3d Detailed Modeling of Reinforced Concrete Frames Considering Accumulated Damage During Static Cyclic and Dynamic Analysis – New Validation Case Studies

Abstract

The study of the hysteretic behavior of reinforced concrete members that undergo static cyclic and dynamic loading conditions in cases where the loading level is close to their carrying capacity, is a challenging open research subject, which currently is being investigated by many researchers. The development of an objective and robust 3D constitutive modeling approach that will be able to account for the accumulated material damage and stiffness deterioration is of great importance in order to realistically describe the physical failure mechanisms thus numerically study the seismic performance of RC structures. The adopted concrete material model in this research work is based on the material model proposed by Markou and Papadrakakis, which was an extension of the Kotsovos and Pavlovic work. Furthermore, the use of two newly proposed damage factors that are computed through the use of the number of opening and closing of cracks during the nonlinear cyclic analysis, are further investigated and their ability in capturing the accumulated material damage in both steel and concrete is further discussed in this research work. The numerical accuracy of the proposed method is validated by comparing the numerical results with the experimental data of two beam-column frame joints, a shear wall and a threestorey three-bay RC frame. According to the experimental setups, the RC joint and the shear wall specimens were tested under ultimate limit state cyclic loading, whereas the RC frame was tested under dynamic loading conditions. Based on the numerical findings, the proposed algorithm manages to capture the experimental results in an accurate manner and the numerical response of the understudy algorithmic implementation was found to exhibit computational robustness and efficiency.

Finite element modelling of plain and reinforced concrete specimens with the Kotsovos and Pavlovic material model, smeared crack approach and fine meshes

“…Conclusively, the mesh size misconception is not valid in this case, thus the authors strongly believe that this research work is a proof that the under study material model performs numerically well when combined with the finite element method and in a similar manner with any other constitutive material model currently available in the international literature. With the only difference, that it outperforms them when used with coarser meshes (AlHamaydeh et al, 2017;Engen et al, 2017;Gravett et al, 2019;Markou, 2013Markou, , 2015Markou, , 2018Markou and AlHamaydeh, 2018;Markou and Genco, 2019;Papadrakakis, 2013, 2015;Markou et al, , 2017Markou et al, , 2018aMarkou et al, , 2018bMarkou et al, , 2019aMarkou et al, , 2019bMourlas et al, 2016Mourlas et al, , 2017aMourlas et al, , 2017bMourlas et al, , 2017cMourlas et al, , 2018Mourlas et al, , 2019aMourlas et al, , 2019bMourlas et al, , 2019cSaadi et al, 2018). laboratory technicians of the Civil Engineering Department of the University of Pretoria, during the experimental campaign that was performed during this research work.…”

“…Further development and use of the 3 D detailed modeling approach was presented in AlHamaydeh et al (2017); Gravett et al (2019); Markou (2015Markou ( , 2018; Markou and Genco (2019); Markou and Papadrakakis (2015); Markou et al ( , 2017Markou et al ( , 2018aMarkou et al ( , 2018bMarkou et al ( , 2019aMarkou et al ( , 2019b; Mourlas et al (2016Mourlas et al ( , 2017aMourlas et al ( , 2017bMourlas et al ( , 2017cMourlas et al ( , 2018Mourlas et al ( , 2019aMourlas et al ( , 2019bMourlas et al ( , 2019c; Saadi et al, (2018), where the adoption of relatively large hexahedral elements was assumed. This assumption was solely based on computational restrictions and was not related to the fact that the proposed method was not suitable when finer meshes were used.…”

State-of-the-art investigation of wind turbine structures founded on soft clay by considering the soil-foundation-structure interaction phenomenon – Optimization of battered RC piles

“…It must be noted here that, the developed modal algorithm incorporated in ReConAn FEA [35] and its ability to accurately predict the fundamental modes of RC structures was validated through the use of experimental data found in the international literature, whereas the validation was published in [28,29,30,23]. Gravett et al [24] used the developed algorithm in the study of 2-,4-,6-,8-,10-and 20-storeys RC buildings and their dynamic response, while the algorithm was also recently used for the investigation of the SSI phenomenon and its effect on the fundamental period of multi-storey RC structures [6].…”

Development of a New Fundamental Period Formula by Considering Soil-Structure Interaction With the Use of Machine Learning Algorithms

“…During a seismic excitation, the interaction between the superstructure (building) and the substructure (soil) can become important as it starts to affect the stress-strain distribution within the superstructure, altering the initial expected results [1][2][3]. In general, it has been found that soil-structure interaction (SSI) can increase the fundamental period and the overall damping of the system, thus it is important to consider it in order to eliminate unsafe designs and unexpected damage development [4][5] during an earthquake excitation.…”