The accuracy of the lumped plasticity model for estimating nonlinear behavior of reinforced concrete frames under gradually increasing vertical loads

Abstract

Simplicity and computational efficiency of the lumped plasticity model have made it a popular approach for analyzing structures. However, it has been shown by researchers that the accuracy of the lumped plasticity model for representing the inelastic behavior of reinforced concrete (RC) structures needs further investigations. Two full‐scale RC frames with different shear spans were constructed and subjected to the vertical load through their beam. Finite element (FE) models of the tested specimens were established in SAP2000 software, and their results were compared with the experimental tests. The effects of using different plastic hinge lengths, initial effective stiffness, and locations of plastic hinges were investigated. It was observed that regardless of the selected plastic hinge lengths, the established FE models estimated the yield and ultimate loads of the frames accurately. However, they did not estimate accurately the vertical displacements corresponding to the yield and ultimate loads. Results also indicated that the obtained yield and ultimate loads from the established FE models were significantly influenced by the selected locations for plastic hinges. Moreover, at the ultimate load of frames the estimated damage level to the mid‐span of beams by FE models was lower than the results of experimental tests.

Seismic Fragility Curves for Tall Concrete Wall Building in Malaysia Subjected to Near-Field Earthquakes

“…The fiber element method has been successfully used for estimating the inelastic behavior of concrete shear walls by previous researchers [24][25][26][27]. The nonlinear response of beams and columns were simulated by the lumped plasticity model [28]. Plastic hinges were assigned to both ends of beams and columns.…”

A new Distinct Element meso‐model for simulating the rocking‐dominated seismic response of RC columns

“…7 The numerical assessment of the seismic response of RC columns is typically conducted using simplified modeling techniques, including Finite Element (FE) models 8,9 and sectional analysis tools. 10,11 Lumped plasticity models, where the inelastic behavior of structural elements is simulated by plastic hinges that are assigned to critical locations, 12 have been extensively used because of the reduced analysis time required, and adequate results were obtained when simulating both quasi-static 13,14 and dynamic 15,16 rocking responses of RC columns of varying dimensions and detailing. As discussed in Kenawi et al ( 2008), 17 however, the a priori definition of plastic hinges in these models often prevents the realistic simulation of damage initiation and propagation, while also making the evaluation of axial force-bending moment interaction effects dependent upon iterative calibration procedures not necessarily valid for different axial load levels and moment gradients.…”

Effectiveness of ACI-318 and TS-500 Codes on Nonlinear Seismic Analysis of RC structures: Force-Based Approach

“…The Distributed plasticity model is based on the assumption that the deformations have occurred throughout an RC structural element. Although the model requires more effort for numerical calculations, it is preferred in most design codes due to its accuracy in the solutions depending on the development of computer technology (Lu et al 2013;Vafaei et al 2020). Therefore, an investigation of the model's effectiveness is required for different design codes.…”