85M102006D

Seismic Analysis for a Turbine Building with Spring Supported Turbine / Generator Deck Feifei Lu, PE Shaw Power Group, Charlotte, NC June 23, 2011

85M102006D Topic Outline Overall Introduction –Turbine building –Spring and damper device Method Discussion Results Comparison Conclusion MathCad Application

85M102006D Background Introduction steel framing structure EBF & SCBF eccentrically braced frame (EBF) below the Turbine operating deck and special concentric braced frame (SCBF) above the operating deck

85M102006D Background Introduction Turbine Building: structural steel frame First-Bay: concrete structure Foundation: 6 feet deep reinforced concrete foundation mat

85M102006D Spring & Damper Device

85M102006D Spring Pedestal Design Basis Benefits of spring pedestal: Seismic Isolation of TG Vibration isolation of TG Generic site design

85M102006D Spring Devices Stiffness matrix is used to model each spring device. (Ref. GT STRUDL Vol.1 Section ) Horizontal spring matrix and Vertical spring matrix GT STRUDL Input:

85M102006D Damper Devices Viscous Damper Element is used to model the damper devices. (Ref. GT STRUDL Vol.3 Section ) GT STRUDL Input:

85M102006D Method discussion Method 1: Weighted Average Composite Modal Damping Method 2: Viscous Damper Element with Rayleigh Proportional damping (Ref. GTStrudl Damping Models for Dynamic Analysis by Dr. Swanger)

85M102006D Method discussion (Method 1) Method 1: Weighted Average Composite Modal Damping (Ref. NRC REGULATORY GUIDE 1.61 : DAMPING VALUES FOR SEISMIC DESIGN OF NUCLEAR POWER PLANTS)

85M102006D Method discussion (Method 1) Based on viscously damped free vibration (Ref. Dynamics of Structures Theory and applications to Earthquake Engineering, Second Edition, By Anil K. Chopra) Therefore, ζ =

85M102006D Method discussion (Method 1) Sample calculation:

85M102006D Method discussion (Method 1) GT STRUDL Input: CONSTANT MODAL DAMPING PROPORTIONAL TO STIFFNESS 0.04 MEMBERS… $ ( All Steel member) MODAL DAMPING PROPORTIONAL TO STIFFNESS 0.07 MEMBERS… $ ( All Concrete member) $ SPRING DAMPER MODAL DAMPING PROPORTIONAL TO STIFFNESS MEMBERS … $ (Horizontal springs) MODAL DAMPING PROPORTIONAL TO STIFFNESS MEMBERS … $ (Vertical springs) …… COMPUTE MODAL DAMPING RATIOS AVERAGE BY ELEMENT ……

85M102006D Method discussion (Method 2) Rayleigh damping value for the rest of the structure is calculated based on the classic Rayleigh damping method. (Ref. GTStrudl Damping Models for Dynamic Analysis by Dr. Swanger)

85M102006D Method discussion (Method 2) GT STRUDL Input: CONSTANT DAMPING PROPORTIONAL TO STIFFNESS 3.36E-3 MASS …… …… COMPUTE MODAL DAMPING RATIOS PROPORTIONAL BY ELEMENT

85M102006D Response Spectrum UBC 1997 Typical Design Response Spectrum - 5% of Critical Damping Ref. "Fundamentals of Earthquake Engineering", Elnashai, Amr, and Di Sarno, Luigi-Wiley 2008, pp. 242.

85M102006D Response Spectrum

85M102006D Results (Mode Shape)

85M102006D Results (Mode Shape)

85M102006D Results (Mode Shape)

85M102006D Results (Model Damping)

85M102006D Results (Displacement) Method 1 Method 2 ****SUMMARY OF MAXIMUM GLOBAL DISPLACEMENTS**** INDEPENDENT IN EACH COORDINATE ============================================= * RESULT * MAXIMUM LOAD JOINT * *========*==================================* * X-DISP * E JCON685 * * Y-DISP * E J * * Z-DISP * E J * ============================================= ****SUMMARY OF MAXIMUM GLOBAL DISPLACEMENTS**** SRSS VECTOR LENGTHS =============================================== * RESULT * MAXIMUM LOAD JOINT * *==========*==================================* * XYZ-DISP * E J * * XY-DISP * E J * * XZ-DISP * E JCON685 * * YZ-DISP * E J * =============================================== ****SUMMARY OF MAXIMUM GLOBAL DISPLACEMENTS**** INDEPENDENT IN EACH COORDINATE ============================================= * RESULT * MAXIMUM LOAD JOINT * *========*==================================* * X-DISP * E JCON685 * * Y-DISP * E J * * Z-DISP * E J * ============================================= ****SUMMARY OF MAXIMUM GLOBAL DISPLACEMENTS**** SRSS VECTOR LENGTHS =============================================== * RESULT * MAXIMUM LOAD JOINT * *==========*==================================* * XYZ-DISP * E J * * XY-DISP * E J * * XZ-DISP * E JCON685 * * YZ-DISP * E J * ===============================================

85M102006D Results (Force in Spring Device) X-dir RS analysis results Method 1Method 2Difference SpringX (kips)Y (kips)Z (kips)X (kips)Y (kips)Z (kips)XYZ SPR %1.53%3.26% SPR %1.53%3.26% SPR %1.52%3.26% SPR %1.52%3.26% SPR %1.55%3.26% SPR %1.55%3.26% SPR %1.55%3.25% SPR %1.55%3.25% SPR %1.52%6.77% SPR %1.52%6.76% SPR %1.52%6.75% SPR %1.52%6.74% SPR %1.53%6.73% SPR %1.53%6.72% SPR %1.53%6.72% SPR %1.53%6.72%

85M102006D Results (Force in Spring Device) Y-dir RS analysis results Method 1Method 2Difference SpringX (kips)Y (kips)Z (kips)X (kips)Y (kips)Z (kips)XYZ SPR %4.84%1.05% SPR %4.90%1.05% SPR %4.96%1.05% SPR %5.02%1.05% SPR %5.17%1.05% SPR %5.33%1.05% SPR %5.49%1.05% SPR %5.66%1.05% SPR %5.18%1.25% SPR %5.18%1.25% SPR %5.18%1.25% SPR %5.19%1.25% SPR %5.22%1.25% SPR %5.28%1.25% SPR %5.36%1.25% SPR %5.45%1.25%

85M102006D Results (Force in Damper Device) Damper element force Calculation Each mode V i = V ia -V ib By ABS method V = | | Force: F = c * V

85M102006D Results (Force in Damper Device) Damper element force Calculation RMS Velocity Summary (ft/s) Force (Kips) Damper Translational XYZXYZXYZXYZ 301 B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C B/C

85M102006D Conclusion Spring device and damper device can be successfully modeled in GT STRUDL. Both methods give results consistent with each other. To achieve more accurate results, time history analysis needs to be performed.

85M102006D MathCad Application  Benefits: Efficiency and Automation Generate load combination input file from Excel file. Transform structural coordinates to move and rotate structure geometry. Offset mass distribution to create 5% torsional seismic effect for response spectrum analysis.

85M102006D Load Combination  Example: Input file (Excel file)

85M102006D Load Combination  Example: MathCad file Example: MathCad file

85M102006D Load Combination  Example: Output file (txt file)

85M102006D Transform Structure  Modular Stair Tower.pps Modular Stair Tower.pps  Coordinate Transformation Function.html Coordinate Transformation Function.html  Original purpose of using MathCAD to transform structure is to simulate the process of rigging and installing stair tower module. Same as the “MOVE OBJECT” command. (Why not use “MOVE OBJECT” ? )  Later on, it is found this little program is very useful to transform any structure and combine structures in different orientation and origins together.

85M102006D Transform Structure 75 degree 90 degree

85M102006D Transform Structure 45 degree 60 degree

85M102006D Transform Structure 15 degree 30 degree

85M102006D Transform Structure Combine with TB Stairs Module

85M102006D Torsional seismic effect  The objective is to redistribute the structure's mass such that the requirements for accidental torsion are met.  At each level of the structure where it is desired to include accidental torsion, the mass will be re-distributed such that the new center of mass has been offset from its original position the required distance (normally 5% of the structures maximum dimension perpendicular to the direction of motion as code requirement).

85M102006D Torsional seismic effect SEISMIC LOAD.html Input: JC2.xls MASS DEAD2.xls Output: UBC-X-TOR.xls UBC-Y-TOR.xls

85M102006D Torsional seismic effect

85M102006D Acknowledgements The GT STRUDL analytical model used in this presentation is based on the Turbine Building for the Westinghouse AP1000 Advanced Passive Light Water Reactor Electric Power Generating Plant. Westinghouse Electric Company is the owner of the design. The original GT STRUDL analytical model was created by Toshiba Corporation/Obayashi Corporation in Japan. The design activity is being completed by Shaw under contract to Westinghouse. Dr. Michael Swanger Computer Aided Structural Engineering Center (GTSTRUDL) Structural Engineering, Mechanics, and Materials Georgia Institute of Technology

85M102006D References GT STRUDL User Reference Manual NRC REGULATORY GUIDE 1.61 Dynamics of Structures Theory and applications to Earthquake Engineering, Second Edition, Anil K. Chopra GTStrudl Damping Models for Dynamic Analysis, Michael H. Swanger, PhD Fundamentals of Earthquake Engineering, Elnashai, Amr, and Di Sarno, Luigi-Wiley 2008 UBC-1997

85M102006D Question ?