The theoretical background details and examples are included in the appendices. Base isolation of buildings with curved surface sliders. As you said in sap2000 display tables, it gives the participation factors which is true but it. The following guidance is for elastic dynamic analysis. You will be familiar with the mode shapes, mass participation, earthquake analysis, time periods etc.
The earthquake analysis capabilities of sap2000 are demonstrated using a railroad bridge bent designed in accordance with the arema manual for railway engineering. Interpreting the modal mass participating ratios table. However, the mass participation of subgrade levels may be. What is the difference between mass participation factor and mode participation factor. Ppt pushover analysis powerpoint presentation free to. Mass participation ratio technical knowledge base computers.
Effects of plastic hinge properties in nonlinear analysis. Before doing some modifications, the mass participation would reach 90 % from the 2nd mode. Hence, in this case, codal requirements on number of modes to be considered such that at least 90% of the total mass is excited, will be satisfied by considering the first mode of vibration only. This fully integrated product for the modeling, analysis and design of structures continues. Pushover analysis is a static, nonlinear procedure using simplified nonlinear technique to estimate seismic structural deformations. I believe the current version of sap2000 explicitly calculates this and you. Click save to save the listed information to an excel. You need to understand that this is not an easy to do course. She sent me the table below of the modal participating mass ratios extracted from etabs and asked whats wrong with her model.
Ive modeled a simple 2 dof structure in etabs then manually computed the. Start up screen of sap2000, select working unit to be tonm at dropdown menu. Sap2000 will do the stress checks automatically when a member is designed. Learn about the sap2000 structural analysis and design program. Modal participation factors are required to perform dynamic analysis and.
For example, asce 705 710 is at home, sorry, section 12. Modal participation factor and modal mass coefficient for. Sap2000 manual in spanish sap2000 portuguese guide sap2000 programme implementation manual sap2000 simplified bridge design manual sap2000 software verification sap2000 spanish manual sap2000 steel design manual sap2000 tutorial example analysis and design of continuous rc beam sap2000 tutorial structural analysis with sap2000 timehistory. When the responsespectrum curve is defined, acceleration is typically entered as a fraction of gravitational acceleration 9.
Structural software for analysis and design sap2000. Oct 14, 2014 the sap2000 program is one of the leading structural engineering software. Effects of plastic hinge properties in nonlinear analysis of. Mass participation zthe force participation of each mode can be gauged by the mass participation factor. I have not been modelling extensively in etabs this recently so this query from a former. Sap2000 is a registered trademark of computers and structures, inc. This should give you consistent modal participation factors. It comes in several versions standard, plus and advanced. Unsubscribe from computers and structures, inc sign in to add this video to a playlist. For dynamic cases, at least 90% mass participation in the x and y directions is required asce7. Why does sap2000 divide the responses of structures into 12. In my post example of how to use the mass participation factor in solidworks you can find a practical example where this methodology is. Modal analysis mass participation autodesk community.
These involve translations only in the two main directions, and the mass participation factor is very close to unity along the relative direction table 5. Aug 12, 2014 sap2000 is a program developed by the company csi, computer and structures, inc. You may understand that this is a section to refer in case, you are stuck with any case study. Now lets elaborate whats wrong, the seemingly wrong and the nothing. Therefore, pushover analysis with single load pattern may not yield correct results for a bridge model.
Due to its simplicity, the structural engineering profession has been using the nonlinear static procedure nsp or pushover analysis. Can sap2000 develop response spectra for a given location within. This section is not instructional and is not aimed at detailing the robot interface. As you said in sap2000 display tables, it gives the participation factors which is true but it is not unit less. The weight of the structure used in the calculation of automatic seismic loads is based on the specified mass of the structure. This email is an invitation for the participation in the first south asia conference on earthquake engineering sacee2019 which will be held on 2122 february 2019 in karachi, pakist. Modal participation factor and modal mass coefficient for the first natural mode in sap 2000 shz7 structural 6 jun 17 02.
Modal participation factors are required to perform dynamic analysis and response. Brick mansonry design in etabs journal articles tutorials. This allows the same link property to be used for multiple link objects that may, for example, represent different size. How to calculate mode shapes and frequencies in staad pro v8i using eigen extraction method. These parameters are used in the determination of the factor phib which eventually is used in the interaction equations eqn. The height hn is measured from the elevation of the specified bottom storyminimum elevation level to the top of the specified top storymaximum elevation level. As you said in sap2000 display tables, it gives the participation factors which is. Sap90, sap2000, safe, floor and etabs are trademarks of. The height hnismeasured from the elevation of the specified bottom storyminimumelevation level to the top of the specified top storymaximum elevationlevel. No matter what i do, tha mass participation ratio reaches a certain percentage 56% and stops increasing. After running modal analysis, modal mass participation can be checked in etabs. The fixedmass participation ratio may be calculated as follows.
Responsespectrum analysis faq technical knowledge base. Risa3d rapid interactive structural analysis 3dimensional version 7. Pdf format on the sap2000 dvd, and can also be accessed from within the program using. For static lateral cases, only the fundamental mode in the x and y directions is needed. Modal mass coefficient and modal participation factor in. Because the default number of mode shapes entered in sap2000 are 12. Modal participation factor and modal mass coefficient for the first natural mode in sap 2000 shz7 structural 19 feb 17 22. You can analyze any structures in this program, and even design element by element precisely with the known regulations aci in eu, rcdf in mexico, eurocode europe, etc.
However, in many cases the users manual does not clearly. Mehta gujarat state disaster management authority government of gujarat. Modal participation factor and modal mass coefficient for the. Fourth, the 90 percent mass participation rule, intended to assure accuracy of. Etabs mass participation ratios computers and structures. In addition, static and dynamic participation factors have been defined that allow the structural.
Most of the dynamic methods in robot are based on modal. This fully integrated product for the modeling, analysis and design of structures continues to be available in three levels. Introduction this document presents the description of the dynamic analysis methods applied in robot. How many modes should we consider in modal analysis of 7 storey 2d frame. Span bridges by multiple tuned mass dampers wind wizard workshop on tall building seismic design and analysis issues seismic design of building and bridges. Rightclick the results folder and select list mass participation figure 1. Threedimensional static and dynamic analysis of structures. Sap2000 follows in the same tradition featuring a very sophisticated, intuitive and versatile user interface powered by an unmatched analysis engine and design tools for engineers working on transportation, industrial, public works, sports, and other. I ve modeled a simple 2 dof structure in etabs then manually computed the. Check the mass participation to see if enough modes were included in the solution. Additional information is available in the csi analysis reference manual response spectrum analysis. Pushover analysis option will allow engineers to perform pushover analysis as per fema 356. Standard pushover analysis using fema 356 2000 displacement coefficient method and an improved upper bound pushover analysis method were used to analyse the building. The mass participation factors reported on the frequencies spreadsheet reflect how much each mode participated in the response spectra analysis solution.
You will also learn the basics of structural dynamics. According to etabs analysis reference manual ux uy uz rx ry rz are about the center of mass whatever that means. Oct 20, 2015 this page is devoted to frequently asked questions faq related to responsespectrum analysis. This page is devoted to frequently asked questions faq related to responsespectrum analysis. Sap2000 training manual civil engineering community. Sap2000 is a program developed by the company csi, computer and structures, inc. Go into define load cases modal cases define modal case change the number of mode shapes you want to consider. Mehta gujarat state disaster management authority government of gujarat strength stiffness deformability h. My doubt is that modal mass coefficient and participation factor as per atc 40 are unitless values. It expounds the main ideas realized in this program. Tutorial included in the sap2000 bridgeexamples document. For modal response history analysis, sap2000 allows an explicit damping.
Apr 23, 20 the height hnismeasured from the elevation of the specified bottom storyminimumelevation level to the top of the specified top storymaximum elevationlevel. Remember that the rsa involves calculating separately the response for each mode to the applied base excitation represented by the spectra. However, for illustration, solution to this example considers the first three modes of vibration. Etabs professional training for structural engineers udemy. The fixed mass participation ratio may be calculated as follows.
Seismic design of buildings worked examples worked examples presented at the workshop ec 8. Attached is a model file and a pdf which outlines the procedure for modeling. The sap2000 program is one of the leading structural engineering software. Modeling for such analysis requires the determination of the nonlinear properties of each component in the structure, quantified by strength and deformation capacities, which depend on the modeling assumptions. And the software will limit it to that many number of modal r. Modal mass coefficient and modal participation factor in sap2000.
Jun 08, 2011 unsubscribe from computers and structures, inc sign in to add this video to a playlist. Sap2000 watch and learn sap2000 tutorial videos sap2000 tutorial pdf sap2000 tutorial example sap2000 tutorial 3d frame sap2000 tutorial. The program starts with the period of the modecalculated to have the largest participation factor in the direction thatloads are being calculated x or y. The mass participation normalized dialog box opens. Sap2000, etabs and perform 3d, to undertake numerical. Sap2000 follows in the same tradition featuring a very sophisticated, intuitive and versatile user interface powered by an unmatched analysis engine and design tools for engineers working on transportation, industrial, public works, sports, and other facilities.
Simsolid fast start guide modal participation factors duration. Description and users guide, university of california, berkeley, ca. How many modes should we consider in modal analysis of 7. My doubt is that modal mass coefficient and participation factor as per atc 40 are.
Some concepts in earthquake behaviour of buildings c. Dynamics check modal participating mass ratios youtube. Export the joint masses table to excel by selecting analysis results joint output joint masses. Why does sap2000 divide the responses of structures into. Scale factor should be specified such that its product with responsespectrum values.
Sap2000 bridge tutorial pdf 7mb pdf concrete boxgirder, steelgirder, and cablestayed bridge tutorials. Square the participation factor table and divide this value by total mass. Pdf 38226024 etabs examples manual abdul raheem raheem. Theoretical basis of methods used during structure dynamic. The modal participation factor i for mode i is mo ii li i 26 the modal participation vector is thus.
The innovative enhancements in this version are categorized below. This conference is the inaugural event in this series of conferences which has been constituted under the auspices of south asia earthquake network shake. The modal mass participation ratio is widely used as the metric to determine the relative significance of modes in a modal response spectrum analysis. Sap2000 manual sap2000 is a program developed by the company csi, computer and structures, inc. C frame building it office, almora in sap 2000 v14 for the above stiffness mass matrices, eigen values and eigenvectors are, taking calculate eigen values calculate eigen vector calculate natural frequency in various modes calculate natural time period t calculate modal. This allows the same link property to be used for multiple link objects that may, for example, represent different size tributary regions supported by the link objects. The sap name has been synonymous with stateoftheart analytical methods since its introduction over 30 years ago. A 12span existing rc bridge was selected for the case study.
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