Modeling of interior beam-column joints for nonlinear analysis of reinforced concrete frames

Abstract

Beam-column connections are often assumed rigid in traditional frame analysis, yet they undergo significant shear deformations and greatly contribute to story drifts during earthquake loading. Although local joint models are available in the literature for the investigation of single, isolated joints, there is a lack of holistic frame analysis procedures simulating the joint behavior in addition to important global failure modes such as beam shear, column shear, column axial, and soft story failures. The objective of this study is to capture the impact of local joint deformations on the global frame response in a holistic analysis by implementing a joint model into a previously-developed global frame analysis procedure. The implemented joint element simulates joint shear deformations and bar-slip effects. Concrete confinement effects are also considered so that both older and new joints can be modeled. The developed procedure provides better overall load-deflection response predictions including the local joint response.

Numerical study based on the Constitutive Relation Error for identifying semi-rigid joint parameters between planar structural elements

“…Now, it comes a crucial question: considering planar structural elements, is there an universal model to be used? In the literature, there seems to be no unanimous answer to this question [12]. In this case, there are two immediate alternatives to approach it: deriving a new model that respects the physical principles of Mechanics and reflects the observations, or, choosing a consecrated, although limited, model and adjusting its parameters to correspond some observed data sets.…”

Numerical Simulation on Seismic Behavior of Steel Fiber Reinforced Concrete Beam—Column Joints

“…The "super-node" element model proposed by Lowes et al [10] and Mitra et al [11] has comprehensive consideration factors, a reasonable mechanical model, and moderate calculation amount of numerical simulation, and can be used to simulate local inelastic deformation of nodes [12][13][14][15][16][17][18]. The "super-node" element model has been incorporated into the "Opensees" [19] structural analysis platform, which is called a beam-column joint element (BCJE) model.…”

Simplified assessment of the need for the explicit model of RC beam‐column joints instead of the rigid model

“…Reinforced concrete beam‐column (RCBC) joints are structural elements whose primary function is to interconnect the adjacent beams and columns. The failure of RCBC joints (i) may lead to an unexpected overall failure mechanism of the structure, (ii) is sometimes brittle, and (iii) can drastically limit the structure load capacity if it precedes the failure of the adjacent elements ( partial strength joints ) . Consequently, current technical specifications require that the strength of RCBC joints is larger than that of the adjacent columns and beams ( full strength joints ), that is , a joint must not fail before its adjacent elements—in seismic design this is accomplished through the capacity design principles , which classify RCBC joints as brittle components …”

“…The failure of RCBC joints (i) may lead to an unexpected overall failure mechanism of the structure, (ii) is sometimes brittle, and (iii) can drastically limit the structure load capacity if it precedes the failure of the adjacent elements (partial strength joints). [1][2][3][4] Consequently, current technical specifications require that the strength of RCBC joints is larger than that of the adjacent columns and beams (full strength joints), that is, a joint must not fail before its adjacent elements 5 -in seismic design this is accomplished through the capacity design principles, which classify RCBC joints as brittle components. [6][7][8] However, regardless of the full or partial strength nature of RCBC joints, the influence of their flexibility on the structure overall quasi-static behaviour should not be neglected 9 -not to mention their influence on progressive collapse 10,11 or seismic behaviour, [12][13][14] which are beyond the scope of this paper.…”