Structural Response Comparison in the Case of Reinforced Concrete Frames

摘要

Ductile structural elements present an important plastic deformation capacity, unlike brittle elements that should be avoided at all times. The plastic deformations occur usually in certain limited areas in a structure, known as plastic joints. The nonlinear modelling of the composite material know as steel reinforced concrete represents one of this study`s main objectives. Nonlinear modelling solutions for steel as well as for concrete are presented in the second section. The implied comparisons in the first stage of the study suggest the effect of introducing the steel reinforcements in the analysis (Fig. 1 b). In the second case study an advanced analysis (time integration) is used, from which one can follow the loads in the concrete as well as in the steel for an accelerogram scaled for the Constan?a area. In the third case study the degradation of the concrete and flowing of the steel reinforcements, if that is the case, by reaching the maximum load bearing is underlined. Evidently, the subjects of the case study are the plastic areas at the end of the beams and bottom of the pillars marked in Fig. 1 a. Besides the comparative analysis through the diversity of the accepted calculation methods, this paper proposes to determine the state of strain in the concrete as well as in the steel reinforcements, analysing the co-operation between these two materials. In this respect, different finite elements shall be used for the concrete, compressed steel, and stretched steel, considering the co-operation between them.