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*GTStrudl Version 30Response Spectrum Analysis EnhancementsRelated To

NRC Regulatory Guide 1.92, Revision 2

COMBINING MODAL RESPONSES AND SPATIAL COMPONENTSinSEISMIC RESPONSE ANALYSISMichael H. Swanger, Ph.D.Georgia Tech CASE Center

GTSUG 2008June 23-26, 2008Las Vegas, NV

*TopicsBackgroundNRC Reg Guide 1.92, Rev 1 PositionsResponse Spectrum CharacteristicsResponse Spectrum Solution StrategyNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum CharacteristicsResponse spectrum Solution Strategy

GTStrudl Enhancements, Version 30The RESPONSE SPECTRUM LOAD/MODE FACTORS CommandThe ALGEBRAIC Mode CombinationTotal Response

ExampleNRC Reg Guide 1.92 Rev 1 vs Rev 2

Background*

*Background

*BackgroundNRC Reg Guide 1.92, Rev 1 PositionsFrequencyAll modes are assumed to be out-of-phase with the ground acceleration and out-of-phase with each otherResponse Spectrum CharacteristicsAll modes having frequencies some arbitrary cutoff frequency are deemed significant for inclusion in the response spectrum analysisNote: 1976, the date of Reg 1.92, Rev 1, was prior to many of the significant developments in response spectrum analysis that we take for granted today!

*BackgroundNRC Reg Guide 1.92, Rev 1 PositionsResponse Spectrum Solution Strategy For each ground motion direction, k = 1, 2, 3, the modal maximum responses from all significant modes, having no time and phase characteristics, are combined according to a statistical rule, such as SRSS.

The total response is computed from the SRSS of the combined modal responses in each ground motion direction

*BackgroundNRC Reg Guide 1.92, Rev 1 PositionsResponse Spectrum Solution Strategy If frequencies are not closely spaced:

SRSS Mode Combination Method two consecutive modes are defined as closely spaced if their frequencies differ from each other by no more than 10 percent of the lower frequency

*BackgroundNRC Reg Guide 1.92, Rev 1 PositionsResponse Spectrum Solution Strategy If frequencies are closely spaced: NRC Grouping Method NRC Ten Percent Method NRC Double Sum Methodtd = duration of earthquake

*BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Characteristics F1=frequency at which peak spectral acceleration is observed

F2= frequency above which the SDOF (modal) oscillators are in-phase with the transient acceleration input used to generate the spectrum and in phase with each other

FZPA=frequency at which the spectral acceleration returns to the zero period acceleration; maximum base acceleration of transient acceleration input used to generate the spectrum

BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Characteristics fi F1Maximum response from periodic or transient response in the modal frequency fi. Maximum modal (oscillator) responses are out-of-phase with one another.*

BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Characteristics *FrequencyLow FrequencyOut-of-PhaseResponseMid FrequencyTransition fromOut-of-Phase toIn-Phase ResponseHigh FrequencyIn-Phase Rigid StaticResponse fi F2Maximum response from steady state response. The maximum modal responses are in phase with one another.

F1 < fi < F2Response is part periodic and part rigid. Maximum modal responses transition from out-of-phase to in phase.BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Characteristics FrequencyLow FrequencyOut-of-PhaseResponseMid FrequencyTransition fromOut-of-Phase toIn-Phase ResponseHigh FrequencyIn-Phase Rigid StaticResponse*

*BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Solution Strategy For each mode i, in each ground motion direction k, the response is separated into a periodic part and a rigid part: The periodic modal response portions are combined using a double sum rule:

*BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Solution Strategy The rigid modal responses are combined algebraically,including the residual rigid contribution from the missing mass: The total response in each ground motion direction is computed from the SRSS of the modal combinations of the periodic and rigid responses:

*BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Solution Strategy Finally, the complete response is computed by performing the SRSS on the total responses in the three ground motion directions:A 100-40-40 rule is also acceptable for combination of the spatial response components

*BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Solution Strategy Computation of rigid response factor ki ; The Gupta Method:FrequencyLow FrequencyOut-of-PhaseResponseMid FrequencyTransition fromOut-of-Phase toIn-Phase ResponseHigh FrequencyIn-Phase Rigid StaticResponse

BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Solution Strategy Periodic responses are combined using a double sum rule:ij computed according to the following methods:

SRSS Method NRC Double Sum Method (Rosenbleuth correlation coefficient) CQC method (Der Kiureghians correlation coefficient)*

*BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Solution Strategy Computation of the Residual Rigid Response for allfi FZPA by the Missing Mass Method:The Missing Mass Method is quite accurate and is most important for adequately capturing the high-frequency response near supports

*BackgroundNRC Reg Guide 1.92, Rev 2 PositionsResponse Spectrum Solution Strategy Note:Under Rev 2, the response spectrum solution also may be performed according to Reg 1.92, Rev 1 provided that the residual rigid response due to the missing mass is included

*GTStrudl Enhancements, Version 30RESPONSE SPECTRUM LOAD/MODE FACTORS Command Purpose:To compute and (1 2)1/2 for each active mode for the defined response spectrum load Syntax

*GTStrudl Enhancements, Version 30RESPONSE SPECTRUM LOAD/MODE FACTORS Command ExampleUNITS CYCLES SECONDSRESPONSE SPECTRUM LOAD 100RSUPPORT ACCELERATION TRANSLATION X 1.000000 FILE ELC-RS MODE FACTORS COMPUTE RIGID RESPONSE FZPA 40.0END RESPONSE SPECTRUM LOAD

RESPONSE SPECTRUM LOAD 100PSUPPORT ACCELERATION TRANSLATION X 1.000000 FILE ELC-RS MODE FACTORS COMPUTE PERIODIC RESPONSE FZPA 40.0END RESPONSE SPECTRUM LOADNote: FZPA is specified (FZPA 40.0); therefore:F1 = Samax/(2Svmax) F2 = (F1 + 2FZPA)/3

*GTStrudl Enhancements, Version 30The ALGEBRAIC Mode Combination

*GTStrudl Enhancements, Version 30The ALGEBRAIC Mode Combination ExampleLOAD LIST 100R $ Rigid RS ComponentsCOMPUTE RESPONSE SPECTRUM DISPLACEMENTS MODE COMBINATION ALGEBRAICCOMPUTE RESPONSE SPECTRUM FORCES MODE COMBINATION ALBEGRAICCREATE PSEUDO STATIC LOAD PS100R FROM ALGEBRAIC OF LOAD 100R...

LOAD LIST 100P $ Periodic RS ComponentsCOMPUTE RESPONSE SPECTRUM DISPLACEMENTS MODE COMBINATION CQCCOMPUTE RESPONSE SPECTRUM FORCES MODE COMBINATION CQCCREATE PSEUDO STATIC LOAD PS100P FROM CQC OF LOAD 100P

*GTStrudl Enhancements, Version 30Total Rigid, Directional, and Solution Response Example$* **$* ** Total Rigid Response$* **UNITS CYCLES SECONDSFORM MISSING MASS LOAD 100M FROM RESPONSE SPECTRUM LOAD 100R CUTOFF FREQUENCY 40.0 . . .

STIFFNESS ANALYSIS

CREATE LOAD COMBINATION 100RTOT SPECS PS100R 1.0 100M 1.0

$* **$* ** Total Directional Response$* **CREATE LOAD COMBINATION 100TOT TYPE RMS SPECS PS100P 1.0 100RTOT 1.0 . . .

$* **$* ** Total Solution Response$* **CREATE LOAD COMBINATION EQTOT TYPE RMS SPECS -100TOT 1.0 200TOT 1.0 300TOT 1.0

*Example 1(4 @ 10)(5 @ 10)(6 @ 12)Columns: W14X53Beams (Global X): W18X35Beams (Global Z): W18X50210 Joints, 474 MembersAdditional Mass: 1 kip, all joints, Global X and Z

Seismic Loading: El Centro RS, Global X and Z

Example 1El Centro Response Spectrum UNITS FEET CYCLES SECONDSCREATE RESPONSE SPECTRUM ACCELERATION - LINEAR VS FREQUENCY LINEAR FILE 'ELC-RS' FREQUENCY RANGE FROM 0.10000 TO 60.00000 AT 0.10000 DAMPING RATIOS 0.05 USE ACCELERATION TIME HISTORY FILES 'ELCENTRO' INTEGRATE USING DUHAMEL DIVISOR 20.00000END OF CREATE RESPONSE SPECTRUMF1 = 1.9 HZF2 = 27.3 HZFZPA*

Example 1Revision 1Revision 2UNITS INCHES KIPSDEAD LOAD 'DLX' DIR X ALL MEMBERSDEAD LOAD 'DLZ' DIR Z ALL MEMBERSINERTIA OF JOINTS FROM LOAD 'DLX' SAME DOFSINERTIA OF JOINTS FROM LOAD 'DLZ' SAME DOFSINERTIA OF JOINTS WEIGHT EXISTING TRANSL X 1.0 Z 1.0

UNITS CYCLES SECONDSEIGENVALUE PARAMETERS SOLVE USING GTSEL FREQUENCY SPECS 0.0 TO 40.0 PRINT MAXEND

DYNAMIC ANALYSIS EIGENVALUEUNITS INCHES KIPSDEAD LOAD 'DLX' DIR X ALL MEMBERSDEAD LOAD 'DLZ' DIR Z ALL MEMBERSINERTIA OF JOINTS FROM LOAD 'DLX' SAME DOFSINERTIA OF JOINTS FROM LOAD 'DLZ' SAME DOFSINERTIA OF JOINTS WEIGHT EXISTING TRANSL X 1.0 Z 1.0

UNITS CYCLES SECONDSEIGENVALUE PARAMETERS SOLVE USING GTSEL FREQUENCY SPECS 0.0 TO 40.0 PRINT MAXEND

DYNAMIC ANALYSIS EIGENVALUE*

Example 1Revision 1Revision 2$* **$* ** Define response spectrum loads for rigid response in$* ** the global X and Z directions$* **RESPONSE SPECTRUM LOAD 100R'SUPPORT ACCELERATION TRANSLATION X 1.000000 FILE 'ELC-RS' MODE FACTORS COMPUTE RIGID RESPONSE FZPA 40.0END RESPONSE SPECTRUM LOAD

RESPONSE SPECTRUM LOAD 300R'SUPPORT ACCELERATION TRANSLATION Z 1.000000 FILE 'ELC-RS' MODE FACTORS COMPUTE RIGID RESPONSE FZPA 40.0END RESPONSE SPECTRUM LOAD

$* **$* ** Define response spectrum loads for periodic response$* ** in the global X and Z directions$* **RESPONSE SPECTRUM LOAD 100P'SUPPORT ACCELERATION TRANSLATION X 1.000000 FILE 'ELC-RS' MODE FACTORS COMPUTE PERIODIC RESPONSE FZPA 40.0END RESPONSE SPECTRUM LOAD

RESPONSE SPECTRUM LOAD 300P'SUPPORT ACCELERATION TRANSLATION Z 1.000000 FILE 'ELC-RS' MODE FACTORS COMPUTE PERIODIC RESPONSE FZPA 40.0END RESPONSE SPECTRUM LOAD

UNITS INCHES KIPS CYCLES SECDAMPING RATIOS 0.05 100

PERFORM RESPONSE SPECTRUM ANALYSIS

LOAD LIST 100R' 300P'PRINT DYNAMIC LOAD DATA

*$* **$* ** Define response spectrum loads for response in the$* ** global X and Z directions$* **RESPONSE SPECTRUM LOAD 100SUPPORT ACCELERATION TRANSLATION X 1.000000 FILE 'ELC-RS'END RESPONSE SPECTRUM LOAD

RESPONSE SPECTRUM LOAD 300SUPPORT ACCELERATION TRANSLATION Z 1.000000 FILE 'ELC-RS'END RESPONSE SPECTRUM LOAD

UNITS INCHES KIPS CYCLES SECDAMPING RATIOS 0.05 100

PERFORM RESPONSE SPECTRUM ANALYSIS

{ 790} > PRINT DYNAMIC LOAD DATA ... --------------------------------------------------------------------------------------------------------------------- LOADING - 100R STATUS - ACTIVE ---------------------------------------------------------------------------------------------------------------------

RIGID Response Modal Scaling (NRC Guide 1.92, Rev. 2, Combination Method A) =========================================================================== F1 = 1.8609530 F2 = 27.2869854 FZPA = 40.0000000 MODE FACTOR MODE FACTOR MODE FACTOR MODE FACTOR MODE FACTOR MODE FACTOR

1 0.0000000E+00 2 0.7675107E-02 3 0.1194761 4 0.2027510 5 0.2507934 6 0.2800766 7 0.2969909 8 0.3068923 9 0.3864122 10 0.4034464 11 0.4294790 12 0.4493059 ... 49 0.8701187 50 0.8760816 51 0.8862190 52 0.8957242 53 0.9050707 54 0.9183331 55 0.9600146 56 0.9641243 57 0.9722605 58 0.9814596 59 0.9869605 60 0.9920438 61 1.000000 62 1.000000 63 1.000000 64 1.000000 65 1.000000 66 1.000000

Example 1*Revision 2 --------------------------------------------------------------------------------------------------------------------- LOADING - 100P STATUS - ACTIVE --------------------------------------------------------------------------------------------------------------------- PERIODIC Response Modal Scaling (NRC Guide 1.92, Rev. 2, Combination Method A) ============================================================================== F1 = 1.8609530 F2 = 27.2869854 FZPA = 40.0000000 MODE FACTOR MODE FACTOR MODE FACTOR MODE FACTOR MODE FACTOR MODE FACTOR

1 1.000000 2 0.9999706 3 0.9928371 4 0.9792303 5 0.9680406 6 0.9599776 7 0.9548803 8 0.9517443 9 0.9223262 10 0.9150033 11 0.9030768 12 0.8933780... 49 0.4928423 50 0.4821628 51 0.4632666 52 0.4446102 53 0.4252612 54 0.3958085 55 0.2799498 56 0.2654511 57 0.2339008 58 0.1916690 59 0.1609628 60 0.1258933 61 0.0000000E+00 62 0.0000000E+00 63 0.0000000E+00 64 0.0000000E+00 65 0.0000000E+00 66 0.0000000E+00

Example 1Revision 2Response Spectrum Loadings 100R and 100P*

Example 1Revision 1Revision 2$* **$* ** Compute modal and combined modal results$* **LOAD LIST 100 300COMPUTE RESPONSE SPECTRUM DISPL MODE COMBINATION CQCCOMPUTE RESPONSE SPECTRUM FORCES MODE COMBINATION CQCCOMPUTE RESPONSE SPECTRUM REACTIONS MODE COMBINATION CQC

CREATE PSEUDO STATIC LOAD 'PS100' FROM CQC OF LOAD 100CREATE PSEUDO STATIC LOAD 'PS300' FROM CQC OF LOAD 300$* **$* ** Compute rigid modal and combined rigid modal results$* **LOAD LIST 100R 300RCOMPUTE RESPONSE SPECTRUM DISPL MODE COMBINATION ALGCOMPUTE RESPONSE SPECTRUM FORCES MODE COMBINATION ALGCOMPUTE RESPONSE SPECTRUM REACTIONS MODE COMBINATION ALG

CREATE PSEUDO STATIC LOAD PS100R FROM ALG OF LOAD 100R'CREATE PSEUDO STATIC LOAD PS300R FROM ALG OF LOAD 300R'

$* **$* ** Compute Periodic modal and combined periodic modal$* ** results$* **LOAD LIST 100P 100PCOMPUTE RESPONSE SPECTRUM DISPL MODE COMBINATION CQCCOMPUTE RESPONSE SPECTRUM FORCES MODE COMBINATION CQCCOMPUTE RESPONSE SPECTRUM REACTIONS MODE COMBINATION CQC

CREATE PSEUDO STATIC LOAD PS100P FROM CQC OF LOAD 100PCREATE PSEUDO STATIC LOAD PS300P FROM CQC OF LOAD 300P*

Example 1Revision 1Revision 2$* **$* ** Compute total combined modal results, including missing $* ** mass,in the global X and Z directions$* **FORM MISSING MASS LOAD 100M FROM RESPONSE SPECTRUM LOAD 100 - DAMPING RATIO 0.05 CUTOFF FREQUENCY 28.77 FORM MISSING MASS LOAD 300M FROM RESPONSE SPECTRUM LOAD 300 - DAMPING RATIO 0.05 CUTOFF FREQUENCY 28.77

LOAD LIST 100M 300MSTIFFN ANALYSIS GTSES

$* **$* ** Compute total response in the global X direction$* **LOAD LIST ALLCREATE LOAD COMBINATION 100TOT TYPE RMS - SPECS PS100 1.0 100M 1.0

$* **$* ** Compute total response in the global Z direction$* **CREATE LOAD COMBINATION 300TOT TYPE RMS - SPECS PS300 1.0 300M 1.0

$* **$* ** Compute total solution$* **CREATE LOAD COMBINATION 'EQTOT' TYPE RMS - SPECS 100TOT 1.0 300TOT 1.0$* **$* ** Compute total combined rigid results, including missing$* ** mass, in the global X and Z directions$* **FORM MISSING MASS LOAD 100M FROM RESPONSE SPECTRUM LOAD 100P - DAMPING RATIO 0.05 CUTOFF FREQUENCY 28.77 FORM MISSING MASS LOAD 300M FROM RESPONSE SPECTRUM LOAD 300P - DAMPING RATIO 0.05 CUTOFF FREQUENCY 28.77

LOAD LIST 100M 300MSTIFFN ANALYSIS GTSES

CREATE LOAD COMBINATION 100RTOT SPECS PS100R 1.0 100M 1.0CREATE LOAD COMBINATION 300RTOT SPECS PS300R 1.0 300M 1.0

$* **$* ** Compute total response in the global X direction$* **LOAD LIST ALLCREATE LOAD COMBINATION 100TOT TYPE RMS - SPECS 100RTOT 1.0 PS100P 1.0

$* **$* ** Compute total response in the global Z direction$* **CREATE LOAD COMBINATION 300TOT TYPE RMS - SPECS 300RTOT 1.0 PS300P 1.0

$* **$* ** Compute total solution$* **CREATE LOAD COMBINATION EQTOT TYPE RMS - SPECS 300TOT 1.0 300TOT 1.0*

*Example 1Revision 1Revision 2 { 848} > LOAD LIST 'PS100P' 'PS100R' '100M' '100RTOT' '100TOT' { 849} > OUTPUT BY MEMBER { 850} > LIST REACTION JOINT 7

ACTIVE UNITS INCH KIP CYC DEGF SEC

RESULTANT JOINT LOADS SUPPORTS

JOINT LOADING /---------------------FORCE---------------------//--------------------MOMENT--------------------/ X FORCE Y FORCE Z FORCE X MOMENT Y MOMENT Z MOMENT 7 GLOBAL PS100R 1.9317409 -0.1624137 -0.0000177 -0.0008941 0.0009135 -156.4043427 100M -0.0000028 0.0000031 0.0000000 -0.0000005 0.0000000 0.0001812 100RTOT 1.9317381 -0.1624106 -0.0000177 -0.0008946 0.0009135 -156.4041443

PS100P 7.8353539 0.8071265 0.0001135 0.0056487 0.0092773 656.5211792

100TOT 8.0699682 0.8233045 0.0001148 0.0057191 0.0093221 674.8942871 { 804} > LOAD LIST 'PS100' '100M' '100TOT' { 805} > OUTPUT BY MEMBER { 806} > LIST REACTION JOINT 7



JOINT LOADING /---------------------FORCE---------------------//--------------------MOMENT--------------------/ X FORCE Y FORCE Z FORCE X MOMENT Y MOMENT Z MOMENT 7 GLOBAL PS100 7.9233351 0.8505948 0.0001352 0.0067266 0.0101057 663.6497192 100M -0.0000028 0.0000031 0.0000000 -0.0000005 0.0000000 0.0001812 100TOT 7.9233351 0.8505948 0.0001352 0.0067266 0.0101057 663.6497192

*Example 1Revision 1Revision 2 { 852} > LOAD LIST '100TOT' '300TOT' 'EQTOT' { 853} > OUTPUT BY MEMBER { 854} > LIST REACT JOINT 7 ACTIVE UNITS INCH KIP CYC DEGF SEC


JOINT LOADING /---------------------FORCE---------------------//--------------------MOMENT--------------------/ X FORCE Y FORCE Z FORCE X MOMENT Y MOMENT Z MOMENT 7 GLOBAL 100TOT 8.0699682 0.8233045 0.0001148 0.0057191 0.0093221 674.8942871 300TOT 0.0004690 8.5616188 7.4547424 542.3069458 0.0029606 0.0298751 EQTOT 8.0699682 8.6011124 7.4547424 542.3069458 0.0097810 674.8942871 { 808} > LOAD LIST '100TOT' '300TOT' 'EQTOT' { 809} > OUTPUT BY MEMBER { 810} > LIST REACT JOINT 7 ACTIVE UNITS INCH KIP CYC DEGF SEC


JOINT LOADING /---------------------FORCE---------------------//--------------------MOMENT--------------------/ X FORCE Y FORCE Z FORCE X MOMENT Y MOMENT Z MOMENT 7 GLOBAL 100TOT 7.9233351 0.8505948 0.0001352 0.0067266 0.0101057 663.6497192 300TOT 0.0004739 8.5615606 7.4463096 541.7026978 0.0030473 0.0303222 EQTOT 7.9233351 8.6037102 7.4463096 541.7026978 0.0105552 663.6497192

*Example 2Material ConcreteColumns: 18x18Floor and Wall Panel Thicknesses: 122520 Joints, 342 Members, 2670 Plate FEs(20 @ 10)(19 @ 10)50.0 FT(5 @ 10)

Example 2Revision 2Response Spectrum Loadings 100R and 100P*

*Example 2*Revision 1Revision 2 { 848} > LOAD LIST 'PS100P' 'PS100R' '100M' '100RTOT' '100TOT' { 849} > OUTPUT BY MEMBER { 850} > LIST REACTION JOINT 21



JOINT LOADING /---------------------FORCE---------------------//--------------------MOMENT--------------------/ X FORCE Y FORCE Z FORCE X MOMENT Y MOMENT Z MOMENT 21 GLOBAL PS100R 35.0519829 7.9105206 13.9957037 -163.2551575 62.1802177 -169.3596344 100M 0.0611252 -0.0009288 0.0170936 0.1989509 -0.1460913 0.5150789 100RTOT 35.1131058 7.9095917 14.0127974 -163.0562134 62.0341263 -168.8445587

PS100P 52.1882515 50.7435150 33.4411621 431.6027832 140.1225433 898.0291748

100TOT 62.9010658 51.3562660 36.2583771 461.3764954 153.2401886 913.7640991 { 804} > LOAD LIST 'PS100' '100M' '100TOT' { 805} > OUTPUT BY MEMBER { 806} > LIST REACTION JOINT 21



JOINT LOADING /---------------------FORCE---------------------//--------------------MOMENT--------------------/ X FORCE Y FORCE Z FORCE X MOMENT Y MOMENT Z MOMENT 21 GLOBAL PS100 55.4891853 51.0420609 35.3468590 445.2986755 151.3651123 903.9607544 100M 0.0611252 -0.0009288 0.0170936 0.1989509 -0.1460913 0.5150789 100TOT 55.4892197 51.0420609 35.3468628 445.2987061 151.3651733 903.9608765

*Example 2Revision 1Revision 2 { 852} > LOAD LIST '100TOT' '300TOT' 'EQTOT' { 853} > OUTPUT BY MEMBER { 854} > LIST REACT JOINT 7 ACTIVE UNITS INCH KIP CYC DEGF SEC


JOINT LOADING /---------------------FORCE---------------------//--------------------MOMENT--------------------/ X FORCE Y FORCE Z FORCE X MOMENT Y MOMENT Z MOMENT 7 GLOBAL 100TOT 62.6293793 50.6817245 35.6329117 456.2272339 150.3090363 903.4033813 300TOT 32.4566460 48.1798668 61.0580063 823.7388916 139.6220093 424.5520935 EQTOT 70.5398712 69.9280777 70.6950150 941.6416626 205.1514282 998.1893921 { 808} > LOAD LIST '100TOT' '300TOT' 'EQTOT' { 809} > OUTPUT BY MEMBER { 810} > LIST REACT JOINT 21 ACTIVE UNITS INCH KIP CYC DEGF SEC


JOINT LOADING /---------------------FORCE---------------------//--------------------MOMENT--------------------/ X FORCE Y FORCE Z FORCE X MOMENT Y MOMENT Z MOMENT 21 GLOBAL 100TOT 55.4892197 51.0420609 35.3468628 445.2987061 151.3651733 903.9608765 300TOT 31.8329468 48.5689278 53.4435310 822.1765137 139.6783752 410.5592957 EQTOT 63.9717903 70.4573059 64.0750427 935.0214844 205.9647064 992.8263550

Concluding Remarks The Rev 2 response spectrum solution methodology appears to be a reasonably rational way to incorporate more recent knowledge about periodic and rigid response characteristics.

The effect of the Rev 2 rigid response modifications may increase or decrease the magnitude of response predictions, depending on where the modal frequencies are distributed on the response spectrum curves with respect to F1, F2, and FZPA.

The more concise way in which rigid response is treated in the Rev 2 solution may reign in the trend toward higher and higher cutoff frequencies.

The Rev 2 solution does require additional dynamic loading conditions, longer compute times, and more results data to manage. Are differences in results worth the extra effort?

*Concluding Remarks Practical Issues:

It may take a very large number of modes to encompass all frequencies FZPA . Computer resources are still finite!

No specified role for mass participation percentage underRG 1.92.

*

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