Keywords: beam–column joints, numerical simulation, ANSYS, FRP, retrofitted joints, flexure, shear, size effect, Baž, ant, size effect law, strong–column weak–beam, reinforced concrete, material behaviour, earthquakes, fibre reinforced composites, failure stresses, finite element method, FEM
Studies on size effect of RC and retrofitted beam–column joints using numerical approach
Available theories of material behaviour that predict size effects are receiving increasing attention in the technical literature nowadays. Beam–column joint is one of the vital elements, whose behaviour during earthquake is very critical. No numerical study has been done to establish the existence of size effect on beam–column joint. Hence, in the present study, a numerical exercise has been taken by considering four types of beam–column joints covering two reinforced concrete with some specific deficiencies and another two as retrofitted with fibre reinforced composites. Further, three different sizes of specimens have been considered in each of the types for the evaluation of existence of size effect in beam–column joints. The numerical studies have been carried out using the general purpose finite element software ANSYS. The numerical study has simulated the behaviour of field reinforced concrete and retrofitted specimens quite accurately. For each analysed case study, the ultimate failure stresses were evaluated and the bi–logarithmic plot was developed, this confirming the presence of size effect as previously proposed by Bažant.