Title:
Rate-Sensitive Micromechanical Model for Concrete
Author(s):
Oipankar Chandra and Theodor Krauthammer
Publication:
Symposium Paper
Volume:
175
Issue:
Appears on pages(s):
281-292
Keywords:
compressive strength; cracking (fracturing); damage; loads (forces);
tests
DOI:
10.14359/5927
Date:
12/1/1998
Abstract:
A micromechanical damage model for concrete capable of taking into account the effect of highly time-varying load (time-varying stress) is outlined here. Giving primary consideration to concrete-type material, it is shown how an existing self-consistent rate-insensitive model can be modified and extended to induce rate dependency of concrete with pre-existing damage (cracks). The variations of several fracture mechanics parameters of concrete, viz., stress intensity factors, fracture toughnesses, etc., under the influence of high loading rates are investigated; the role of inertia of the material is explained and quantified. The process of crack evolution including crack kinking and nucleation under tensile and compressive stress-field has been thoroughly considered along with all possible situations that may arise. The resulting rate-sensitive model has been codified for high-speed computer and a few experiments have been replicated to validate it.