Title:
Micromechanical Studies of Crack Growth in Steel Fiber Reinforced Mortar
Author(s):
Samir Said and James A. Mandel
Publication:
Materials Journal
Volume:
86
Issue:
3
Appears on pages(s):
225-235
Keywords:
crack propagation; failure mechanisms; finite element method; metal fibers; microcracking; models; mortars (material); Materials Research
DOI:
10.14359/2417
Date:
5/1/1989
Abstract:
Cementitious materials have a deficiency in resisting tensile, impact, and other energy loadings. In this paper, a micromechanical finite element model is developed to simulate the response of a typical region of a fiber reinforced material load from the onset of load to failure. With this model, mechanical behavior of fiber reinforced cementitious materials can be studied, as the magnitude and distribution of the stresses in the matrix material, fibers, and fiber-matrix interface are calculated. The region investigated includes a crack front and the fibers nearest the crack front. The modes of failure considered are tensile failure and crack growth in the matrix material, failure of the fibers, and initiation and crack growth along the fiber-matrix interface. Side-cracked tension specimens with two rows of accurately positioned steel fibers were tested and analyzed with the model to verify it and study the mechanisms of failure in fiber reinforced cementitious materials. Analyses of the model show the mechanism of failure was sequential, with local failures such as crack growth and fiber delamination preceding overall failure of the specimens; and the properties of the fiber-matrix interface directly influence the composite material's resistance to crack growth. There was close agreement between the results of the testing and micromechanical finite element modeling of the side-cracked tension specimens. Thus, the model can be a useful aid in evaluating existing composites or in the development of new composites.