Accession Number:

ADA265743

Title:

Characterization of Acoustic Emission Source to Identify Fracture in Concrete

Descriptive Note:

Final rept. Dec 89-Nov 92,

Corporate Author:

NORTHWESTERN UNIV EVANSTON IL DEPT OF CIVIL ENGINEERING

Personal Author(s):

Report Date:

1993-04-01

Pagination or Media Count:

81.0

Abstract:

This report describes the theoretical basis, experimental approaches, and results of research to evaluate fracture properties of concrete using quantitative acoustic emission AE analysis techniques. Analytical tools were developed to process AE data. These tools included improvements in P-wave arrival analysis, AE source location calculation, and multichannel deconvolution techniques. The microfracture characteristics of mortar was evaluated using a three dimensional moment tensor analysis. Microcracking was found to be primarily mixed mode and shear. A new technique for testing concrete in uniaxial tension was developed. Using this technique localization and strain-softening behavior was examined. Microcracking was found to be evenly distributed throughout the specimen until about 80 of peak load. At this point localization began and the microcracks coalesced into a single macrocrack.... Acoustic emission, Microcracking, Quasi-brittle materials, Damage localization.

Subject Categories:

  • Ceramics, Refractories and Glass
  • Acoustic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE