It also plots the solution and stores them in a file allowing certain changes such as the acceleration unit. Sgs s eismic data g eneration s ystem extracts and plots graphs of earthquake history records, seismic response spectrums and design response spectrums using the midas family programs builtin earthquake database. An artificial accelerogram generator code written in matlab ferreira. Simulation of uniform hazard earthquake ground motions, journal of structural engineering, vol.
The response spectrum of an earthquake is the most favored seismic input for earthquake engineers. Its origin probably dates from civil engineering and the problem of seismic excitations, i. Aug 24, 2006 this program calculates the shock response spectrum for a base input, where the base input is in the form of an acceleration time history. Statistical earthquake ground motion models gavin and. Vibration response spectrum file exchange matlab central. There are a number of response spectra that are defined for representing the ground motion, such as, displacement response spectrum, pseudo velocity response spectrum, absolute acceleration response spectrum, and energy spectrum. Among the most important seismic parameters of a strong ground motion are the various types of spectra i. Ground motion estimation during strong seismic events using matlab. It provides a technique for performing an equivalent static lateral load analysis. T he response spectrum of an earthquake is the most favored seismic input for earthquake engineers. Locate and describe an earthquakes magnitude using matlab lets say a big earthquake occurs somewhere in the world and you want to know a bit about it. So, the hysteretic behavior of the soil is described using the shear. The course presents the response spectrum method of earthquake response analysis of simple structures and mechanicalelectrical equipment.
Strong motion recordings are the key in many earthquake. Sep 28, 2015 a new computerbased platform has been proposed whose novelty consists in modeling the local site effects of the ground motion propagation using a hybrid approach based on an equivalent linear model. Construction of design response spectrum the chilean way. This function generates elastic response spectrum for seismic design of buildings. During an earthquake, violent shaking is transmitted into a structure at the points where it is attached to the ground. Elastic response spectrum for elcentro earthquake california, may 18, 1940, ns component. Software to download usgs earthquake hazard program. Response spectrum analysis 7 the maximum ground acceleration, for the earthquake defined by figure 15. A computerbased environment for processing and selection of. This was then further developed into a design response spectrum for use in structural design, and this basic form. Ground motion estimation during strong seismic events using. Response spectra file exchange matlab central mathworks. Gismo toolbox seismic data analysis in matlab file.
The soil behavior is modeled assuming that both the shear modulus and the damping ratio vary with the shear strain amplitude. Response spectrum method of analysis with simplified. Figure 3 shows the lower half of the earthquake acceleration response spectrum that we will use for the analysis. It is apparent that all response spectrum curves represent the properties of the earthquake at a specific site and are not a function of the properties of the structural system. Response spectra are calculated for five damping periods 0, 2, 5, 10 and 20%. He defined the srs shock response spectrum as the maximum response motion from a set of single dof oscillators covering the frequency range. Shock response spectrum file exchange matlab central. 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. Study of earthquake response spectra submitted in partial fulfillment of the requirements of bits c421t. To design a structure against earthquake, one of the most recommended methods by design specifications is response spectrum analysis in which rather than time history analysis, maximum responses are estimated by this method. Project seizmo is a matlab and gnu octave based toolbox encompassing a collection of over 700 functions that provide a framework for seismic data preparation, quality control, and analysis akin to that of seismic analysis code with a focus on passive source seismology at regional and global scales where earthquakes and ambient noise are the. Earthquake analysis and design of simple structures and. Jennings abstract a numerical method for computing response spectra from strongmotion earthquake records is developed, based on the exact solution to the governing differential equation. Computer programs for calculating and optimization linear 1d.
An algorithm developed in matlab for the automatic selection of cut. An improved algorithm for selecting ground motions to match a. Locate and describe an earthquakes magnitude using matlab. This can be accomplished quickly by using broadband data from the iris dmc data management center and some coding in matlab. The chapter presents probabilistic methods for evaluating seismic risk at a site and development of seismic maps used in codes and provisions. The acceleration response spectra is represented as piecewise linear segments, whose endpoints are defined by a time, acceleration coordinate. Response spectrum is an important concept for the analysis of the dynamic effect of earthquake events. To do so, first, natural frequencies or period should be obtained by means of modal analysis of desired structure. It offers a simplified method for finding the design forces for structural members for. The following matlab project contains the source code and matlab examples used for response spectra. This script aims to offer the shock response spectrum of an acceleration time history of an earthquake which is known.
After an estimation is made of the linear viscous damping properties of the structure, a specific response spectrum curve is selected. Pdf this report is the development of response spectrum analysis for mdof structure in matlab. Seismic response spectrum gui file exchange matlab central. It also discusses some related issues, such as the response spectrum calculations, the statistical dependence between the three earthquake components, the duration of the time history, the. A verysmall matlab package that implements the empirical earthquake sourcescaling relations to enable monte carlo approach to predict the source parameters, i. Earthquake ground motion and response spectra springerlink. The method presented in the course is widely used and is applicable to any structure or equipment that can be modeled as a singledegreeoffreedom sdof system. The method presented in this course is widely used and is applicable to any structure or equipment that can be modeled as a singledegreeoffreedom sdof system. The response spectrum rather than seismological parameters ubc 1997 and ibc 2000 maximumstructural response if threerecords used averagestructural response if sevenrecords used srss of the two horizontal components should not be less than 1.
This script calculates the elastic response spectra based on eurocode 8 part1 en 19981. From this, you can see how the toolbox starts life as a collection of useful stuff from a small group, into a mature, wellthought out collection of tools meant for use by a broader audience. The base input psd must be in terms of acceleration. This paper presents statistical models for the generation of biaxial earthquake ground motion time histories with spectra that match those from samples of ground motion records. A displacement response spectrum is the plot of maximum displacement of a single degree of freedom system sdof to a particular ground motion as a function of the natural frequency and damping ratio of the sdof.
Gismo is a matlab toolbox for seismic data analysis built on a common platform. Spectrum intensity is defined as the integral of pseudovelocity spectrum of 5% damping level between 0. Elastic response spectrum file exchange matlab central. Earthquake design spectra given a earthquake ground acceleration, there is no difficulty to compute response using newmarks method as the previous example. Sep 16, 2011 the response spectrum of an earthquake is the most favored seismic input for earthquake engineers. It allows a clear understanding of the contributions of different modes of vibration. 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. We are interested in the maximum relative displacement, velocity, and total accelerations. Constant ductility response spectrum for elcentro earthquake california, may 18, 1940, ns component chopra 2012. To solve the equation of motions for different periods, the newmark linear method was used.
In the context of seismic analysis of structures, various earthquake inputs may be required depending upon the nature of analysis being carried out. This spectrum were done taking as a start point normalized version of the response spectra obtained from different accelerograms recorded for the following earthquakes. Factors that influence earthquake ground motion such as source distance, site geology, earthquake magnitude, source characteristics, and directivity are examined. In particular, gismo provides a framework that speeds the development time for building research codes around seismic waveformtrace data, event catalog data and instrument responses. Engineers use response spectrum modal superposition analysis to determine the structural response to sudden forces or shocks such as an earthquake. Response spectrum analysis is the dominant contemporary method for dynamic analysis of building structures under seismic loading. Earthquake response spectrum analysis of 4 story shear. The main reasons for the widespread use of this method are. In the 1982 eeri monograph on earthquake design and spectra, newmark and hall describe how they developed an idealized seismic response spectrum based on a range of response spectra generated for available earthquake records. Aug 24, 2006 this program calculates the vibration response spectrum vrs for a base input power spectral density psd. Biots apparatus consisted of a set of torsion pendulum which simulated mechanical systems with one degree of freedom 3. A new opensource software for strong ground motion data processing.
I have more of these types of programs for shock and vibration, so please let me know if there is an interest. Therefore, it enables the user to calculate the peak ground acceleration pga and pseudo velocity. Therefore, we can generate a response spectrum for that earthquake. For an entertaining and enlightening history of the toolbox, i encourage you to read this post from celsos blog. The user can change the input parameters to construct a sitespecific response spectrum considering different hazard conditions.
The vrs uses pointbypoint multiplication of the transmissibility function times the base input psd. Shock response spectrum srs in matlab mathworks, inc. The shock response spectrum srs allows to estimate transient acceleration signals in terms of a maximum response of a dynamic vibration system. Response spectra in matlab download free open source matlab. This online engineering pdh course presents the response spectrum method of earthquake response analysis of simple structures and mechanicalelectrical equipment. Gupta group leader, civil engineering group birla institute of technology and science pilani, rajasthan333031. It determines the response spectrum of accelerations, pseudoaccelerations, displacements, velocities and pseudovelocities, for an accelerogram, by means of matlab program with input file in.
782 333 910 477 168 978 1484 398 271 678 368 1220 216 895 606 972 1362 873 1043 1551 1406 1053 442 931 1376 54 1014 1117 1141 1017 396 930 1414 1256 735 1484 1362 231