VASSILIOS J. SOULIS (1), GEORGE C. MANOS (2)
(1) Lecturer, Department of Civil Engineering Educators, School of Pedagogical and Technological Education, Athens, 15124, Greece vassilios_soulis@yahoo.com
(2) Emeritus Professor, Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54636, Greece, gcmanos@civil.auth.gr
ABSTRACT
In this paper different modelling techniques for the simulation of masonry infill panels inside R/C frame structures are investigated in an effort to develop a model that can capture the non-linear behavior of masonry infilled R/C frames when infill panels of different technical characteristics, configurations and details are adopted. Two types of numerical simulation techniques for the masonry infills are adopted, namely a macro-modelling technique and simulation where the masonry infill and the joint interface between the surrounding frame and the infill is represented by a diagonal strut model. And, inelastic finite element simulations are employed, including stiffness and strength degradation. This is done by simulating the inelastic behavior of the masonry infill, the formation of plastic hinges for the R/C frame at pre-defined locations and the sliding or separation of the masonry infill from the surrounding R/C frame. The paper then deals with the applicability of this hopefully “successful” non-linear masonry-infill concrete-frame numerical simulation to predict realistically the in-plane seismic behavior of prototype multi-storey R/C structural frame formations with masonry infills. In order to overcome the computational time and memory requirements, use was made of an equivalent post-elastic “pushover” type of analysis that draws information from the stiffness and strength variation from multi-bay, one-stoery R/C masonry infilled unit frames that compose a given multi-storey structural formation. In doing so, the fully non-linear numerical simulation of the single-storey, multi-bay units, that compose this structural formation, presented, is utilized. In what follows, it is shown that the proposed “equivalent pushover analysis” is successful in predicting reasonably well the “top storey versus base shear” response of a 6-storey structure and the formation of failures along the masonry infill walls of the same structure.