Deflection estimate of reinforced concrete beams by the lumped damage mechanics

Estimativa de flecha em vigas de concreto armado pela mecânica do dano concentrado

Abstract

The evaluation of the deflection in beams is an indispensable step of the structural design. Currently, many standard codes adopt the Branson’s model. However, the Branson’s model underestimates the deflection of beams with a reinforcement rate of less than 1%. Therefore, this study proposes a new alternative to quantify the deflections in reinforced concrete beams, based on the Lumped Damage Mechanics (LDM). LDM is a nonlinear theory, which uses concepts from Fracture and Damage Mechanics combined with plastic hinges. The viability of the proposed model was verified through comparisons with results from experimental works developed by other authors and the application of the Branson’s model. The obtained results showed that the proposed calculation model had a good approximation of the experimental data with satisfactory accuracy and equivalent values to the Branson’s model in the investigated scenarios.

Keywords:
reinforced concrete beams; deflection; lumped damage mechanics; plastic hinge; structural design