tesi A. Caggiano.pdf - EleA@UniSA - Università degli Studi di Salerno

Chapter 7. Cracked hinge numerical model for fiber-reinforced concretethe well-known Winkler beam theory is used to describe the dowel force-displacementrelationship, which is transformed in terms of dowel stress vs. relative displacements[ ]suitable for the cracked hinge model (namely τ f uT,cr of Eq. 7.2). On the other hand,the empirical model reported by Dulacska [1972] for RC-structures is taken as maximumdowel strength. The complete model for the dowel formulation has completely beenreported in Chapter 3.7.4 Numerical predictionsThe composite model outlined in the previous sections is introduced in the crackedhinge zone with the aim to simulate the 150 × 150 × 600 mm 3 notched concrete specimens,tested under four-point bending presented in Chapter 2.For the purpose of the numerical evaluations, three material types are considered:• plain concrete,• steel fiber-reinforced concrete having ρ f = 0.5% and,• steel fiber-reinforced concrete with ρ f = 1.0%.The geometry and material properties are chosen according to the tests outlined inexperimental campaign described in Chapter 2.vertical load kN 3530252015105L100Numerical predictionsρ f 1.0ρ f 0.500 1 2 3 4 5 6CTODm mmFigure 7.5: Load-C T ODm numerical predictions against the experimental data on SFRCL100-type by Caggiano et al. [2012a].148