Numerical modeling of the cyclic behavior of reinforced concrete chimney sections

Abstract

The capability of numerical models to predict the behavior of reinforced concrete structures depends on the quality of the model, which is related to many parameters such as the definition of boundary conditions and loading, mesh quality, element formulation, material models. In this thesis, the cyclic behavior of two reinforced concrete chimney sections was numerically investigated. One of the chimney sections was oriented to be bending critical, and the other was oriented to be shear critical. Thus, major failure modes of reinforced concrete, exural and shear, were evaluated. The performance of 4 different concrete material models in LS-DYNA, MAT 072R3 K&C, MAT 084 Winfrith, MAT 159 CSC, MAT 272 RHT, was studied. The input parameters of MAT 084, such as strain rate parameter types and values, compressive strength, tensile strength, aggregate size, and tangent modulus, were studied in detail. Other material models were used with a minimum number of inputs. The effect of material properties of the rebar was also considered. To benchmark the simulation results, the analysis results were compared with previously conducted experiments in terms of peak load, initial stiffness of load-displacement curves, the shape of hysteresis loops, pinching behavior, and stiffness degradation. The results demonstrate that the only model which shows good agreement with the experimental results is the model with the Winfrith concrete model.