECT DURING EACH LOADING LOOP. REGARDING THE AE DATA, ALTERNA-TIVE ANALYSIS WAS CONDUCTED USING THE IMPROVED B-VALUE, AND THE CUMULATIVE ENERGY BEHAVIOUR. BOTH QUANTITIES CONSIDERED, SHOW QUALITATIVE AND QUANTITATIVE CHARACTERISTICS THAT COULD BE USED AS PRE-FAILURE INDICATORS. IN ADDITION, A NOVEL STATISTICAL PHYSICS ANAL-YSIS INVOLVING THE AE INTEREVENT TIMES WAS CONDUCTED BY CALCULAT-ING THE CUMULATIVE PROBABILITY FUNCTION P(>Î´Ï) THAT FOLLOWS A Q-EXPONENTIAL EQUATION. THE ENTROPIC INDEX Q AND THE RELAXATION PARAMETER Î²Q OF THIS EQUATION SHOW SYSTEMATIC CHANGES DURING THE DIFFERENT STAGES OF THE FAILURE PROCESS. THE LAST CYCLE LED TO A Q VALUE EQUAL TO 1.42, IMPLYING THE UPCOMING FRACTURE WHICH IS IN GOOD AGREEMENT WITH PREVIOUS RESULTS OBTAINED FROM A WIDE RANGE OF FRACTURED MATERIALS.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License [CC BY] that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).