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On the seismic protection of free-standing art objects by base isolation technique: A case study
Published in Renato Lancellotta, Carlo Viggiani, Alessandro Flora, Filomena de Silva, Lucia Mele, Geotechnical Engineering for the Preservation of Monuments and Historic Sites III, 2022
Davide Pellecchia, Nicolò Vaiana, Salvatore Sessa, Luciano Rosati
The behaviour of the helical WRIs is modelled by using an efficient uniaxial phenomenological model (Vaiana et al. 2018, 2021b, 2021c). Such a hysteretic model was chosen because of some benefits, including a clear mechanical meaning of the costitutive parameters and its fast computation of the device restoring force. Moreover, the algebraic nature of the model allows one to obtain the dissipated energy by a closed-form solution (Pellecchia et al. 2021) which turns out to fulfil the Drucker's postulate for the considered application (Sessa 2021). The hysteretic model parameters are computed by experimental loops using a user-friendly program named Parameter Identificator (ParIde) based on the algorithm described in Sessa et al. (2020).
SUBSTRUCTURED COMPUTER-ACTUATOR HYBRID ANALYSIS FOR INELASTIC EARTHQUAKE RESPONSE OF STRUCTURES
Published in Franklin Y. Cheng, FU Zizhi, Computational Mechanics in Structural Engineering, 2003
Yoshikazu YAMADA, Hirokazu IEMURA, William TANZO
In the present implementation, a structure is discretized into lumped-parameter system model and analytical members are described by member models (e.g., single-component member models). A wide variety of hysteretic models are available such as bilinear models and some degrading models (e.g., Takeda model for RC). In this present work on the steel columns, the analytical values of the yielding girders are varied to simulate strong-column weak-girder models and weak-column strong-girder models in which the inelastic response behavior of the critical first-story columns are investigated.
Hysteretic Model of Reinforced Concrete (RC) Bridge Columns in Saline Soil Environment
Published in Journal of Earthquake Engineering, 2020
Jianjun Zhao, Changwang Yan, Shuguang Liu, Ju Zhang, Shuang Li
Li, Zhou, and Zheng (2013) established the hysteretic model of corroded RC columns, which can reflect the degradation of strength and stiffness, by using the trilinear model. The results show that the model can reflect the hysteretic model of corroded RC columns well. Chen, Niu, and Wang (2005) based on the trilinear model, the calculation expression for determining the restoring force model of corroded reinforced concrete flexural members is proposed. Dai, Yu, and Lu (2020) collected 77 corroded rectangular reinforced concrete columns, and established a polygonal hysteretic model considering stiffness and strength degradation. The developed hysteretic model together with the predictive equations for the model parameters are proved of high accuracy through comparison with the test results. However, the research on hysteretic curve model of corroded structure or component is not perfect.
Seismic Evaluation of Tall Buildings Using a Simplified but Accurate Analysis Procedure
Published in Journal of Earthquake Engineering, 2018
Tahir Mehmood, Pennung Warnitchai, Phichaya Suwansaya
Under this circumstance, it is possible to check how the accuracy of the UMRHA procedure will be affected if an incorrect modal hysteretic model is adopted. This is achieved by simply replacing the flag-shaped model of the first mode with other models, while assuming that the second and third modes remain elastic. Three different hysteretic models are considered for this purpose: bilinear 01, bilinear 02, and linear models. The bilinear 01 is a bilinear hysteretic model of which the envelope is fitted to the monotonic pushover curve in a conventional manner, as shown in Fig. 8a. By this model, the elastic stiffness (Ki) is slightly lower than the initial uncracked stiffness of the structure, the post-elastic stiffness is about 8% of the elastic one (α = 0.08), and the yield displacement at the roof level is about 0.6% of the building’s height. Hence, for roof drift ratio lower than 0.6%, which is likely the case here, the first mode will respond like a linear SDOF system with a slightly longer natural period than that of the uncracked building. The bilinear hysteretic loops may not be formed. Therefore, another bilinear model—bilinear 02—is also considered. The bilinear envelope of this model is set such that its elastic stiffness (Ki) matches with the initial uncracked stiffness of the structure, and the post-elastic stiffness approximately fits with the monotonic pushover curve as shown in Fig. 8b. By this way, the roof drift ratio at yielding is about 0.25%, which is unrealistically low, but the bilinear hysteretic loops will definitely be formed. The third model is simply a linear model, with the elastic stiffness (Ki) set equal to the initial uncracked stiffness of the structure, as shown in Fig. 8c. It must be noted here that none of these three models can accurately represent the hysteretic behavior of the first mode, but the original flag-shaped model does.