Reinforced Concrete 3-D Beam-to-Column Joints Subjected to Cyclic Seismic-Type Loading. Laboratory Measurements and Numerical Simulations

Abstract

These numerical simulations employed all the geometric and mechanical characteristics of the tested specimen. In all these specimens the reinforcing details prohibited the appearance of shear failure modes. Therefore, this study focuses on the flexural response and the numerical simulation of the bending mode of failure at either the columns or the beams forming each sub-assembly. Towards this objective the features of commercial software were utilized. The observed behaviour is portrayed in terms of horizontal load versus horizontal displacement cyclic response as well as bending moment cyclic response that develops et the beams and columns forming this RC joint. These bending moment values are compared with the corresponding ultimate bending moment values derived from the relevant cross-sectional detailing as well as from the measured concrete and steel material properties. From this comparison the observed cracking of the beams near the RC joint can be explained. The used 2-D and 3-D numerical simulations of the tested RC joint were successful up to a point to represent the observed flexural non-linear response of this RC structural sub-assembly. The used 3-D numerical simulation, although more complex than the corresponding 2-D numerical simulation, produces numerical predictions that are in better agreement with the observed maximum horizontal load and therefore ultimate bending moment capacity. By comparing the numerical results with the corresponding experimental measurements the validity of the employed numerical simulation is validated. 225 COMPDYN 2019 7 th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, M. Fragiadakis (eds.

Numerical Investigation of R/C Columns Before and After FRP Strengthening Under Seismic Type Loadings Utilizing a Novel Anchoring System

“…The FRP mechanical properties were derived by material testing [9], while the interface behavior was calibrated according to available information over the literature [2,6]. The validation of the numerical methodology used here is verified by a number of other publications [2,5,6,10]. Thus, the numerical predictions discussed below can be considered realistic up to a point.…”

“…Katakalos et al [4] investigated cantilever Tshaped RC beams strengthened with steel fibre reinforced polymer concluding that the anchoring system has a significantly more pronounced effect on the performance of the beams and the mode of failure than the type or spacing of the strips. The investigation of a 3D RC joint under seismic loads is investigated by Melidis et al [5,6]. To ensure the effectiveness of the FRP flexural strengthened beams and columns an anchoring system using steel sections near the joint core region was employed.…”

Experimental and Numerical Investigation of FRP Strengthened R/C Beam-to-Column Joints Subjected to Cyclic Seismic-Type Loading

“…For this purpose, a 1:3 scaled 3-D reinforced concrete (RC) joint specimen was constructed and tested at the laboratory of Strength of Materials and Structures of Aristotle University ( [4], [5], [6]. [10], [11]), shown in figure 1. The experimental campaign included testing of the joint specimen at 3 stages.…”