Title: Energy Characterization for Brittle Material Response Under Uniaxial Compression Through Ultrasonic Scanning

Author(s): F. F. Tang

Publication: Symposium Paper

Volume: 143

Issue:

Appears on pages(s): 227-256

Keywords: compression; concretes; degradation; energy; material properties; nondestructive tests; ultrasonic tests; Materials Research

Date: 5/1/1994

Abstract:
Various researchers have attempted to establish correlation between mechanical properties of brittle materials and ultrasonic measurements. Recently, extensive experiments, including ultrasonic scanning tests, strain gage tests, and combined ultrasonic scanning and strain gage tests, have been processed to study the degradation mechanisms and surface effects in concrete-like brittle materials. In this paper, attention is restricted to the variation of energy dissipation with external load level and the relationship between mechanically dissipated energy and ultrasonically dissipated energy for brittle materials under uniaxial compression. Some typical ultrasonic scanning readings are presented. The load-level-dependent relationship between ultrasonically dissipated energy and mechanically dissipated energy is identified and discussed. It is also pointed out that an energy-based degradation instability theory is verified qualitatively by the energy diagram obtained through the experiments. The findings may be applicable to concrete with minor modifications. However, further work would be necessary to draw a firm conclusion.