Mechanical Engineering and Materials Science
Date of Award
Master of Arts (MA)
Chair and Committee
There are a multitude of existing material models for the finite element analysis of cracked reinforced concrete that provide reduced shear stiffness but do not limit shear strength. In addition typical models are not based on the actual physical behavior of shear transfer across cracks by shear friction recognized in the ACI Building Code and present in previous experimental work. Recently a shear friction model was proposed that was able to capture the recognized cracked concrete behavior by limiting the shear strength as a function of yielding in the reinforcement across the crack. However, the proposed model was only formulated for the specific case of one-directional cracking parallel to the applied shear force. The goal of this research is to update and generalize this proposed shear friction model for finite element use. In order to generalize the theory, the shear friction model was expanded to two-directional cracking at any orientation. This expansion is necessary for handling the analysis of complex structures and non-proportional loading cases present in real design and testing situations. This generalized model was formulated as a total strain based model using the approximation that crack strains are equal to total strains and later reformulated to separate crack strains from total strains to improve the overall modelΓÇÖs accuracy. In addition, various loading programs and convergence methods were tested in an attempt to achieve full cyclical convergence. Finally this research provides comparative studies of the generalized shear friction model and other existing models for a loading case and crack orientation similar to that of a shear wall. Inconsistencies in predicted stresses, displacements and material interactions show the necessity for further testing and analysis to determine the actual behavior for this seemingly important case.
Mitchell, Jeffrey, "Two-Direction Cracking Shear-Friction Membrane Model for Finite Elment Analysis of Reinforced concrete" (2010). All Theses and Dissertations (ETDs). 466.