Reinforced Concrete Beam-Column Inverted Knee Joint Behaviour after Ground Corner Column Loss-Numerical Analysis

Abstract

Beam-column joints are critical component in the load path of reinforced concrete (RC) frames, due to their role in transferring loads among different RC frame components. The loss of a ground corner column in a RC frame turns an exterior joint into an inverted knee joint and recent code provisions for exterior joints are not sufficient to knee joints because of reinforcement defects in terms of joint vertical stirrups and improper column bar anchorage. This paper investigates numerically the behaviour of these joints under a closing moment using nonlinear finite element (FE) analysis with LS-DYNA. Beam's bar anchorage type and joint vertical stirrups are the main parameters considered next to concrete compressive strength, longitudinal reinforcement ratio and lateral beam effect. This study indicates that, anchorage beam's bar with U shaped produces better behaviour than 90° standard hooks or headed ends. Contribution of joint vertical stirrups is more influential with headed bars anchorage. Increasing concrete compressive strength and beam reinforcement ratio improve joint ultimate capacity. The presence of lateral beams reduces the rate of concrete degradation in the joint after reaching ultimate capacity and increases joint carrying capacity.

Comparison of Seismic Response Corner Beam-Column Joint with and without Fuse Bars Under In-Plane Lateral Cyclic Loading

“…It can be concluded that the ultimate strength capacity of corner beam-column joint with fuse bars has three times higher than corner joint without fuse bars. The main reason is because CJ-2B Specimen has more percentage of reinforcement bars in the joint as compared to BC1-2C Specimen supported the study conducted by other researchers [22].…”

Progressive collapse of reinforced concrete buildings considering flexure-axial-shear interaction in plastic hinges

“…It was observed that although the total applied load in the first and the second stages of loading was significantly improved (from 8.2% to 41.2% and 22.5% to 45.9%), there was no significant increase in the final collapse load. Helmy et al (2012) and Abdelwahed et al (2018) rightly pointed out to adopt innovative solutions for improving progressive collapse resistance for the case of corner column loss. This…”

FE Modeling and Seismic Performance Evaluation of Hybrid SMA-Steel RC Beam-Column Joints

“…In the finite element modeling, accurate meshing is an important factor in achieving more accurate results. Therefore, a mesh sensitivity analysis should be performed to select an adequate mesh size and to approximately avoid mesh-dependency (Abdelwahed et al 2018;Najafgholipour et al 2017;Sanabria Diaz et al 2018). Indeed, it is to be investigated that the mesh size dependency does not significantly affect the overall response of the numerical models.…”