Damping effect on seismic input energy and its verification by shake table tests

2021 ◽  
pp. 136943322110105
Author(s):  
Ahmet Gullu ◽  
Ercan Yuksel ◽  
Cem Yalcin ◽  
Oral Buyukozturk
Keyword(s):  
Damping Ratio ◽  
Shear Velocity ◽  
Energy Spectra ◽  
Input Energy ◽  
Shake Table Tests ◽  
Seismic Input ◽  
Damping Effect ◽  
Fundamental Frequencies ◽  
Modification Factor ◽  
Dominant Period

Seismic input energy per unit mass ( EI/m) imparted into a structure is a function of earthquake (duration, frequency content, amplitude etc.), soil (shear velocity, dominant period etc.) and the structural (vibrational periods etc.) characteristics. Generally, the damping properties of the structure is assumed negligible for seismic input energy. Most of the existing spectral equations derived for SDOF systems generally use a constant damping ratio of 5%. In this study, the damping effect on EI/m is investigated experimentally and numerically on SDOF systems with distinct damping ratios. Experimental investigation and numerical computations proved that seismic input energy is very sensitive to variation of damping within the vicinity of fundamental frequencies. Specifically, up to 50% increment was observed in the plateau region of the input energy spectrum, where maximum EI/m values occur, by variation of damping from 2% to 10%. Hence, a novel damping modification factor ( DMF), which could be utilized for existing energy spectra, is proposed in this paper. Validation studies of the proposed DMF are achieved through the various energy spectra found in the literature.

A Study on Elastic Input Energy Spectra Based on the Compound Intensity Indicator

2012 ◽  
Vol 446-449 ◽  
pp. 140-145
Author(s):  
Li He ◽  
Xian Guo Ye
Keyword(s):  
Ground Motion ◽  
Damping Ratio ◽  
Energy Spectra ◽  
Site Classification ◽  
Input Energy ◽  
Damage Potential ◽  
Normalization Methods ◽  
Seismic Records ◽  
Energy Based Design

Determination of a SDOFS elastic input energy is the primary problem to solve for energy-based design approach. The effect of ground motion and damping ratio were analyzed on the input energy spectra. is selected as the compound ground motion intensity indicator to represent the damage potential of strong ground motion. Through inputting of 188 seismic records according to the site classification of Chinese seismic code, three-segment elastic energy spectra are proposed based on normalization methods. The calculation formula of the peak and the value of long-period section of the input energy spectra are presented for four categories of site conditions by statistical analysis. Moreover, calculation procedure of the total energy input is given in the paper.

The Influence of Support Hardware and Piping System Seismic Response on Snubber Support Damping

1997 ◽  
Vol 119 (4) ◽  
pp. 451-456 ◽  
Author(s):  
C. Lay ◽  
O. A. Abu-Yasein ◽  
M. A. Pickett ◽  
J. Madia ◽  
S. K. Sinha
Keyword(s):  
Seismic Response ◽  
Fundamental Frequency ◽  
Damping Ratio ◽  
Damping Coefficient ◽  
Piping System ◽  
Nodal Displacement ◽  
Damping Coefficients ◽  
Fundamental Frequencies ◽  
Piping Systems

The damping coefficients and ratios of piping system snubber supports were found to vary logarithmically with pipe support nodal displacement. For piping systems with fundamental frequencies in the range of 0.6 to 6.6 Hz, the support damping ratio for snubber supports was found to increase with increasing fundamental frequency. For 3-kip snubbers, damping coefficient and damping ratio decreased logarithmically with nodal displacement, indicating that the 3-kip snubbers studied behaved essentially as coulomb dampers; while for the 10-kip snubbers studied, damping coefficient and damping ratio increased logarithmically with nodal displacement.

Response of Liquid in Cylindrical Tank with Rigid Annual Baffle Considering Damping Effect

2011 ◽  
Vol 255-260 ◽  
pp. 3687-3691 ◽  
Author(s):  
Jia Dong Wang ◽  
Ding Zhou ◽  
Wei Qing Liu
Keyword(s):  
Free Surface ◽  
Dynamic Response ◽  
Potential Function ◽  
Natural Frequencies ◽  
Damping Ratio ◽  
Cylindrical Tank ◽  
Generalized Coordinates ◽  
Damping Effect ◽  
Total Potential ◽  
Free Surface Wave

Sloshing response of liquid in a rigid cylindrical tank with a rigid annual baffle under horizontal sinusoidal loads was studied. The effect of the damping was considered in the analysis. Natural frequencies and modes of the system have been calculated by using the Sub-domain method. The total potential function under horizontal loads is assumed to be the sum of the tank potential function and the liquid perturbed function. The expression of the liquid perturbed function is obtained by introducing the generalized coordinates. Substituting potential functions into the free surface wave conditions, the dynamic response equations including the damping effect are established. The damping ratio is calculated by Maleki method. The liquid potential are obtained by solving the dynamic response equations of the system.

scholarly journals Response Site Analyses of 3D Homogeneous Soil Models

2018 ◽  
Vol 2 (5) ◽  
pp. 238 ◽  
Author(s):  
Davide Forcellini ◽  
Marco Tanganelli ◽  
Stefania Viti
Keyword(s):  
Soil Type ◽  
Soil Depth ◽  
Site Response ◽  
Soil Layer ◽  
Shear Velocity ◽  
Seismic Intensity ◽  
Eurocode 8 ◽  
Seismic Input ◽  
Homogeneous Soil ◽  
Response Site

The seismic excitation at the surface can be determined through Site Response Analyses (SRA) as to account for the specific soil properties of the site. However, the obtained results are largely affected by the model choice and setting, and by the depth of the considered soil layer. This paper proposes a refined 3D analytical approach, by the application of OPENSEES platform. A preliminary analysis has been performed to check the model adequacy as regards the mesh geometry and the boundary conditions. After the model setting, a SRA has been performed on various soil profiles, differing for the shear velocity and representing the different soil classes as proposed by the Eurocode 8 (EC8). Three levels of seismic hazard have been considered. The seismic input at the bedrock has been represented consequently, through as much ensembles of seven ground motions each, spectrum-compatible to the elastic spectra provided by EC8 for the soil-type A (bedrock). Special attention has been paid to the role of the considered soil depth on the evaluation of the surface seismic input. Different values of depth have been considered for each soil type and seismic intensity, in order to check its effect on the obtained results.

Dynamic Vibration Absorber for a Ropeway Carrier

1997 ◽  
Author(s):  
Hiroshi Matsuhisa ◽  
Osamu Nishihara
Keyword(s):  
Natural Frequency ◽  
Damping Ratio ◽  
Vibration Absorber ◽  
Moving Mass ◽  
Dynamic Vibration Absorber ◽  
Damping Effect ◽  
The World ◽  
Dynamic Absorber ◽  
First Time ◽  
Suspended Bridge

Abstract Ropeways such as gondola lifts have attracted increasing interest as a means of transportation in cities. However, swing of ropeway carriers is easily caused by wind, and usually a ropeway cannot operate if the wind velocity exceeds about 15m/s. The study of how to reduce the wind-induced swing of ropeway carriers has attracted many researchers. It had been said that it was impossible to reduce the vibration of pendulum type structures such as ropeway carriers by a dynamic absorber. But in 1993, Matsuhisa showed that the swing of carrier can be reduced by a dynamic absorber if it is located far above or below from the center of oscillation. Based on this finding, a dynamic absorber composed of a moving mass on an arc-shaped track was designed for practical use, and it was installed in chairlift-type carriers and gondola type carriers in snow skiing sites in Japan in 1995 for the first time in the world. It has been shown that a dynamic absorber with the weight of one tenth of the carrier can reduce the swing to half. The liquid dynamic absorber was also investigated. It has the same damping effect as the conventional solid absorber. It is easy to adjust the natural frequency and the damping ratio, and the structure is simple. Therefore, it will be applied for not only ropeway carriers but also ships and rope suspended bridge and others.

Input energy spectra for self-centering SDOF systems

2019 ◽  
Vol 121 ◽  
pp. 293-305 ◽  
Author(s):  
Ying Zhou ◽  
Ge Song ◽  
Shimin Huang ◽  
Hao Wu
Keyword(s):  
Energy Spectra ◽  
Input Energy

Simulating Maximum and Residual Displacements of RC Structures: II. Sensitivity

2011 ◽  
Vol 27 (4) ◽  
pp. 1203-1218 ◽  
Author(s):  
Ufuk Yazgan ◽  
Alessandro Dazio
Keyword(s):  
Damping Ratio ◽  
Time Integration ◽  
Integration Step ◽  
Discretization Scheme ◽  
Hysteretic Model ◽  
Step Size ◽  
Shake Table Tests ◽  
Rc Structures ◽  
Residual Displacements ◽  
Response History Analysis

The simulated response of a structure subjected to seismic excitation is sensitive to the idealizations made to model its response. This paper examines critical idealizations and assumptions that have a strong influence on the accuracy of the maximum and residual displacements predicted by response-history analysis. A set of shake table tests are numerically reproduced for this purpose. The investigated idealizations include the discretization scheme, the axial load, the steel hysteretic model, the viscous damping ratio, and the time-integration step size. The results indicate that the simulated residual displacements are significantly more sensitive to the model idealizations than the maximum displacements. It is found that the adopted discretization scheme and the utilized steel hysteresis model have very large influences on simulated residual displacements.

Sign in / Sign up

Export Citation Format

Share Document