Title: Failure Mode Transitions in Reinforced Concrete Beams—Part 1: Theoretical Model

Author(s): Alberto Carpinteri, Jacinto Ruiz Carmona, and Giulio Ventura

Publication: Structural Journal

Volume: 108

Issue: 3

Appears on pages(s): 277-285

Keywords: failure; scale; shear

DOI: 10.14359/51682343

Date: 5/1/2011

Abstract:
The bridged crack model is an efficient theoretical and numerical tool for investigating the behavior of structural reinforced concrete (RC) elements in bending. The model is based on linear elastic fracture mechanics concepts and equilibrium and compatibility equations are applied to a Mode I cracked beam segment. The model is herein extended to include both compression crushing and shear cracking, assuming a shape for the hypothetical crack trajectory and determining the shear crack initiation point and the load versus crack depth propagation curve. In this paper, the three collapse mechanisms—flexure, shear, and crushing—are considered jointly, so that failure modes can be immediately compared to detect which one dominates and the related failure load. Consequently, the model predicts all the mutual transitions between the different mechanisms, and these transitions are shown by varying the governing nondimensional parameters. A global transition scheme is introduced for illustrating the relevant size/scale effects.