Title:
Cracks Development, Brittle Failure, and Design of Concrete Elements
Author(s):
Vitalii Mitrofanov and Pavel Mytrofanov
Publication:
Structural Journal
Volume:
122
Issue:
2
Appears on pages(s):
49-58
Keywords:
concrete elements brittle failure; critical crack length; fracture process zone (FPZ); rupture crack; strength design
DOI:
10.14359/51743293
Date:
3/1/2025
Abstract:
The limitations of known fracture mechanics (FM) models are noted, and to overcome them, a specific FM model was proposed based on modeling the stress distribution only along the crack fracture process zone (FPZ), with elastic concrete behavior out of the FPZ. This peculiar stress distribution was called physically verisimilar stress (PVS), and it was accepted as the basis of the proposed PVS model, which used three material parameters: maximum stress, intrastructural linear size a, and dimensionless value n, taking into account the plastic properties of the material. The relationships for determining the PVS model parameters were suggested for concrete. Strength problems were solved by the modified method of sections, in which the PVS was applied along the FPZ. The FM model based on PVS and the modified method of sections led to an acceptable in-practice method of strength design, which was considerably simpler than the known phase-field method. The proposed PVS model and design method allow for the prediction of the cracks development, considering their stable growth up to the critical (ultimate) values of the crack length and load. The unstable cracks propagation is considered also. The paper provides examples of designs and shows sufficient theoretical strength relative to the experimental one.