Abstract
In this doctoral dissertation, a simple yet accurate finite element model is developed for the seismic inelastic behavior of composite columns based on concentrated plasticity modeling. This model can be used for seismic analysis of composite moment resistance frames. In the past, similar models have been widely used to describe the structural response, using the well-known Ramberg-Osgood and Al-Bermani models. Initially, the main scope is to determine the appropriate parameters of the Ramberg-Osgood hysteretic model, available in Ruaumoko program, so that it is able to accurately simulate the composite behavior of a composite member under monotonic and cyclic loading. The hysteresis model parameters under consideration have been determined on the basis of an extensive database of responses derived from the determination of the cyclic response of numerous composite columns with the aid of ATENA program and the use of advanced finite element models for both concrete and steel. The accuracy of these advanced finite element models is confirmed by comparing their results with those of the composite-column experiments under well-known cyclic bending load protocols with variable intensity and constant axial load. Furthermore, numerous framed structures, which consist of circular concrete filled-steel tube columns and composite beams, have been analyzed and designed SAP2000 program. Additionally, these frames have been examined under strong seismic records using Ruaumoko program. Based on these analyzes, empirical equations are developed that can determine or predict the damage of a frame under seismic excitation. Additinally, a composite inshore structure is investigated taking into account the soil-structure interaction and compared this with the response of a similar inshore structure made of reinforced concrete. Finally, the effects of multiple earthquakes on composite buildings as well as the effects of incident angle of seismic waves are investigated.
Advisory committee
Supervisor: Hatzigeorgiou George, Associate Professor HOU.
Karampalis Dimitris, Professor, University of Patras.
Bousias Stathis, Professor, University of Patras.