Mass participation factor in sap2000 manual pdf

Advanced applied load options have been added for multistep static load cases. For modal response history analysis, sap2000 allows an explicit damping. Csi analysis and reference manual for sap2000, etabs and safe 2. Modal participation factor and modal mass coefficient for the first natural mode in sap 2000 shz7 structural 6 jun 17 02. How do i calculate the fixed mass participation ratio of the model. Additionally, we can represent that information graphically to facilitate the visualitation there is only a representation of the first 80th modes. A new nonlinear multistep static load case type has been added. Sap2000 has a powerful design in steel, concrete and aluminum fully integrated, all available from the same interface used to model and analyze the model. As the modal mass participating factor is more than 75% in the higher mode, the considered structure is stiff for earthquake excitation. Modal mass k modal stiffness k g modal geometric stiffness f,f force or force vector f frequency z angular frequency participation factor p effective mass a dynamic amplification d,e rayleigh damping coefficients damping ratio in general scalar quantities are denoted by italics e. Modal mass coefficient and modal participation factor in.

Mini sap 2000 tutorial for an example beam hands on. In addition, static and dynamic participation factors have been defined that allow the structural. Guidelines and tutorial for modeling haunched steelgirder bridges. The fixed mass participation ratio may be calculated as follows. After running modal analysis, modal mass participation can be checked in etabs. Demonstration of dynamic lateraltorsional coupling in building structures ucla pxt, pyt, p. Csi etabs 11 modal analysis case eigen or ritz vectors for fundamental time periodfrequency duration. Concerning analysis with sap2000 and abaqus software. Mass participation ratio technical knowledge base computers. A detailed and extensive procedure which describes the modeling, analysis, and design of a 3d steelframe pipe rack system. It is strongly recommended that you read this manual and work the tutorial before attempting a real project using sap2000.

Export the joint masses table to excel by selecting analysis results joint output joint masses sum all joint masses to find the total mass square the participation factor table and divide this value by total mass. How do i calculate the fixedmass participation ratio of the model. But if the first six modes only contribute 60% mass participation, and above 12 th mode also if for mode the mass participation factor is higher should we check with compressor harmonics upto that or not. Modal participation factor and modal mass coefficient for.

Sap2000 training manual civil engineering community. The following guidance is for elastic dynamic analysis. And the software will limit it to that many number of modal r. However, in many cases the users manual does not clearly. Mass participation factor and its role in modal anlysis.

You can change the units you are working with at any time and sap2000 will handle the conversion. Modal mass coefficient and modal participation factor in sap2000. For example, asce 705 710 is at home, sorry, section 12. Fourth, the 90 percent mass participation rule, intended to assure accuracy of. Demonstration of lateraltorsional coupling in building. Lin ear and non lin ear static and dy namic anal y sis and. My guess is that ux, uy, and uz represent the mass participation of the translational mass. Example of how to use the mass participation factor in. Users manual, online documentation help, dassault systemes usa. To identify the dimensionless parameters governing the coupled lateraltorsional response of the system, equation 2 can be rewritten as note that ey px p. My doubt is that modal mass coefficient and participation factor as per atc 40 are unitless values. Ive modeled a simple 2 dof structure in etabs then manually computed the. Threedimensional static and dynamic analysis of structures.

Optimized modeling and design of structures using sap2000 presented by. My doubt is that modal mass coefficient and participation factor as per atc 40 are. Interpreting the modal mass participating ratios table from etabs posted on october 8, 2018 march 14, 2019 by engr dennis mercado i have not been modelling extensively in etabs this recently so this query from a former had my technical engine humming once more. How to calculate the relative contribution of each mode in. Sap90, sap2000, safe, floor and etabs are trademarks of. Building is required to be provided with moment resisting frames detailed as per is. It has even been codified in many of the codes of record. Sap2000 tutorials training videos, manuals and model files 38 gb civil engineering community from. Description and users guide, university of california, berkeley, ca. If modes 3, 6, 8 and 10 look like torsional modes, then this would probably confirm my assumption.

The modal participation factor i for mode i is mo ii li i 26 the modal participation vector is thus. Turkish ts 5002000 r2018, mexican rcdf 2017, australian as 36002018 and korean kbc 2016. Example i general modeling techniques 2d shear wall analysis. Being an office building, the importance factor, i, is 1.

The modal mass participation ratio is widely used as the metric to determine the relative significance of modes in a modal response spectrum analysis. For the love of physics walter lewin may 16, 2011 duration. The fixedmass participation ratio may be calculated as follows. The modal participation factor matrix i for mode i is m. Check the mass participation to see if enough modes were included in the solution. These parameters are used in the determination of the factor phib which eventually is used in the interaction equations eqn. Pdf response spectrum analysis for irregular multi. This should give you consistent modal participation factors. Pushover analysis of steel structure using staad tn. Seismic design of buildings worked examples worked examples presented at the workshop ec 8. Steel frame design manual which installs with each version of.

Seismic code requirements ucla henry samueli school of. The allowable story drift should be greater than or equal to the design story drifts for each floor level. This tutorial provides an introduction to the assignment of joint patterns. Sap2000 is a registered trademark of computers and structures, inc. The third part of this volume, the sap2000 introductory tutorial manual, is intended to provide firsttime users with handson experience using the modeling, analysis and design features of sap2000. Ppt pushover analysis powerpoint presentation free to. Interpreting the modal mass participating ratios table.

Why does sap2000 divide the responses of structures into. Till now we are not considering the mass participation factor for targeting the modes. The displacement demand of a 4story frame was 170 mm with a scale factor of 1. Sap2000 tutorial manual 3 building the model in sap2000 using templates 1. The effective modal mass provides a method for judging the significance of a vibration mode.

I believe the current version of sap2000 explicitly calculates this and you may find. The design of aluminum and steel members permits initial sizing and an interactive optimization and design of concrete elements includes calculating the required number of steel reinforcing. Sap2000 manual sap2000 is a program developed by the company csi, computer and structures, inc. Select the units you want to work with from the status bar at the bottom of the sap2000 window.

Square the participation factor table and divide this value by total mass. Modes with relatively high effective masses can be readily excited by base excitation. Because the default number of mode shapes entered in sap2000 are 12. 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. Local modes may disrupt the modal mass participation mode shapes. Go into define load cases modal cases define modal case change the number of mode shapes you want to consider.

Learn about the sap2000 structural analysis and design program. Under drift check, there are two checks to consider. As you said in sap2000 display tables, it gives the participation factors which is true but it. Effects of plastic hinge properties in nonlinear analysis. The sap2000 program is one of the leading structural engineering software. This allows the same link property to be used for multiple link objects that may, for example, represent different size. 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.

Mass participation zthe force participation of each mode can be gauged by the mass participation factor. Scaling factor for each ground motion should not be greater than 8. Calculated story drift using the maximum inelastic response displacement. Risa3d rapid interactive structural analysis 3dimensional version 7. As you said in sap2000 display tables, it gives the participation factors which is. Earthquake analysis with sap2000 earthquake analysis with sap2000 prepared by. If so, then rx, ry and rz would likely represent the mass particiaption of the rotational mass moment of inertia. Modal periods and frequencies are compared in the following table 2. Start up screen of sap2000, select working unit to be tonm at dropdown menu.