An equivalent SDOF system model for estimating the response of R/C building structures with proportional hysteretic dampers subjected to earthquake motions

2010 ◽  
Vol 40 (5) ◽  
pp. 571-589 ◽  
Author(s):  
Juan Andrés Oviedo A. ◽  
Mitsumasa Midorikawa ◽  
Tetsuhiro Asari
Keyword(s):  
System Model ◽  
Building Structures ◽  
Sdof System ◽  
Equivalent Sdof System ◽  
Hysteretic Dampers

Analysis of MDOF Pseudo-Dynamic Test Design of High Flexible Structure

2014 ◽  
Vol 638-640 ◽  
pp. 1781-1784
Author(s):  
Hong Biao Liu ◽  
Qiang Zhang ◽  
Xian Peng Liu
Keyword(s):  
Numerical Simulation ◽  
Dynamic Test ◽  
High Mode ◽  
Flexible Structure ◽  
Test Design ◽  
Base Shear ◽  
Sdof System ◽  
High Rise ◽  
Equivalent Sdof System ◽  
The Impact

In order to point out the main factors in MDOF pseudo-dynamic test design of high-rise flexible, the key points in pseudo-dynamic test design using equivalent MDOF system were analyzed based on the theoretic derivation and numerical simulation, and the problems to notice in test design were pointed out, the pseudo-dynamic test results validity of high piers based on equivalent SDOF system was discussed, and the impact of high mode to the earthquake response of high-rise flexible structure was acquired. The results of numerical simulation of lumped-mass model prove that the contribution of high mode to the displacement of high flexible structure is little, and the displacement is mainly provided by the first-order mode, which is nothing to do with the selection of seismic waves. However, the high mode have great influence on seismic base shear and base moment of high flexible structure, and the influence level is associated with the properties of seismic wave spectrum. Under one specific earthquake wave, the second-order vibration may play a main contribution to seismic base shear and base moment of high-rise flexible structure. Therefore, it is proper to use equivalent two-degree of freedom system in pseudo-dynamic test of high piers. However, if using equivalent SDOF system, the structural displacement response is correct while the strain data and experimental phenomenon may be untrue. The conclusion proposed is significant in guiding the pseudo dynamic test design of high-rise flexible structure and ensuring the rationality of test.

Nonlinear Model for Sub- and Superharmonic Motions of a MDOF Moored Structure, Part 1—System Identification

2005 ◽  
Vol 127 (4) ◽  
pp. 283-290 ◽  
Author(s):  
S. Raman ◽  
S. C. S. Yim ◽  
P. A. Palo
Keyword(s):  
System Identification ◽  
Nonlinear System Identification ◽  
Experimental System ◽  
Degree Of Freedom ◽  
System Model ◽  
Single Degree Of Freedom ◽  
Sdof System ◽  
Single Output ◽  
Motion Responses ◽  
Identification Technique

In this first part of a two-part study, the general nonlinear system identification methodology developed earlier by the authors for a single-degree-of-freedom (SDOF) system using the reverse-multi-input/single-output (R-MI/SO) technique is extended to a multi-degree-of-freedom (MDOF), sub-merged, moored structure with surge and heave motions. The physical nonlinear MDOF system model and the formulation of the R-MI/SO system-identification technique are presented. The corresponding numerical algorithm is then developed and applied to the experimental data of the MDOF system using only the subharmonic motion responses to identify the system parameters. The resulting model is then employed in Part 2 for a detailed analysis of both the sub and superharmonic dynamic behavior of the MDOF experimental system and a comparison of the MDOF response results and observations with those of the corresponding SDOF system examined earlier by the authors.

Evaluation of Seismic Damage of Multi-Storey RC Frames with Damage-Based Inelastic Spectra

2009 ◽  
Vol 12 (4) ◽  
pp. 529-546 ◽  
Author(s):  
Jianwu Wei ◽  
Yong Lu
Keyword(s):  
Structural Damage ◽  
Performance Indicator ◽  
Pushover Analysis ◽  
Seismic Damage ◽  
Alternative Methods ◽  
Response Analysis ◽  
Design Environment ◽  
Sdof System ◽  
Rc Frames ◽  
Equivalent Sdof System

In the context of performance-based design, structural damage as a comprehensive measure of the seismic demand against the available capacity may be used as an effective performance indicator. Accurate methods of damage estimation usually require sophisticated dynamic response analysis and yet they do not necessarily yield the best results due to the great uncertainties involved in the seismic input. A simple and rational method based on well-constructed response spectra could be more desirable, especially in a design environment. In this paper, a methodology is developed to estimate the seismic damage of multi-storey reinforced concrete (RC) frames in terms of both the overall (global) damage and the damage distribution. The multi-storey frame is first transformed into an equivalent SDOF system, so that the damage in the equivalent SDOF system can be found from the damage-based inelastic spectra for a specified seismic intensity. Numerical investigation on a series of generic frames under a selection of real ground motions indicates that the SDOF damage and the overall damage of the actual frame correlates in a consistent manner, thus the conversion from the established SDOF damage back to the overall frame damage is rather straightforward. Two alternative methods are proposed for the prediction of the distribution of damage along the frame height, one using the modal pushover analysis, and the other based on the structural characterization using a storey capacity factor.

Static Pushover Analysis Based on an Energy-Equivalent SDOF System

2011 ◽  
Vol 27 (1) ◽  
pp. 89-105 ◽  
Author(s):  
Grigorios Manoukas ◽  
Asimina Athanatopoulou ◽  
Ioannis Avramidis
Keyword(s):  
Pushover Analysis ◽  
Main Idea ◽  
Theoretical Background ◽  
Degree Of Freedom ◽  
Lateral Loads ◽  
External Work ◽  
Sdof System ◽  
New Energy ◽  
Equivalent Sdof System

In this paper, a new energy-based pushover procedure is presented in order to achieve an approximate estimation of structural performance under strong earthquakes. The steps of the proposed methodology are quite similar to those of the well-known displacement modification method. However, the determination of the characteristics of the equivalent single-degree-of-freedom (E-SDOF) system is based on a different rational concept. Its main idea is to determine the E-SDOF system by equating the external work of the lateral loads acting on the multi-degree-of-freedom (MDOF) system under consideration to the strain energy of the E-SDOF system. After a brief outline of the theoretical background, a representative numerical example is given. Finally, the accuracy of the proposed method is evaluated by an extensive parametric study which shows that, in general, it provides better results compared to those produced by other similar procedures.

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