Introduction the most direct description of an earthquake motion in time domain is provided by accelerograms that are recorded by instruments called strong motion accelerographs. A comparative analysis on absolute and srss methods of. Response spectra are curves plotted between maximum response of sdof system subjected to specified earthquake ground motion and its time period or. Comparative study of equivalent static analysis and response. Since the exact time history of the load is not known, it is difficult to perform a timedependent analysis.
Response spectrum analysis is a method to estimate the structural response to short, nondeterministic, transient dynamic events. Examples of such events are earthquakes and shocks. Analysis of building with response spectrum method seismic analysis of highrise building having following data is analyzed for different models of lateral load resisting systems. Dynamic analysis using response spectrum seismic loading before the existence of inexpensive personal computers, the response spectrum method was the standard approach for linear seismic analysis 15. Modal analysis is performed to identify the modes, and the response in that mode can be picked from the response spectrum. Response spectrum analysis of structures subjected to seismic actions chapter pdf available january 20 with 4,654 reads how we measure reads. Thereby, a fuzzy version of the classical stochastic response spectrum evaluation of linear systems is obtained. What matters is how the buildings respond to earthquakes. A comparison is done between the static and dynamic analysis, the results such as bending moment, nodal displacements, mode shapes are observed, compared. Response spectrum method of analysis mechanical engineering. Singlepoint response spectrum a single response spectrum excites all specified points in the model. Caepipe will apply these loads to compute the response of the piping system by performing a response spectrum analysis along with other load cases defined in the piping system. Instructional material complementing fema 451, design examples seismic load analysis 9 17 1a, 1b stiffness soft story irregularity vertical structural irregularities irregularity 1a exists if stiffness of any story is less than 70% of the stiffness of the story above or less than 80% of the average stiffness of the three stories above.
A fuzzy random approach of stochastic seismic response. Aug 31, 2018 response spectrum analysis in etabs 2016 duration. Response spectra can also be used in assessing the response of linear systems with multiple modes of oscillation multidegree of freedom systems, although they are only accurate for low levels of damping. Timehistory method the sdof response spectrum method can be used as long the structure or equipment can be modeled by a single degree of freedom system consisting of a spring, mass and damping. Introduction analysis and design of buildings for static forces is a routine affair these days because of the availability of affordable computers and specialized programs which can be. Using the acceleration response spectrum, an equivalent static load is derived which will provide the same maximum response as that obtained in each. Harmonic analysis and cepstral analysis advanced parametric sinusoidal modeling is offered with your choice of frequency estimation methods. View response spectrum analysis research papers on academia. Response spectrum analysis massachusetts institute of. Response spectrum analysis and nonlinear properties.
Spectrum obtained by dividing the acceleration spectrum by the acceleration of gravity. Construction of design response spectrum the chilean way. Response spectrum analysis can be used to estimate the peak response displacement, stress, etc. Comparative study these earthquake methods are carried out and presented and explained here. Should i specify response spectrum in all directions in the. Before addressing the details of the shock response spectrum, a few definitions and examples may be helpful. In this case ddam for abaqus calculates the peak response due to each individual spectrum in the combination and writes the extreme peak response over all of the spectra to the ddam response output database. A thesis presented to the university of waterloo in fulfilment of the. Earthquake engineering, reliability analysis, earthquake engineering, fragility curves, shear wall system, flat slab structures. Lets assume the excitation angle 0 and building principle direction is u1 so i will apply response spectrum function per ibc 2006 in u1 direction by a scale factor.
Pdf in the framework of seismic design of structures, response spectrum analysis rsa is the most commonly used approach in practice. Response spectrum analysis the seismic loads are taken into account according to the response spectrum analysis method. Seismic analysis modal spectral analysis it defines the seismic behavior of the structure as the superposition of n. Shock response spectrum srs use the shock response spectrum srs to estimate the damage potential of mechanical impulses or stationary random vibrations. Response spectrum analysis in etabs software issues. The consistency of fuzzy stochastic response spectrum obtained by the proposed approach is studied with respect to available nonprobabilistic formulations reported in the literature.
Response spectrum analysis of structures subjected to spatially. Seismic analyzed coefficient method analysis is done using manual calculation and response spectrum method analysis is done using staadprov8i. Shock response spectrum analysis is the maximum response of a series of single degree of freedom systems having the same damping to a given transient signal. The method is based on the assumption that the input excitation is a wideband. Spectral analysis of signalspetre stoica and randolph moses p.
Seismic analysis of multistoried rc building presented by rahul leslie. Note that milstd1540c and milstd810e require this format for certain shock environments. Cascaded analysis of secondary systems using response spectrum method. The material properties such as grade of concrete, yield strength of steel, modulus of elasticity and. Johnson department of earth and environmental science, new mexico tech 1. Earthquake analysis and design of simple structures and. Staad utilizes the following procedure to generate the lateral seismic loads. This method requires a previously calculated number of undamped free vibration frequencies and the corresponding mode shapes. The first data reported from an earthquake record is generally the peak ground acceleration pga which expresses the tip of the maximum spike of the acceleration ground motion figure 1. Pdf response spectrum analysis of structures subjected to. Assistant vice president of production and manufacturing. Response spectrum analysis research papers academia.
Responsespectrum analysis technical knowledge base. Include response spectrum analysis load case through layout window load cases. Comparative study of static and dynamic seismic analysis of a. Dynamic design analysis method ddam response spectrum. The accelerograph records three orthogonal components of ground acceleration. Consider the following periodic triangle wave signal, having period t0 4ms, shown here graphically. This paper presents the effect of response spectrum analysis and construction sequence analysis on the setback steel structure. February 12, 2016 response is what an object, living or nonliving, gives to a certain situation. A response spectrum method for stationary random vibration analysis of linear structures is developed. Responsespectrum analysis rsa is a lineardynamic statistical analysis method which measures the contribution from each natural mode of vibration to indicate the likely maximum seismic response of an essentially elastic structure. Save the model and perform the analysis through layout window file analyze. The response spectrum method rsm was introduced in 1932 in the doctoral dissertation of maurice.
The sdof response spectrum method usually gives less conservative results than simplified procedures, yet easy to. The result is obtained and studied and compared to derive conclusion. Using response spectrum method with the help of analysis and design tool staad pro v8i, to evaluate analysis parameters such as nodal displacement, shear forces in column, compressive and tensile. Pdf response spectrum analysis of frame structures. Structural dynamic it is the response analysis for structure. Obtaining joint accelerations for response spectrum analysis of multidof structure. Keywords dynamic analysis, response spectrum method, absolute method, srss method, joint displacement, story drift, staad pro analysis, staad generic method. Then open the response spectrum and insert rs displacment. In the blog post about response spectrum analysis i, i tried to describe response of the system, but one comment on the post rightly pointed out as the concept of spectrum was not described clearly, so in this post we will be talking about the concept spectrum and how it is generated, what it signifies and how is it helpful for engineers to understand the dynamic forces acting on the building. The following illustrations show examples of transient shock. Tutorial for response spectrum analysis using caepipe. Response spectrum method of analysis seismic analysis of. Responsespectrum analysis etabs computers and structures. Comparative study of equivalent static analysis and.
However, as response spectra and dynamic analysis are being included within the newer building codes and as performancebased design pbd techniques are. The naval shock design spectrum including the spectrum dip phenomenon. A response spectrum is a plot of the peak or steadystate response displacement, velocity or acceleration of a series of oscillators of varying natural frequency, that are forced into motion by the same base vibration or shock. Nuclear power plant buildings and components, for seismic loading airborne electronic equipment for shock loading commercial buildings in earthquake zones types of response spectrum analysis. Response spectrum analysis rsa is a lineardynamic statistical analysis method which measures the contribution from each natural mode of vibration to indicate the likely maximum seismic response of an essentially elastic structure.
Response spectrum analysis midas civil dynamic analysis step 1. Comparison of some code provisions prescribed by different earthquake codes. The natural frequencies obtained during a response spectrum analysis do not match the calculate rayleigh frequency when specifying damping, the displacements and forces remain same why are beam graphs not displayed for response spectrum load cases in staad. Response spectrum method of analysis with simplified.
Response spectra as a useful design and analysis tool for. As a result, when modal response spectrum analysis is used, a threedimensional model is required for all structures, including those with diaphragms that can be designated as flexible. Aug 30, 20 response spectrum analysis in staad explanation video methodology. How a shock response spectrum can be used in the analysis of linear multidof degree of freedom systems. To compare equivalent static analysis and response spectrum analysis method on flat slab for above parameters.
Sep 10, 20 the response spectrum method of analysis is developed using the following steps. Approximate modal response spectrum method of analysis. The response spectrum method of analysis is developed using the following steps. Comparative study of static and dynamic seismic analysis. The design lateral shear force at each floor in each mode is computed by staad in accordance with the is. Dynamic analysis of multistory building using response. Mar 25, 2010 cascaded analysis of secondary systems using response spectrum method. The material properties such as grade of concrete, yield. The shock response spectrum is a useful tool for estimating the damage potential of a shock pulse, as well as for test level specification. Response spectrum method of analysis free download as powerpoint presentation. When defining response spectrum load case in etabs, we have three directions.
The resulting plot can then be used to pick off the response of any linear system, given its natural frequency of oscillation. Response spectrum is an important tool in the seismic analysis and design of structures. It can be passive response or active response but it doesnt matter. The method is only approximate, but it is often a useful, inexpensive method for preliminary design studies. A response spectrum that is a combination of any previously created spectra can also be created. The purpose of this report is to explain the shock response spectrum and to give a. Seismic design of buildings worked examples worked examples presented at the workshop ec 8. In the framework of seismic design of structures, response spectrum analysis rsa is. Seismic analysis of highrise building by response spectrum. Response spectrum method, time history method,earthquake, dynamicanalysis. Response spectrum analysis rsa is currently the most popular. Should i specify response spectrum in all directions in. Then add a response spectrum from fra modal solution.
This dynamic analysis is analyzing a code or structure of a program while running the program. Pdf response spectrum analysis of structures subjected. I do not think it would be reasonable to consider pdelta analysis with response spectrum load cases the basic reason behind this is that the results of response spectrum would loose signs as soon as the modal combination is done using methods. Introduction the basis of engineering seismology is the need to quantify how a given structure will respond to complex ground motions. A modified response spectrum model is developed for. Response spectrum analysis of building is carried out using advanced version of software staadprov8i whereas seismic coefficient analysis is done using hand calculation from codal formula. Responsespectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration, velocity, or displacement as a function of. Response spectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration. Earthquake analysis with sap2000 response spectrum analysis response spectrum analysis is performed to verify that the column design is adequate. Pdf study on the effect of response spectrum analysis and. In this study, the proposed building is eleven storey setback steel structure.
Theory of response spectrum analysis earth and environmental. A research for high strength and better performance characterstics of floor and roof systems are designed to carry gravity loads and transfer these loads to supporting beams, columns or walls. Response spectrum analysis in staad explanation video methodology. Responsespectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration, velocity, or displacement as a function of structural. Selection of case study building, its response spectrum analysis and design of the full structure is presented here. The structures response is determined by its mass and stiffness distributions. I do not think it would be reasonable to consider pdelta analysis with response spectrum load cases the basic reason behind this is that the results of response spectrum would loose signs as soon as the modal combination is done using methods like srss, cqc etc. Divide only t 1 response by r other modes respond elastically. It requires to define a design response spectrum,in general, a spectrum of pseudo. Response spectra for seismic analysis and design core. Each lognormal bivariate joint probability density function jpdf is. My question is why we dont apply u2 and u3 in the same load case. Response spectrum functions load response spectrum analysis response spectrum analysis functions design spectrum in the database of midas civil can be used normalized acceleration.
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