scholarly journals EFFECT OF DAMPING RATIO ON THE ATTENUATION RELATIONSHIP OF RESPONSE SPECTRUM

2006 ◽  
Vol 62 (2) ◽  
pp. 384-392 ◽  
Author(s):  
Yoshihisa MARUYAMA ◽  
Fumio YAMAZAKI
Keyword(s):  
Response Spectrum ◽  
Damping Ratio ◽  
Attenuation Relationship ◽  
Relationship Of

A Study on Dynamic Properties of Cement-Stabilized Soils

2011 ◽  
Vol 243-249 ◽  
pp. 2050-2054 ◽  
Author(s):  
Pei Hsun Tsai ◽  
Sheng Huoo Ni
Keyword(s):  
Shear Modulus ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Test Results ◽  
Resonant Column Test ◽  
Stabilized Soil ◽  
Shearing Strain ◽  
Relationship Of ◽  
The Relationship

In this paper the dynamic property (shear modulus and damping ratio) of cement-stabilized soil is studied with using the resonant column test. The amount of cement admixed, the magnitude of confining pressure, and shearing strain amplitude are the parameters considered. Test results show that the maximum shear modulus of cement-stabilized soil increases with increasing confining pressure, the minimum damping ratio decreases with increasing confining pressure. The shear modulus of cement-stabilized soil decreases with increasing shearing strain while the damping ratio increases with increasing shearing strain. In the paper the relationship of shear modulus versus shearing strain is fitted into the Ramberg-Osgood equations using regression analysis.

Experimental Study on Seismic Responses of Piping Systems With Friction—Part 2: Simplified Analysis Method on the Effect of Friction

1995 ◽  
Vol 117 (3) ◽  
pp. 250-255
Author(s):  
H. Kobayashi ◽  
R. Yokoi ◽  
T. Chiba ◽  
K. Suzuki ◽  
N. Shimizu ◽  
...  
Keyword(s):  
Large Scale ◽  
Response Spectrum ◽  
Damping Ratio ◽  
Analysis Method ◽  
Equivalent Viscous Damping ◽  
Piping Systems ◽  
Simplified Analysis ◽  
Reduction Effect ◽  
Vibration Tests ◽  
Equivalent Viscous Damping Ratio

Friction between pipe and support structure is generally known to reduce seismic response of the piping systems. Vibration tests using large-scale piping model with friction support were carried out to evaluate the reduction effect. The piping response was mainly governed by the first modal deformation. The simplified analysis method based on linear response spectrum analysis was developed and confirmed to be applicable. In this method, the reduction effect by friction is treated as equivalent viscous damping ratio. This paper deals with the analysis method, and the comparison between the experimental results and analytical ones.

Convex Model for a New Lateral Load Pattern of Pushover Analysis

2011 ◽  
Vol 243-249 ◽  
pp. 4013-4016
Author(s):  
Li Zhe Jia ◽  
Zhong Dong Duan
Keyword(s):  
Response Spectrum ◽  
Pushover Analysis ◽  
Fundamental Equation ◽  
Lateral Load ◽  
Seismic Load ◽  
Influence Coefficient ◽  
Convex Model ◽  
Load Pattern ◽  
Relationship Of ◽  
Strong Ground

The uncertainties of earthquake currently were not considered with the various lateral load patterns of pushover. The convex set theory, which requires much less information, is employed to model the uncertainties of the seismic influence coefficient maximum and the characteristic period of response spectrum. Then the convex analysis method is integrated into the fundamental equation of pushover, and the analytic relationship of lateral seismic load and top displacement of buildings is derived. The results of numerical example shows that the new lateral load pattern of pushover proposed in this research may effective simulate the uncertainties of strong ground motion.

Response Spectrum Analysis Method of Footbridge Lateral Vibration under Man-Bridge Interaction

2013 ◽  
Vol 838-841 ◽  
pp. 1165-1169
Author(s):  
Yu Nan ◽  
Zhi Gang Song ◽  
Shi Jiao
Keyword(s):  
Design Method ◽  
Response Spectrum ◽  
Damping Ratio ◽  
Interaction Model ◽  
Dynamic Interaction ◽  
Stride Frequency ◽  
Social Force ◽  
Acceleration Response ◽  
Weighting Method ◽  
Acceleration Response Spectrum

Based on the uniform experimental design method and combining with the additional lateral pedestrian role derived from social force, this paper establishes human-bridge dynamic interaction model and calculates dynamic response of simply supported structures with different span, damping ratio, walking stride frequency and other parameters under the man-bridge dynamic interaction. The acceleration response spectrum is obtained by FFT transform of acceleration response. Then RMS-acceleration response spectrum is calculated in accordance with ISO overall frequency weighting method and the response spectrum envelope formula is fitted by parametric analysis.

A New Type of Hybrid-Passive-Damper

2010 ◽  
Vol 163-167 ◽  
pp. 4367-4372
Author(s):  
Ai Rong Liu ◽  
Qi Cai Yu ◽  
Yuan Yao ◽  
Yu Zhu Guo
Keyword(s):  
Energy Dissipation ◽  
Damping Ratio ◽  
Loading Frequency ◽  
Vibration Period ◽  
Equivalent Damping ◽  
Passive Damper ◽  
New Type ◽  
Energy Dissipation Capacity ◽  
Relationship Of ◽  
The Relationship

This paper investigated the superelasticity and hysteresis characteristics of TiNi shape memory alloy ( SMA ) wire at room temperature, then the mechanical parameters of which were obtained. Based on the TiNi SMA wire and a purchased viscous damper, a new type of hybrid-passive-damper was designed and developed. Experiments were performed in order to validate the relationship of loading frequency and characteristic parameters such as energy dissipation capacity, equivalent damping ratio and equivalent stiffness. Experimental results show that hybrid-passive-damper designed in this paper has excellent energy dissipation capacity and is suitable for the vibration control of structures with long vibration period.

A Blade Loss Response Spectrum for Flexible Rotor Systems

1985 ◽  
Vol 107 (1) ◽  
pp. 197-204 ◽  
Author(s):  
M. Alam ◽  
H. D. Nelson
Keyword(s):  
Response Spectrum ◽  
Damping Ratio ◽  
Response Spectra ◽  
Flexible Rotor ◽  
Peak Displacement ◽  
Rotor Systems ◽  
Displacement Response ◽  
Modal Damping Ratio ◽  
Whirl Speed ◽  
Blade Loss

A shock spectrum procedure is developed to estimate the peak displacement response of linear flexible rotor-bearing systems subjected to a step change in unbalance (i.e., a blade loss). A progressive and a retrograde response spectrum are established. These blade loss response spectra are expressed in a unique non-dimensional form and are functions of the modal damping ratio and the ratio of rotor spin speed to modal damped whirl speed. Modal decomposition using complex modes is utilized to make use of the unique feature of the spectra for the calculation of the peak blade loss displacement response of the rotor system. The procedure is applied to three example systems using several modal superposition strategies. The results of each are compared to true peak displacements obtained by a separate transient response program.

Response spectrum-based seismic response of bridge embankments

2020 ◽  
Vol 57 (11) ◽  
pp. 1639-1651
Author(s):  
Juan-Carlos Carvajal ◽  
William D. Liam Finn ◽  
Carlos Estuardo Ventura
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Seismic Response ◽  
Response Spectrum ◽  
Damping Ratio ◽  
Stress Profile ◽  
Cyclic Shear ◽  
Equivalent Linear ◽  
Design Response Spectrum ◽  
Peak Shear Stress

A single degree of freedom model is presented for calculating the free-field seismic response of bridge embankments due to horizontal ground shaking using equivalent linear analysis and a design response spectrum. The shear wave velocity profile, base flexibility, 2D shape, and damping ratio of the embankment are accounted for in the model. A step-by-step procedure is presented for calculating the effective cyclic shear strain of the embankment, equivalent homogeneous shear modulus and damping ratio, fundamental period of vibration, peak crest acceleration, peak shear stress profile, peak shear strain profile, equivalent linear shear modulus profile, and peak relative displacement profile. Model calibration and verification of the proposed procedure is carried out with linear, equivalent linear, and nonlinear finite element analysis for embankments with fundamental periods of vibration between 0.1 and 1.0 s. The proposed model is simple, rational, and suitable for practical implementation using spreadsheets for a preliminary design phase of bridge embankments.

scholarly journals A New Method to Calculate Additional Damping Ratio considering the Effect of Excitation Frequency

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Weizhi Xu ◽  
Dongsheng Du ◽  
Shuguang Wang ◽  
Weiwei Li
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Calculation Method ◽  
Response Spectrum ◽  
Damping Ratio ◽  
Excitation Frequency ◽  
Structural Dynamic ◽  
Important Indicator ◽  
Simplified Calculation ◽  
Simplified Calculation Method

The additional damping ratio (ADR) is an important indicator for evaluating the damping effect of structures with energy-dissipation devices. Most existing methods for determining the ADR require an analysis of the structural dynamic response and complex iterative calculations. An innovative simplified calculation method for determining the ADR of a structure supplemented by nonlinear viscous dampers is proposed. This method does not require the dynamic response of the structure to be calculated and only requires the structural characteristics, excitation frequency, and damper parameters. In this study, several typical calculation methods for the ADR were analysed. Then, a calculation formula for the ADR was derived with consideration of harmonic excitation under the condition where the excitation frequency is equal to the structural natural frequency, without calculation of the structural dynamic response or an iterative process. The effect of the excitation frequency on the calculated value of the ADR with different damping exponents was studied. Accordingly, the response spectrum average period (RSAP) was considered as the excitation period of ground motion to evaluate the excitation frequency, and a simplified calculation method for the ADR considering the effect of the excitation frequency characterised by the RSAP of the ground motion was established. Finally, the accuracy and effectiveness of the proposed method were verified by comparison with ADRs calculated using other methods.

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