Abstract:
The beam column connection is the most critical zone in a reinforced concrete frame. The
strength of connection affects the overall behavior and performance of RC framed structures
subjected to lateral load and axial loads. Beam column connection may be subjected to large
seismic lateral loading and severe ground shaking during earth quakes. The study of critical
parameters that affects the overall joint performances and response of the structure is important.
Recent developments in computer technology have made possible the use of Finite element
method for 3D modeling and analysis of reinforced concrete structures. Nonlinear finite element
analysis of reinforced concrete beam column connections subjected to lateral loading was
performed in order to investigate joint shear failure mode in terms of joint shear capacity,
deformations and cracking pattern using ABAQUS software. A 3D solid shape model using 3D
stress hexahedral element type (C3D8R) was implemented to simulate concrete behavior. Wire
shape model with truss shape elements (T3D2) was used to simulate reinforcement’s behavior.
The concrete and reinforcement bars were coupled using the embedded modeling technique. In
order to define nonlinear behavior of concrete material, the concrete damage plasticity (CDP)
was applied to the numerical model as a distributed plasticity over the whole geometry. The
study was to investigate the most influential parameters affecting joint shear failure due to
column axial load, beam longitudinal reinforcement ratio, joint panel geometry and concrete
compressive strength.
The Finite Element Model (FEM) was verified against experimental tests of two non-ductile
exterior and interior RC beam column connection subjected to lateral loading. The model
showed good comparison with test results in terms of load-displacement relation, cracking
pattern and joint shear failure modes. At yielding of reinforcement and initiation of concrete
crushing, the increase in concrete compressive strength influences the overall joint shear stress strain behavior. Other parameters such as column axial load, beam longitudinal reinforcement
ratio, and joint panel geometry did not show a distinct and significant effect that can predict the
failure. The FEA clarified that the main influential parameter for predicting joint shear failure
was concrete compressive strength.
