GTStrudl Version 30

1
GTStrudl Version 30 Response Spectrum Analysis
Enhancements Related To NRC Regulatory Guide
1.92, Revision 2 COMBINING MODAL RESPONSES AND
SPATIAL COMPONENTS in SEISMIC RESPONSE ANALYSIS
Michael H. Swanger, Ph.D. Georgia Tech CASE
Center GTSUG 2008 June 23-26, 2008 Las Vegas, NV
2
Topics

• Background
• NRC Reg Guide 1.92, Rev 1 Positions
• Response Spectrum Characteristics
• Response Spectrum Solution Strategy
• NRC Reg Guide 1.92, Rev 2 Positions
• Response Spectrum Characteristics
• Response spectrum Solution Strategy
• GTStrudl Enhancements, Version 30
• The RESPONSE SPECTRUM LOAD/
• MODE FACTORS Command
• The ALGEBRAIC Mode Combination
• Total Response
• Example
• NRC Reg Guide 1.92 Rev 1 vs Rev 2

3

• Background

3
4

• Background

5

• Background
• NRC Reg Guide 1.92, Rev 1 Positions

Response Spectrum Characteristics
All modes are assumed to be out-of-phase with the
ground acceleration and out-of-phase with each
other
Acceleration
All modes having frequencies some arbitrary
cutoff frequency are deemed significant for
inclusion in the response spectrum analysis
Frequency
Note 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!
6

• Background
• NRC Reg Guide 1.92, Rev 1 Positions

Response 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

7

• Background
• NRC Reg Guide 1.92, Rev 1 Positions

Response 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
8

• Background
• NRC Reg Guide 1.92, Rev 1 Positions

Response Spectrum Solution Strategy

• If frequencies are closely spaced

• NRC Grouping Method
• NRC Ten Percent Method
• NRC Double Sum Method

td duration of earthquake
9

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response 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
10

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response Spectrum Characteristics

• fi F1

Maximum response from periodic or transient
response in the modal frequency fi. Maximum
modal (oscillator) responses are out-of-phase
with one another.
10
11

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response Spectrum Characteristics
Mid Frequency Transition from Out-of-Phase
to In-Phase Response
Low Frequency Out-of-Phase Response
High Frequency In-Phase Rigid Static Response
Frequency

• fi F2

Maximum response from steady state response. The
maximum modal responses are in phase with one
another.
11
12

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response Spectrum Characteristics
Mid Frequency Transition from Out-of-Phase
to In-Phase Response
Low Frequency Out-of-Phase Response
High Frequency In-Phase Rigid Static Response
Frequency

• F1 lt fi lt F2

Response is part periodic and part rigid.
Maximum modal responses transition from
out-of-phase to in phase.
12
13

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response 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

14

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response 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

15

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response 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
16

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response Spectrum Solution Strategy

• Computation of rigid response factor aki The
  Gupta Method

Mid Frequency Transition from Out-of-Phase
to In-Phase Response
Low Frequency Out-of-Phase Response
High Frequency In-Phase Rigid Static Response
Frequency
17

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response Spectrum Solution Strategy

• Periodic responses are combined using a
  double sum rule

• eij computed according to the following methods
• SRSS Method
• NRC Double Sum Method (Rosenbleuth correlation
  coefficient)
• CQC method (Der Kiureghians correlation
  coefficient)

17
18

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response Spectrum Solution Strategy

• Computation of the Residual Rigid Response for
  all fi 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
19

• Background
• NRC Reg Guide 1.92, Rev 2 Positions

Response 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
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20

• GTStrudl Enhancements, Version 30

RESPONSE SPECTRUM LOAD/MODE FACTORS Command

• Syntax

Purpose To compute a and (1 a2)1/2 for each
active mode for the defined response spectrum
load
20
21

• GTStrudl Enhancements, Version 30

RESPONSE SPECTRUM LOAD/MODE FACTORS Command

• Example

UNITS CYCLES SECONDS RESPONSE SPECTRUM LOAD
100R SUPPORT ACCELERATION TRANSLATION X
1.000000 FILE ELC-RS MODE FACTORS COMPUTE
RIGID RESPONSE FZPA 40.0 END RESPONSE SPECTRUM
LOAD RESPONSE SPECTRUM LOAD 100P SUPPORT
ACCELERATION TRANSLATION X 1.000000 FILE
ELC-RS MODE FACTORS COMPUTE PERIODIC
RESPONSE FZPA 40.0 END RESPONSE SPECTRUM LOAD
Note FZPA is specified (FZPA 40.0)
therefore F1 Samax/(2pSvmax) F2 (F1
2FZPA)/3
22

• GTStrudl Enhancements, Version 30

The ALGEBRAIC Mode Combination
23

• GTStrudl Enhancements, Version 30

The ALGEBRAIC Mode Combination

• Example

LOAD LIST 100R Rigid RS
Components COMPUTE RESPONSE SPECTRUM
DISPLACEMENTS MODE COMBINATION ALGEBRAIC COMPUTE
RESPONSE SPECTRUM FORCES MODE COMBINATION
ALBEGRAIC CREATE PSEUDO STATIC LOAD PS100R FROM
ALGEBRAIC OF LOAD 100R . . . LOAD LIST
100P Periodic RS Components COMPUTE
RESPONSE SPECTRUM DISPLACEMENTS MODE COMBINATION
CQC COMPUTE RESPONSE SPECTRUM FORCES MODE
COMBINATION CQC CREATE PSEUDO STATIC LOAD
PS100P FROM CQC OF LOAD 100P
24

• GTStrudl Enhancements, Version 30

Total Rigid, Directional, and Solution Response

• Example

Total Rigid Response UNITS
CYCLES SECONDS FORM 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
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• Example 1

(6 _at_ 12)
(5 _at_ 10)
(4 _at_ 10)
Columns W14X53 Beams (Global X)
W18X35 Beams (Global Z) W18X50 210 Joints,
474 Members
Additional Mass 1 kip, all joints, Global X
and Z Seismic Loading El Centro RS, Global X
and Z
26

• Example 1

El Centro Response Spectrum
UNITS FEET CYCLES SECONDS CREATE 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
20.00000 END OF CREATE RESPONSE SPECTRUM
FZPA
F1 1.9 HZ
F2 27.3 HZ
26
27

• Example 1

Revision 1
Revision 2
UNITS INCHES KIPS DEAD LOAD 'DLX' DIR X ALL
MEMBERS DEAD LOAD 'DLZ' DIR Z ALL MEMBERS INERTIA
OF JOINTS FROM LOAD 'DLX' SAME DOFS INERTIA OF
JOINTS FROM LOAD 'DLZ' SAME DOFS INERTIA OF
JOINTS WEIGHT EXISTING TRANSL X 1.0 Z
1.0 UNITS CYCLES SECONDS EIGENVALUE PARAMETERS
SOLVE USING GTSEL FREQUENCY SPECS 0.0 TO 40.0
PRINT MAX END DYNAMIC ANALYSIS EIGENVALUE
UNITS INCHES KIPS DEAD LOAD 'DLX' DIR X ALL
MEMBERS DEAD LOAD 'DLZ' DIR Z ALL MEMBERS INERTIA
OF JOINTS FROM LOAD 'DLX' SAME DOFS INERTIA OF
JOINTS FROM LOAD 'DLZ' SAME DOFS INERTIA OF
JOINTS WEIGHT EXISTING TRANSL X 1.0 Z
1.0 UNITS CYCLES SECONDS EIGENVALUE PARAMETERS
SOLVE USING GTSEL FREQUENCY SPECS 0.0 TO 40.0
PRINT MAX END DYNAMIC ANALYSIS EIGENVALUE
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• Example 1

Revision 1
Revision 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 40.0 END RESPONSE SPECTRUM
LOAD RESPONSE SPECTRUM LOAD 300R' SUPPORT
ACCELERATION TRANSLATION Z 1.000000 FILE
'ELC-RS' MODE FACTORS COMPUTE RIGID RESPONSE
FZPA 40.0 END 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 40.0 END RESPONSE SPECTRUM
LOAD RESPONSE SPECTRUM LOAD 300P' SUPPORT
ACCELERATION TRANSLATION Z 1.000000 FILE
'ELC-RS' MODE FACTORS COMPUTE PERIODIC RESPONSE
FZPA 40.0 END RESPONSE SPECTRUM LOAD UNITS
INCHES KIPS CYCLES SEC DAMPING 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
100 SUPPORT ACCELERATION TRANSLATION X
1.000000 FILE 'ELC-RS' END RESPONSE SPECTRUM
LOAD RESPONSE SPECTRUM LOAD
300 SUPPORT ACCELERATION TRANSLATION Z
1.000000 FILE 'ELC-RS' END RESPONSE SPECTRUM
LOAD UNITS INCHES KIPS CYCLES
SEC DAMPING RATIOS 0.05 100 PERFORM RESPONSE
SPECTRUM ANALYSIS
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• Example 1

Revision 2
790 gt 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 0.0000000E00 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

-------------------------------------------------
--------------------------------------------------
------------------ 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
0.0000000E00 62 0.0000000E00 63
0.0000000E00 64 0.0000000E00 65
0.0000000E00 66 0.0000000E00
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30

• Example 1

Revision 2
Response Spectrum Loadings 100R and 100P
30
31

• Example 1

Revision 1
Revision 2
Compute modal and combined modal
results LOAD LIST 100 300 COMPUTE RESPONSE
SPECTRUM DISPL MODE COMBINATION CQC COMPUTE
RESPONSE SPECTRUM FORCES MODE COMBINATION
CQC COMPUTE RESPONSE SPECTRUM REACTIONS MODE
COMBINATION CQC CREATE PSEUDO STATIC LOAD
'PS100' FROM CQC OF LOAD 100 CREATE PSEUDO
STATIC LOAD 'PS300' FROM CQC OF LOAD 300
Compute rigid modal and combined
rigid modal results LOAD LIST 100R
300R COMPUTE RESPONSE SPECTRUM DISPL MODE
COMBINATION ALG COMPUTE RESPONSE SPECTRUM FORCES
MODE COMBINATION ALG COMPUTE 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 100P COMPUTE
RESPONSE SPECTRUM DISPL MODE COMBINATION
CQC COMPUTE RESPONSE SPECTRUM FORCES MODE
COMBINATION CQC COMPUTE RESPONSE SPECTRUM
REACTIONS MODE COMBINATION CQC CREATE PSEUDO
STATIC LOAD PS100P FROM CQC OF LOAD
100P CREATE PSEUDO STATIC LOAD PS300P FROM
CQC OF LOAD 300P
31
32

• Example 1

Revision 1
Revision 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 300M STIFFN ANALYSIS
GTSES Compute total response in
the global X direction LOAD LIST ALL CREATE
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 300M STIFFN ANALYSIS
GTSES CREATE LOAD COMBINATION 100RTOT SPECS
PS100R 1.0 100M 1.0 CREATE LOAD COMBINATION
300RTOT SPECS PS300R 1.0 300M 1.0
Compute total response in the global X
direction LOAD LIST ALL CREATE 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
33

• Example 1

Revision 1
804 gt LOAD LIST 'PS100' '100M' '100TOT'
805 gt OUTPUT BY MEMBER 806 gt 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 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
Revision 2
848 gt LOAD LIST 'PS100P' 'PS100R' '100M'
'100RTOT' '100TOT' 849 gt OUTPUT BY MEMBER
850 gt 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
34

• Example 1

Revision 1
808 gt LOAD LIST '100TOT' '300TOT' 'EQTOT'
809 gt OUTPUT BY MEMBER 810 gt LIST REACT
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
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
Revision 2
852 gt LOAD LIST '100TOT' '300TOT' 'EQTOT'
853 gt OUTPUT BY MEMBER 854 gt LIST REACT
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
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
35

• Example 2

50.0 FT (5 _at_ 10)
(20 _at_ 10)
(19 _at_ 10)
Material Concrete Columns 18x18 Floor and
Wall Panel Thicknesses 12 2520 Joints, 342
Members, 2670 Plate FEs
36

• Example 2

Revision 2
Response Spectrum Loadings 100R and 100P
36
37

• Example 2

Revision 1
804 gt LOAD LIST 'PS100' '100M' '100TOT'
805 gt OUTPUT BY MEMBER 806 gt LIST REACTION
JOINT 21 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 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
Revision 2
848 gt LOAD LIST 'PS100P' 'PS100R' '100M'
'100RTOT' '100TOT' 849 gt OUTPUT BY MEMBER
850 gt LIST REACTION JOINT 21 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 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
37
37
38

• Example 2

Revision 1
808 gt LOAD LIST '100TOT' '300TOT' 'EQTOT'
809 gt OUTPUT BY MEMBER 810 gt LIST REACT
JOINT 21 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 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
Revision 2
852 gt LOAD LIST '100TOT' '300TOT' 'EQTOT'
853 gt OUTPUT BY MEMBER 854 gt LIST REACT
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
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
38
39
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?

40
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 under
• RG 1.92.