The shape of the seismic response interaction diagram: The effect of combination rules in response spectrum analysis

2020 ◽  
Vol 49 (14) ◽  
pp. 1428-1451
Author(s):  
Manuel Ritto‐Corrêa ◽  
Ana Rita Tomaz ◽  
Luís Guerreiro
Keyword(s):  
Seismic Response ◽  
Spectrum Analysis ◽  
Response Spectrum ◽  
Response Spectrum Analysis ◽  
Combination Rules ◽  
Interaction Diagram

scholarly journals A Literature Review on Seismic Response of Floating Column Building

2021 ◽  
Vol 9 (12) ◽  
pp. 68-72
Author(s):  
Deepak Jain
Keyword(s):  
Literature Review ◽  
Seismic Response ◽  
Spectrum Analysis ◽  
Response Spectrum ◽  
Seismic Loads ◽  
Seismic Zone ◽  
Response Spectrum Analysis ◽  
Promising Solution ◽  
Story Building ◽  
Shape And Size

Abstract: Floating column building is a new fascination for engineers. As floating column buildings provides more space and good aesthetics to the building. But have high structural challenges, when a floating column is provided in a multi-story building in a high seismic zone. This paper reviews several studies conducted on the floating column building and its behavior under seismic loads. This paper studies that floating column building are vulnerable to the high seismic zones. The risk of damage also depends on the shape and size of the buildings.The ductile detailing of the joints is the promising solution for immediate failure of such buildings. Keywords: Floating Column, Response spectrum analysis. Vulnerable, damage, multi-story

The Application of Harmonic Finite Elements in the Seismic Response Spectrum Analysis of a Skirt Supported Vessel

2010 ◽  
Author(s):  
Bikramjit Singh Antaal ◽  
Yogeshwar Hari ◽  
Dennis K. Williams
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Seismic Response ◽  
Spectrum Analysis ◽  
Degrees Of Freedom ◽  
Response Spectrum ◽  
Response Spectrum Analysis ◽  
Element Analysis ◽  
Structure Interaction ◽  
Input Response

This paper describes the finite element considerations employed in a seismic response spectrum analysis of a skirt supported, liquid containing pressure vessel. Like many axisymmetric cylindrical vessels, the gross seismic response to an input response spectrum can be categorized by a simplified lump mass model that includes both the mass of the vessel proper in combination with the associated mass of multiple fluid levels. This simplified response may be utilized to determine the initial sizing of the supporting configuration, such as a skirt, but lacks the ability to properly address the fluid-structure interaction that creates sloshing loads on the vessel walls. The most obvious method to address the fluid-structure interaction when considering the finite element method is to build a three-dimensional model of the vessel proper, including, but not limited to the shell courses, the top and bottom heads (for a vertical vessel), and the support skirt. The inclusion of the fluid effects may now be incorporated with a “contained fluid” finite element, however, for vessels of any significant volume, the number of finite elements can easily exceed 100,000 and the number of degrees of freedom can sore from as few as 300,000 to as many as 500,000 or more. While these types of finite element analysis problems can be solved with today’s computer hardware and software, it is not desirable in any analysis to have that volume of information that has to be reviewed and approved in a highly regulated nuclear QA environment (if at all possible). With these items in mind, the methodology described in this paper seeks to minimize the number of degrees of freedom associated with a response spectrum analysis of a liquid filled, skirt supported vertical pressure vessel. The input response spectra are almost always provided in Cartesian coordinates, while many, if not most liquid containing pressure vessels are almost always axisymmetric in geometry without having benefit of being subjected to an axisymmetric load (acceleration in this case) due to the specified seismic event. The use of harmonic finite elements for both the vessel structure and the contained fluid medium permit the efficiencies associated with an axisymmetric geometry to be leveraged when the seismic response spectrum is formulated in terms of a Fourier series and combined to regain the effects of the two orthogonal, horizontally applied accelerations as a function of frequency. The end result as discussed and shown in this paper is a finite element model that permits a dense mesh of both the fluid and the structure, while economizing on the number of simultaneous equations required to be solved by the chosen finite element analysis.

Torsional Displacements in Base-Isolated Buildings

2000 ◽  
Vol 16 (2) ◽  
pp. 443-454 ◽  
Author(s):  
R. S. Jangid ◽  
J. M. Kelly
Keyword(s):  
Spectrum Analysis ◽  
Analytical Study ◽  
Response Spectrum ◽  
Equations Of Motion ◽  
Governing Equations ◽  
Response Spectrum Analysis ◽  
Combination Rules ◽  
Torsional Response ◽  
Torsional Coupling ◽  
Torsional Frequency

An analytical study of the effects of torsional coupling on the seismic response of a base-isolated building is presented. The isolated structure is modeled as a rigid deck supported on axially inextensible bearings. The governing equations of motion for the coupled lateral-torsional response of the system are derived. The eccentricity in the system is that specified by the Uniform Building Code (UBC). The displacement response of the isolated system with different combinations of building configuration, isolation damping, and the ratio of uncoupled torsional to lateral frequency of the system is investigated. The response of the isolated structure under a variety of near-fault and other earthquake ground motions is compared to that obtained by use of response spectrum analysis. In the response spectrum analysis the accuracy of several modal combination rules is evaluated. It is shown that torsional coupling can influence the response of the isolated structure, but if the layout of the isolation bearings is such that the torsional frequency is larger than the lateral frequency, the effect is reduced and the usual modal combination rules work well. It is also shown that in this case, the UBC static formula for the additional isolator displacements due to torsion is conservative.

A fuzzy random approach of stochastic seismic response spectrum analysis

2010 ◽  
Vol 32 (12) ◽  
pp. 3879-3887 ◽  
Author(s):  
Giuseppe Carlo Marano ◽  
Emiliano Morrone ◽  
Sara Sgobba ◽  
Subrata Chakraborty
Keyword(s):  
Seismic Response ◽  
Spectrum Analysis ◽  
Response Spectrum ◽  
Response Spectrum Analysis ◽  
Stochastic Seismic Response ◽  
Random Approach ◽  
Fuzzy Random

scholarly journals Study on Performance of Floating Column with Different Configurations

2021 ◽  
pp. 749-759
Author(s):  
Gokul Kishore K S ◽  
Manju R
Keyword(s):  
Seismic Response ◽  
Spectrum Analysis ◽  
Response Spectrum ◽  
Structural Response ◽  
Lateral Stability ◽  
Load Path ◽  
Response Spectrum Analysis ◽  
Ground Floor ◽  
Earthquake Loads

Floating column is a type of columns which distributes the load to beams rather than foundation. This is common in multi storey buildings which are anticipated to accommodate parking at ground floor or open halls at higher floors. These columns have discontinuities in the load path when a column coming from top of the building is discontinued at a lower level, usually at the ground storey. The structure with floating column should be designed for earthquake loads so these buildings will be in seismic prone areas. In this study, the effect of various lateral stability techniques to the building with floating columns on various structural response quantities of the building using response spectrum analysis is studied. The main objective here is to study the seismic response of building with floating columns with various lateral stability techniques and to find out the most appropriate configuration for providing floating columns. Various parameters such as story displacement, storey drift, story shear, story stiffness of a building is studied with respect to different configurations of floating columns.

Modal Combination in Response Spectrum Analysis of Piping Systems

1986 ◽  
Vol 108 (1) ◽  
pp. 73-77 ◽  
Author(s):  
A. K. Gupta ◽  
J.-W. Jaw
Keyword(s):  
Spectrum Analysis ◽  
Response Spectrum ◽  
Direct Integration ◽  
Response Spectrum Analysis ◽  
Combination Rules ◽  
Combination Methods ◽  
Modal Response ◽  
Piping Systems ◽  
Higher Modes Effect ◽  
Integration Analysis

Modal combination methods in the response spectrum analysis of piping systems have been investiaged. Two particular effects are identified, viz, (i) the residual rigid response, also known as the higher modes effect (HME); (ii) the correlation between the modal response and the rigid response. Gupta’s method accounts for both these effects. It is shown that Gupta’s method gives results which are much closer to the direct integration analysis results than are the results obtained from any other modal combination rules which ignore either one or both of the foregoing effects.

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