Equivalent lateral force for an earthquake is defined as a set of lateral force which will produce the same peak response as that obtained by dynamic analysis of structures. Seismic analysis single point response spectrum analysis of vertical frame structure, part2 duration. The building under consideration is modeled with the help of sap200015 software. Response spectrum analysis is widely used for the design and assessment of structures that are subject to earthquakes or shock events. A response spectrum analysis calculates the maximum response of a structure to transient loads such as displacement,velocity or acceleration, that are forced into vibration by a base vibration or shock. What is the difference between equivalent static analysis and. Earthquake engineering, reliability analysis, earthquake engineering, fragility curves, shear wall system, flat slab structures. The motivation for moving linear response history lrh analysis from chapter 16 to chapter.
Response spectrum analysis in sap2000 dear all in continuation to the above listed thread. The same model was used for elf, modal response spectrum and modal. A replacement for the srss method in seismic analysis, e. Comparison of some code provisions prescribed by different earthquake codes.
The accelerograph records three orthogonal components of ground acceleration. From a simple small 2d static frame analysis to a large complex 3d nonlinear dynamic analysis, sap2000 is the answer to all structural analysis and design needs. Johnson department of earth and environmental science, new mexico tech 1. Response spectrum analysis in sap2000 civil engineering. Responsespectrum analysis generates the likely maximum response that a structure may experience in either direction. 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. Response spectrum analysis in sap2000 computers and. Responsespectrum analysis 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. Finite element approach is used to analyze the dam and a concretegravity dam model is prepared in staadpro to perform the time history analysis and response spectrum analysis and comparison is done between both these methods. For each damping value the magnitude of the response spectrum must be given over the entire range of frequencies needed, in ascending value of frequency. We are committed to delivering uninterrupted software services worldwide during the covid19 crisis. Comparative study of static and dynamic seismic analysis of a.
A three dimensional modeling and analysis of the structure are carried out with the help of sap 2000 software. The analysis of structure by using equivalent static method, time history method and response spectrum method has been surveyed. Mar 11, 2014 seismic analysis is a subset of structural analysis and is the calculation of the response of a building or nonbuilding structure to earthquakes. Created by faisal habib, last modified by ondrej on may 09, 20. Lateral loads are far too high for mounting structure to survive. The analysis of the structure for accidental torsion was performed using sap2000. Base response spectrum 2005 nbcc v f a,vs am vi ew r dr o 1995 nbcc v vsifw ru j revised for uhs j mdof overturning forces f t same as 1995 f t higher force in top story mdof distribution of forces m v calibrated to dyn.
Study of base shear and storey drift by dynamic analysis. The acceleration response spectra is represented as piecewise linear segments, whose endpoints are defined by a time, acceleration coordinate. Response spectrum method of analysis free download as powerpoint presentation. Sap2000 features sap2000 is available in three different levels. Response spectrum analysis of asymmetrical building ijssbt. This is similar to the pure eventtoevent method available for nonlinear directintegration time history analysis, and is in addition to the iterative eventtoevent stepping strategy already available for nonlinear static load cases. The response is calculated for each direction separately. Structural analysis using sap2000 civil engineering.
Responsespectrum analysis faq technical knowledge base. February 12, 2016 response is what an object, living or nonliving, gives to a certain situation. View source view scaffolding xml export to pdf export to word. Let us say for an example, you take a pendulum and you pull it to a. Pdf response spectrum analysis of frame structures. In dynamic analysis, it is useful to display base shear and base overturning moment for comparison with results from equivalent static analysis. Cascaded analysis of secondary systems using response spectrum method. Responsespectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration, velocity, or displacement as a. Sap2000 water tank manuals pdf carry out static analysis of underground water tank with the following details.
Response spectrum method of analysis mechanical engineering. For dynamic response spectrum analysis, define theresponse spectrum function and then response spectrum case using the procedure similar to that for static case. Nonlinear static analysis is an improvement over linear static or dynamic analysis in the sense that it allows inelastic. During the course of the project, several insights relating to potential improvements in the methodology for seismic analysis were identified and documented. Theoretical basis for response spectrum calculations in spectral analysis understand that the method of determining response spectrum sasat for a given diagram of accelerations ft, where t refers to period, sa refers to acceleration spectrum, t refers to time, while ft is a given time analysis function. Responsespectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration, velocity, or displacement as a function of structural. Sap2000 and etab analysis respectively as shown in fig 7. Approximate modal response spectrum method of analysis. Response spectrum analysis and equivalent static analysis. Moreover, some commercial computer programs with modal response spectrum analysis capability may not perform such an analysis in accordance with the relevant requirements of eurocode 8.
Response spectrum output problem in sap2000 computers. Response spectrum output problem in sap2000 computers and. Response spectrum analysis in etabs software issues. Earthquake analysis with sap2000 response spectrum analysis response spectrum analysis is performed to verify that the column design is adequate. In addition to specifying the modal damping ratio and function damping ratio, is it required to define m. Modal response spectrum analysis earthquake resistance. Response spectrum method of analysis seismic analysis of. 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. Selection of case study building, its response spectrum analysis and design of the full structure is presented here. The deflected shape for a linearadd load combination which contains a response spectrum load case will display either the minimum or maximum displacements, depending on which has the greater absolute value. We are committed to delivering uninterrupted software services worldwide during the. This type of analysis is useful in the case of dynamic loading like earthquakes. Equivalent static method of analysis and response spectrum analysis method are used for the analysis of both composite and r.
Why does responsespectrum analysis generate identical deflected. 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. Response spectrum analysis is performed to verify that the column design is adequate. The storey displacements and displacement of center of mass results have been obtained by using both static and dynamic analysis. I am encountering another problem while performing response spectrum in sap2000 i am analysing a mat foundation in sap df is a load case with dead load and sy is for response spectrum in orthogonal y direction. Pdf in the framework of seismic design of structures, response spectrum analysis rsa is the most commonly used approach in practice. Seismic analysis of highrise building by response spectrum. So i will apply response spectrum function per ibc 2006 in u1 direction by a scale factor.
Linear dynamic analysis response spectrum method is the linear dynamic analysis. Response spectrum analysis shock and seismic in femap. Jun 23, 2012 so i will apply response spectrum function per ibc 2006 in u1 direction by a scale factor. Figure 3 shows the lower half of the earthquake acceleration response spectrum that we will use for the analysis. Highlights from chapter 12 of asce 716 provisions for linear. This document constitutes the teaching course material structural analysis with sap2000 program that has been taught since march 2010 date of 1st edition in the ets of civil engineering, channels and ports of the university of granada through the general foundation university of granadaenterprise. My question is why we dont apply u2 and u3 in the same load case. Aug 30, 2016 for the love of physics walter lewin may 16, 2011 duration. Etabs 2015 tutorial 5 response spectrum analysis using is. The spectrum can be used in the subsequent response spectrum analysis, or it can be written to a file for future use. Response spectrum analysis generates the likely maximum response that a structure may experience in either direction. Response spectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration, velocity, or displacement as a function of structural period for a given time history and level of damping. Responsespectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration, velocity, or displacement as a function of. However, none of the above literature explains appropriate software method for seismic analysis.
Mar 21, 2015 modal and response spectrum is 18932002 analysis 0f r. Response spectrum analysis with eigen or ritz vectors a, p, b pdelta analysis a, p, b. The effective damping of the isolated modes of response is limited to 30 percent of critical. Responsespectrum analysis technical knowledge base. Introduction one of the emerging fields in seismic design of structures is the performance based design. Comparative study of static and dynamic seismic analysis. Response spectrum analysis of a simple planar frame. It is observed from the comparative study that the base shear using is code is higher in all the three buildings.
Rcc buildings, equivalent static analysis, response spectrum analysis, displacement. Dynamic analysis of multistory building using response. Calculation of centre of mass hinge centre of masses are applied based on the femaat grid x, y. Can sap2000 develop response spectra for a given location within the structure. Sap2000 seismic analysis civil engineering community. The response spectrum method of analysis is developed using the following steps. Introduction the basis of engineering seismology is the need to quantify how a given structure will respond to. Nov 08, 2017 response spectrum analysis of a simple planar frame. The objective of the this study is to carry out static and dynamic analysis i.
Shock response spectrum analysis results result is a single output set containing the combined responses of the spectrum analysis. Response spectrum analysis of structures subjected to seismic actions chapter pdf available january 20 with 4,289 reads how we measure reads. For the love of physics walter lewin may 16, 2011 duration. Jan 18, 2018 numerical results from response spectrum analyses were compared to corresponding time history analysis results to assess the accuracy of the various combination methods tested. These pseudovelocity and acceleration spectra are of the same physical interest but not an essential part of a response spectrum analysis.
Response spectrum analysis for irregular multistorey structure in seismic zone v. Highlights from chapter 12 of asce 716 provisions for. 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. It is part of the process of structural design, earthquake engineering or structural assessment and retrofit see structural engineering in regions where earthquakes are prevalent. Sep 10, 20 equivalent lateral force for an earthquake is defined as a set of lateral force which will produce the same peak response as that obtained by dynamic analysis of structures.
Learn about the sap2000 structural analysis and design program. Reevaluation of regulatory guidance on modal response. The significant difference between linear static and linear dynamic analysis is the level of the forces and their distribution along the height of structure. Earthquake response spectrum analysis of 4 story shear. It is practical to envelope response spectra such that a smooth curve represents the peak response for each realization of. Rcc buildings, equivalent static analysis, response spectrum analysis. Deformation cable supported bridge analysis and pushover analysis. Nov 22, 2017 equivalent static method esm and response spectrum method rsm both attempt to quantitatively estimate force due to an earthquake on a structure in terms of a set of static forces applied at specific points.
Response spectrum method of analysis with simplified. Described in sap2000 analysis reference manual page 1 to page 151 that is available in pdf format file name saprefer. Pdf response spectrum analysis of structures subjected to. Cold rolled steel design modal analysis, response spectrum, time history, linear and nonlinear analysis, pushover analysis, base. 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.
The results from the x, y, and zdirection analyses are tabulated below. To evaluate the seismic response of the buildings, elastic analysis was performed by using response spectrum method using the computer program sap2000. It can be passive response or active response but it doesnt matter. In speaking with the folks at sap2000, they indicated that their program takes the results of the modal response spectrum analysis mrsa, and converts it into an equivalent static load case so that the results can be combined with the direct analysis method dam, which is essentially what im after as this is brain damage to complete manually. The first version of this chapter on the response spectrum method was written. What matters is how the buildings respond to earthquakes. Effect of soilstructure interaction in seismic analysis of. What is difference between time history analysis and. While performing response spectrum analysis in sap2000.
Sap2000 watch and learn video tutorials cover a wide range of topics, from basic product overviews to advanced subjects such as nonlinear sequential construction. Response spectrum analysis of asymmetrical building. 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. Mass participation of second vertical mode is driving. Response spectrum analysis requires that isolator units be modeled using amplitude dependent values of effective stiffness. The reason we want to use a response spectrum is that it allows us to analyze transient events time based events without having. Pdf response spectrum analysis for irregular multistorey. Pdf response spectrum analysis for irregular multi. Seismic design of buildings worked examples worked examples presented at the workshop ec 8. The equivalence is restricted to a single mode of vibration. During responsespectrum analysis, loading is applied to the entire. How to implement a seismmodal response spectrum analysis.