The work is concerned with an analytical investigation of the behaviour of reinforced-concrete beam-column joint sub-assemblages under monotonic and cyclic loading in an attempt to assess the effect of cracking suffered by the joint on the overall structural response. The behaviour of the structural forms investigated was established by nonlinear three-dimensional finite-element analysis, after the latter had first been validated through a comparison of analytical predictions with published experimental findings. In all case studies presented, the joints were
found to suffer considerable cracking that initiated at early load stages and led to an increase of the overall displacement values by a factor larger than 2. Such behaviour indicates that the assumption of 'rigid joint', which is implicit in methods used for the practical analysis of frames, is not applicable when such methods are employed for the analysis of concrete structures, even within the elastic range of structural behaviour.
Demetrios M. Cotsovos, DiplEng, MSc, DIC, PhD, CEng
Concept Engineering Consultants, London, UK
Michael D. Kotsovos, DiplEng, DIC, PhD, DSc, CEng
Laboratory of Concrete Structures, National Technical University of Athens, Greece