TA653 : Evaluating the efficiency of supplementary rebar system in improving hysteretic damping of self-centering rocking walls
Thesis > Central Library of Shahrood University > Civil & Architectural Engineering > PhD > 2022
Authors:
[Author], Farshid Jandaghi Alaee[Supervisor], [Supervisor], [Advisor]
Abstarct: Although self-centering rocking walls have shown the acceptable performance, in terms of decreasing downtime, repair cost, and providing continuous serviceability, their energy-dissipation capacity is relatively low. In this research, therefore, a supplementary rebar system (SRS) is introduced to improve this drawback. The applicability, simplicity of the installation and replacement of this system after yielding/failure, and its high efficiency are among the advantages of it. The efficiency of this system and its seismic performance were assessed by conducting a parametric numerical study using validated finite element models in two parts, static and dynamic nonlinear analyses, and considering the cross-sectional area, number, and location of the proposed system as the study variables. The increase in energy-dissipation capacity and the equivalent viscous damping (up to 17.36%) show the efficiency of SRS in improving the hysteresis damping of the studied walls. The performance evaluation results obtained from IDA analyses show that self-centering rocking walls with SRS have sufficient safety against MCE earthquakes. This study proposed an analytical method to predict the hysteresis behavior of hybrid rocking walls (HRWs) in the two limit states of decompression and geometric nonlinearity. The flag-shaped curve of a HRW under a given cyclic load was described using the parameters of initial stiffness, post-yield stiffness, and the dissipated energy by the wall energy dissipaters. In this method, the hysteresis loops of the wall were determined assuming no tendon yielding and concrete crushing at the wall toes. The results of the proposed analytical method were validated with the results of tests on two HRWs under cyclic loads and validated finite element models. Comparing the results of the analytical method with those of the tests and numerical models showed that the proposed method can provide acceptable predictions for the yield point, ultimate point, initial and post-yield stiffnesses, energy-dissipation level in each loading cycle, as well as the hysteresis behavior of hybrid walls. This showed the efficiency and accuracy of the proposed analytical method.
Keywords:
#Keywords: Self-centering Rocking Walls #Supplementary Rebar System #Hysteretic Damping #Nonlinear Modeling #Incremental Dynamic Analysis #Hysteretic loops #Analytical Method. Keeping place: Central Library of Shahrood University
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