Calculation of the design response spectrum in terms of spectral acceleration representing the seismic action in the horizontal or vertical direction. The user can change the input parameters to construct a sitespecific response spectrum. These acceleration loads are applied at each node and object to simulate ground motion during timehistory and. Based on ansys software, the seismic analysis by the response spectrum method and time history method is performed, and the simulation results are compared, it can be concluded that the calculation results of the earthquake response peak values and the main response frequencies are comparable, the thyristor. A plot of the peak value of a response quantity eg. Response spectra are used in seismic design, for example, according to. A shock response spectrum is a useful tool for estimating the damage potential of a shock pulse, as well as for test level specification. Calculation of shock response spectrum jiri tuma1 and petr koci2 abstract. In this paper the 20 analysis methodology is extended to give isolation system designers a direct method of estimating structure lateral load demands and isolation displacement demands to a set of. T n plot the equal ductility response spectrum, log. Random run controlled spectrum random tests tests with a spectrally shaped gaussian amplitude distribution. Conversion of time history to response spectrum mechanical.
But that velocity is the maximum velocity that the structureor system will reach for each period. Therefore, we can generate a response spectrum for that earthquake. It is common that a response spectrum is specified by a graph consisting of straight lines in a loglog diagram. Design spectrum according to eurocode 8 rcsolver software.
An answer or a reaction to this vibration can be acceleration, a velocity or displacement. Constant ductility inelastic displacement response spectrum. Response spectrum analysis massachusetts institute of. Given a earthquake ground acceleration, there is no difficulty to compute response using newmarks method as the previous example. The maximum response plotted against of undamped natural period and for various damping values and can be expressed in terms of maximum absolute acceleration, maximum relative velocity or maximum relative displacement. The linear elastic response spectrum leresp for a response quantity acceleration, velocity, displacement, etc. Accelerationdisplacement response spectrum adrs illustration. Comparative study of static and dynamic seismic analysis of a. Elastic response spectrum file exchange matlab central. A shock response spectrum srs is a plot of the maximum excursions of a series of massspringdamper systems.
We are interested in the maximum relative displacement, velocity, and total accelerations. A residual displacement response spectrum is presented for design of a singledegreeoffreedom structures and a design application is also provided. The acceleration response spectrum of a ground motion is a relationship between the natural period of vibration of a sdof system and the maximum absolute acceleration that it experiences under the ground motion. The peak response is computed by one of several modal. The acceleration response spectrum of a ground motion is a relationship between the natural period of vibration of a sdof system and the maximum absolute acceleration that it experiences under. Anbazhagan4 1school of civil, mining and environmental engineering, university of wollongong, wollongong, australia 2 faculty of engineering and industrial sciences, swinburne university of technology, hawthorn, victoria, australia. This function generates elastic response specra including displacement spectrum, pseudo acceleration spectrum, and pseudo velocity spectrum which are needed in a response spectrum analysis of structures. Constant ductility inelastic displacement response. The average acceleration response spectrum of these records is shown in fig. Since one is the inverse of the other, the two graphs are just mirrored when plotting on a logarithmic scale. Neaz sheikh1, hingho tsang2, saman yaghmaeisabegh 3, p. Nx response simulation software is an addon module to the nx advanced.
Each linear elastic response spectrum is associated with a. Determination of standard response spectra and effective. The acceleration response spectrum of a ground motion is a relationship between the natural period of vibration of a sdof system and the maximum absolute acceleration that it. How to get vertical distribution of the total base shear in a response spectrum analysis. Macro for computation of acceleration, velocity and displacement response spectra posted july 8, 2018 july 9, 2018 amin the vba macro implemented in the enclosed spreadsheet calculates. A new opensource software for strong ground motion data processing. I am doing time history analysis using acceleration time history of gorkha earthquake2015, i am not clear about the response spectral matching with target response spectrum. Evaluation of damping modification factors for seismic. As it is stated in the iso 184314 standard, a shock response spectrum is defined as the response to a given acceleration acting at a set of massdamperspring oscillators, which are adjusted to. A response spectrum is a graphical relationship of maximum values of acceleration, velocity, andor displacement response of an infinite series of elastic single degree of freedom sdof systems subjected to. The typical earthquake ground motion response spectrum represents an envelope of the peak responses of many singledegreeoffreedom sdof systems with different periods.
This file can be used as input file to the qsrs and arbit programs. Originally, when we were studying the dynamics of a simple single degree of freedom structure, we noticed that given one type of earthquake, we dont have to keep solving the equat. The displacement, velocity, and acceleration response spectra are defined as the maximum values caused by the acceleration history. In the present paper, nonlinear time history and response spectrum analyses were carried out using etabs2015 software to study the influence of soil condition beneath the isolated base.
It was adopted by the military after biotmit utilized srs algorithms to develop qualification tests for navy equipment. Oct 12, 2019 the function generates pseudospectral acceleration psa, pseudospectral velocity psv and spectral displacement sd spectra for given damping ratio e. Spectral acceleration sa is a unit measured in g the acceleration due to earths gravity, equivalent to gforce that describes the maximum acceleration in an earthquake on an object specifically a damped, harmonic oscillator moving in one physical dimension. To solve the equation of motions for different periods, the newmark linear method was used. This can be measured at or specified for different oscillation frequencies and with different degrees of damping, although 5%. A response spectrum is a graphical relationship of maximum values of acceleration, velocity, andor displacement response of an infinite series of elastic single. 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.
How global reaction and global base shear are different. Damping modification factors for acceleration response. A response spectrum is a plot of the peak values of the response displacement, velocity, or acceleration of a number of sdof systems with different natural vibration periods subjected to the same seismic i nput. Jul 08, 2018 macro for computation of acceleration, velocity and displacement response spectra posted july 8, 2018 july 9, 2018 amin the vba macro implemented in the enclosed spreadsheet calculates. Spectral acceleration, velocity and displacement spectra.
Residual displacement response spectrum journal of. So if you have a spectrum of displacement for a particular modelloading, this means that for a model that has a period of 0. Hi, i want to convert a time history record of an earthquake into a response spectrum. Construction of design response spectrum the chilean way eps 256. For this purpose response spectrum case of analysis have been performed according to is 1893. 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. Sample acceleration time history from pyrotechnic shock event. I am aware of the theory behind this but would like to locate software that can do it for me without setting out to write something myself. A response spectrum is a plot of the peak values of the response displacement, velocity, or acceleration of a number of sdof systems with different natural vibration periods subjected to the same seismic i. Eurocode 8 design acceleration response spectrum for design of ductile structures in the inelastic range with the behavior factor q description. Comparative study of static and dynamic seismic analysis.
This research is part of a national research program on the development of seismic retrofit solutions for multistorey buildings in new zealand frst retrofit, 2009. Apr 09, 2016 a velocity response spectrum is a graph of velocity versus period. Responsespectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration, velocity, or displacement as a function of. Csi software automatically generates and envelopes a set of acceleration loads for translation along, and rotation about, each global axis.
Software to download usgs earthquake hazard program. Response spectrum analysis definition comsol multiphysics. Selecting the type of design response spectrum and its definition. A velocity response spectrum is a graph of velocity versus period. Design response spectra are often provided in terms of the period, rather than the frequency.
Response spectra vol 5 response spectra of relative displacement, relative velocity, pseudovelocity, and absolute acceleration are computed for damping values of 0, 2, 5, 10 and 20 percent. Calculation of acceleration, velocity, and displacement response histories. The resulting plot can then be used to pick off the response of any linear system, given its natural frequency of oscillation. Determination of standard response spectra and effective peak.
Responsespectrum analysis technical knowledge base. The vibration response spectrum is particularly suited for random vibration inputs. Nx response simulation siemens digital industries software. The software system receives the acceleration data from a lower computer, then processes the data and uses fft and shock response spectrum srs to judge shock test result. Rfstttresponse of structures to earthquake ground motions. Applicable for the design of ductile structures where the inelastic behavior is taken into account explicitly with the behavior factor q. It is practical to envelope response spectra such that a smooth curve represents the peak response for each realization of. The function generates pseudospectral acceleration psa, pseudospectral velocity psv and spectral displacement sd spectra for given damping ratio e.
Construction of design response spectrum the chilean way. Conversion of time history to response spectrum electricpete electrical 1 jun 09 11. To enter a response spectrum, you add it as a function under global definitions. It is possible to do a similar definition of the absolute spectra, by instead using the absolute displacement. A base with massspringdamper systems distributed across it is only used to illustrate how the calculation works. For the shock response spectrum calculation, vibration is measured only at one location. 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. Elastic spectrum ec in the horizontal direction for a damping of 5% fardis, 2009a in the areas of fixed spectral acceleration, velocity, and displacement, the design spectrum originates from an elastic response with a 5% damping divided by q. Response spectrum analysis is a method for estimating structural. Enter two values out of the four between acceleration, frequency, velocity, or displacement, and the calculator will do the rest. Software for generation of spectrum compatible time history.
Based on ansys software, the seismic analysis by the response spectrum method and time history method is performed, and the simulation results are compared, it can be concluded that the calculation results of the earthquake response peak values and the main response frequencies are. It applies an acceleration time history as an excitation to an array of singledegreeoffreedom sdof systems. Conversion of earthquake acceleration data to pseudo. This algorithm requires four time history analyses to initialize the iterations for the. Shock response spectrum srs shock response spectrum is an accepted tool for developing laboratory shock tests. Response spectrum dictionary containing all response spectrum. The shock response spectrum is a calculated function based on the acceleration time history. Effect of soil condition on seismic response of isolated. Displacement and acceleration design spectra for seismic. Acceleration, velocity and displacement spectra omega arithmetic prosig signal processing tutorials 5 0 2 4 accel msec. Spectral ordinates are for linearelastic singledegreeoffreedom system with unit mass.
How to perform structural analyses using shock response spectra. Acceleration, velocity and displacement spectra arithmetic. This function gives the rootmeansquare response of each system to an acceleration base input. Macro for computation of acceleration, velocity and. The design response spectrum is the actual input to the response spectrum analysis. First off, a spectrum is a grouping of the maximum response of many analysis. The resulting plot can then be used to pick off the response of any linear system, given its natural frequency of. Calculation of the elastic response spectrum in terms of spectral acceleration and spectral displacement representing the seismic action in the horizontal or vertical direction. The srs technique is a straightforward way to characterize a shock environment. The effects of soil flexibility are considered in the current study to examine the differences in spectral acceleration, base shear, story displacements, story drifts and story shear obtained following the.
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