Part 6 - Spectral Fatigue

Spectral Fatigue - 1

Part 6 - Spectral Fatigue Preparation

1) Under “Training Project”, create “Spectral Fatigue” subdirectory 2) Under “Spectral Fatigue”, Create “Foundation SE”, “Modes” and “Fatigue”

subdirectories. 3) Copy SACINP.STA model file, SEAINP.STA Seastate file and PSIINP.DAT soil data

from “\Spectral Earthquake\Static SE” directory to “Foundation SE” directory. 4) Copy SEAINP.DYN from “\Spectral Earthquake\Modes” directory to “Modes” directory

Creating foundation superelement under “Foundation SE” directory,

1) Modifying Model file SACINP.STA for creating foundation superelement suitable for wave response analysis

Live weight factor in weight combination MASS shall be modified from 0.75 to 1.0.

2) Modifying Seastate file SEAINP.STA for create foundation superelement suitable for

wave response analysis

Delete load conditions GRVX and GRVY; Add two new load conditions named as X000 and Y090, wave loads will be generated for 1.5 m wave height at 4.42 sec wave period for both 000 and 090 directions respectively. Stream function will be used for calculating wave force in 18 steps; maximum base shear will be selected for critical position. Weight selection lines INCWGT used to select weight groups ANOD and WKWY for possible wave forces. Delete load combination EQKS. Combine load combinations SUPX and SUPY with X000 and Y090 correspondingly. Modify LCSEL line to only include SUPX and SUPY load combinations.

Part of Seastate input file defined shall looks like following: ------------------------------------------------------------------------------------------------------------- LDOPT NF+Z 1.025 7.85 -79.50 79.50 MN NPNP K LCSEL SUPX SUPY … LOAD LOADCNDEAD INCWGT ANODWKWY DEAD DEAD -Z M LOADCNMASS INCWGT MASS ACCEL 1.0 N CEN1 LOADCNX000 INCWGT ANODWKWY


WAVE WAVE STRE 1.5 4.42 0.00 D 0.00 20.0 18MS 0 LOADCNY090 INCWGT ANODWKWY WAVE WAVE STRE 1.5 4.42 90.00 D 0.00 20.0 18MS 0 LCOMB LCOMB SUPX DEAD 1.0MASS 1.0X000 1.0 LCOMB SUPY DEAD 1.0MASS 1.0Y090 1.0 END

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3) Delete Title line of PSIINP.DAT, otherwise it will has problem in following fatigue analysis

4) Creating run file to generate foundation superelement using SUPX and SUPY.

Check “Edit Environmental Loading Options” to include the separate Seastate input; In “Edit Foundation Options” > “Foundation” part, select “Override - Create Pilehead SE” for “Foundation Superelement Option” and input SUPX and SUPY to 1st X and 1st Y load cases respectively, “Max load and deflection” will be used for pile head load/deflection option. No “Element Check” and “Postvue” database needed for this analysis. Run analysis.


Seastate basic load case summary report for spectral fatigue: ----------------------------------------------------------------------------------------------------------------------------------- ****** SEASTATE BASIC LOAD CASE SUMMARY ****** RELATIVE TO MUDLINE ELEVATION LOAD LOAD FX FY FZ MX MY MZ DEAD LOAD BUOYANCY CASE LABEL (KN) (KN) (KN) (KN-M) (KN-M) (KN-M) (KN) (KN) 1 DEAD 0.000 0.000 -5719.634 -31.034 10787.661 0.000 8604.555 2884.945 2 MASS 0.000 0.000 -5493.466 -558.791 8283.856 0.000 0.000 0.000 3 X000 5.448 -0.049 0.997 4.123 447.308 7.858 0.000 0.000 4 Y090 -0.541 25.159 1.372 -1868.693 -43.821 -21.032 0.000 0.000 -------------------------------------------------------------------------------------------------------------------------------------

Seastate combined load case summary report for spectral fatigue: ----------------------------------------------------------------------------------------------------------------------------------- ***** SEASTATE COMBINED LOAD CASE SUMMARY ***** RELATIVE TO MUDLINE ELEVATION LOAD LOAD FX FY FZ MX MY MZ CASE LABEL (KN) (KN) (KN) (KN-M) (KN-M) (KN-M) 5 SUPX 5.448 -0.049 -11212.104 -585.702 19518.826 7.858 6 SUPY -0.541 25.159 -11211.729 -2458.519 19027.697 -21.032 -------------------------------------------------------------------------------------------------------------------------------------

Pile head superelement created for joint 101P for spectral fatigue: ----------------------------------------------------------------------------------------------------------------------------------- *** PILEHEAD STIFFNESS FOR JOINT 101P *** UNITS - (KN,M) FOR SUPERELEMENT NO. 1 RX RY RZ DX DY DZ RX RY RZ DX DY DZ RX 0.398342E+06 0.455822E+01 -0.455822E+00 0.147119E+00 0.546808E+05 -0.546808E+04 RY 0.455822E+01 0.394482E+06 -0.389482E+05 -0.546797E+05 -0.145662E+00 0.145662E-01 RZ -0.455822E+00 -0.389482E+05 0.889482E+04 0.546797E+04 0.145662E-01 -0.145662E-02 DX 0.147119E+00 -0.546797E+05 0.546797E+04 0.132517E+05 -0.151665E+00 0.151665E-01 DY 0.546808E+05 -0.145662E+00 0.145662E-01 -0.151665E+00 0.245338E+05 0.112833E+06 DZ -0.546808E+04 0.145662E-01 -0.145662E-02 0.151665E-01 0.112833E+06 0.114158E+07 -------------------------------------------------------------------------------------------------------------------------------------


Mode extraction under “Modes” directory,

Create Dynapac run file “Extract Mode Shapes”

Check “Edit Environmental Loading Options” to include the separate Seastate input; Under “Edit Solve Options”, select “Yes” to “Include Superelement File”; Under “Edit Modal Extraction Options”, input 50 to “Number of Modes” and select “Create added mass of beams”. Create “Postvue” database. Browse in “Foundation SE” directory for SACINP.STA when prompted for “SACS Model File” and browse in “Foundation SE” directory for DYNSEF.STA file for Superelement file. . Run Analysis.


Dynpac weight summary report for spectral fatigue: ----------------------------------------------------------------------------------------------------------------------------------- ************* WEIGHT AND CENTER OF GRAVITY SUMMARY ************* ************ ITEM DESCRIPTION ************ ************** WEIGHT ************** ******** CENTER OF GRAVITY ******** X Y Z X Y Z KN KN KN M M M PLATE ELEMENTS 387.938 387.938 387.938 1.429 0.000 19.699 MEMBER ELEMENTS 7866.831 7866.831 7866.831 2.227 0.042 -36.161 MEMBER ELEMENT NORMAL ADDED MASS 4591.960 4542.602 1496.886 2.364 0.037 -58.283 FLOODED MEMBER ELEMENT ENTRAPPED FLUID 2541.104 2541.104 2541.104 2.199 0.000 -39.503 USER DEFINED WEIGHTS IN DYNPAC 5949.531 5949.531 5949.531 1.558 0.073 17.440 ************ TOTAL ************ 21337.365 21288.007 18242.291 2.052 0.044 -19.773 -------------------------------------------------------------------------------------------------------------------------------------

Dynpac first 10 modal periods and frequencies report for spectral fatigue: ----------------------------------------------------------------------------------------------------------------------------------- SACS IV-FREQUENCIES AND GENERALIZED MASS MODE FREQ.(CPS) GEN. MASS EIGENVALUE PERIOD(SECS) 1 0.299365 7.5745887E+02 2.8264298E-01 3.3404039 2 0.324509 4.4501464E+02 2.4053940E-01 3.0815768 3 0.479421 4.1442723E+02 1.1020612E-01 2.0858484 4 0.724061 1.3751426E+03 4.8315864E-02 1.3810988 5 0.750267 1.2431153E+03 4.4999557E-02 1.3328584 6 0.952067 2.0130674E+03 2.7945043E-02 1.0503457 7 1.499704 7.6823626E+02 1.1262357E-02 0.6667984 8 1.524094 7.5880577E+02 1.0904775E-02 0.6561275 9 1.912919 2.0876937E+02 6.9222470E-03 0.5227613 10 1.957074 1.3436331E+02 6.6134160E-03 0.5109669 -------------------------------------------------------------------------------------------------------------------------------------


Wave Response analysis under “Fatigue” directory,

1) Create Seastate input file SEAINP.000, SEAINP.045 and SEAINP.090 for Transfer function generation

Copy SEAINP.DYN Seastate file from “Modes” directory and rename to SEAINP.000. Input DYN analysis option in col.56-58 for generating loading and hydrodynamic modeling for dynamics. Input title line as “000 DIRECTION TRANSFER FUNCTION”. Four load cases 1 through 4 will be added, each load case contain one line of GNTRF transfer function generation line. For fist load case in 000 direction: 6 waves in 18 steps will be generated using wave steepness 0.05; beginning wave period 10 seconds and period step size 1.00 seconds; transfer function loading will be generated for each wave position and AIRY wave theory will be selected. Base shear and overturning moment will be plotted

For second load case in 000 direction, 6 waves with starting period = 4.75 secs and period step size = 0.25 secs. For third load case in 000 direction, 11 waves with starting period = 3.40 secs and period step size = 0.10 secs. For fourth load case in 000 direction, 2 waves with starting period = 2.25 secs and period step size = 0.25 secs. Copy SEAINP.000 Seastate file to SEAINP.045 and SEAINP.090. Modify GNTRF directions to 45.00 for SEAINP.045 and to 90.00 for SEAINP.090.

Part of Seastate input file defined for 000 direction shall looks like following: ------------------------------------------------------------------------------------------------------------- LDOPT NF+Z 1.025 7.85 -79.50 79.50 MN DYN NPNP K 000 DIRECTION TRANSFER FUNCTION FILE S … LOAD LOADCN 1 GNTRF AL 6 0.05 10.00 1.00 0.00 18AIRYPF LOADCN 2 GNTRF AL 6 0.05 4.75 0.25 0.00 18AIRYPF LOADCN 3 GNTRF AL 11 0.05 3.40 0.10 0.00 18AIRYPF LOADCN 4 GNTRF AL 2 0.05 2.25 0.25 0.00 18AIRYPF END

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2) Create wave response input file WVRINP.PLT for transfer function plot

For Wave Response Options, select “ALL” to Load case selection, choose “Generate Plots”, maximum allowable iterations = -1. Use Transfer function plot line PLTTF to request Overturning moment and Base shear plot for both period and frequency. 1 to 25 load case selected for transfer function load case TFLCAS. Damping ratio for spectral fatigue use 2% for all modes.

Wave response plot input file defined shall looks like following: ------------------------------------------------------------------------------------------------------------- WROPT MNPSL ALL -1 PLTTF OM BS PFS TFLCAS 1 25 DAMP 2.0 END

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3) Create wave response run file and creating transfer function plot for 000 direction Under “Dynamics”, select “Wave Transfer/Response function Generation”; Check “Edit Environmental Loading Options” to include the separate Seastate input, select SEAINP.000 as input; Under “Edit Dynamic Wave Options”, select “Yes” to “Use Wave Response Input File”; Browse to “Foundation SE” directory for model data file SACINP.STA, and browse to “Modes” directory for mode and mass file. Run the analysis and study the generated plots.

4) Creating wave response input file WVRINP.EQS for equivalent loads generation

Copy WVRINP.PLT to WVRINP.EQS, in wave options line, select “ES – Equivalent Static Loads”.

Wave response input file for equivalent loads defined shall looks like following: ------------------------------------------------------------------------------------------------------------- WROPT MNPSL ALL ES -1 PLTTF OM BS PFS TFLCAS 1 25 DAMP 2.0


END

------------------------------------------------------------------------------------------------------------- 5) Creating and solving equivalent loads for 000 direction

Under “Dynamics”, select “Deterministic Wave Analysis”; Check “Edit Environmental Loading Options” to include the separate Seastate input, select SEAINP.000 as input; Under “Edit Dynamic Wave Options”, select “Yes” to “Use Wave Response Input File”; Check “Edit Solve Options”; Check “Edit Foundation Options”, select “Yes” to “Create Pile Solution File” option; Browse to “Foundation SE” for model data file SACINP.STA and soil data file PSIINP.DAT; Browse to “Modes” for mode and mass files; Run Analysis.

6) Use the same procedure as 5) and solving equivalent loads for 045 and 090 directions. 7) Create fatigue input file FTGINP.FTG for spectral fatigue analysis

For fatigue options, Number of Additional Postfiles = 2 Design life = 20 yrs with Life safety factor = 2.0 Fatigue Time Period = 1.0 yrs

Check “Skip Non-Tubular Elements”, “Use Load Case Dependent SCF’s”, “Prescribe Max SCF” and “Prescribe MIN SCF” Choose API X prime curve for S-N Curve and Efthymiou method EFT for SCF calculation

For fatigue option 2 line, check “Member Summ. Rep. (Life Order)” and “SCF Validity Range Check”. Using joint override lines JNTOVR to define that joints 401L, 402L, 403L and 404L will be checked using API X curve rather than X prime curve. Using group selection line GRPSEL to remove member groups PL1, PL2, PL3, PL4 and W.B from fatigue calculation.


Using joint selection JSLC line to define only joints 201L, 202L, 203L, 204L, 301L, 302L, 303L, 304L, 401L, 402L, 403L and 404L will be included for fatigue damage evaluations. Using SCF limits line SCFLM to define max. SCF = 6.0 and min. SCF = 1.5. SCF Selection line SCFSEL can be used to define for X type joints, Marshall Method MSH will be used for SCF calculation. Add a RELIEF to force the program to evaluate the member hot spot stress at the surface of chord. SEAS line will be used to signal the program to read the Seastate input data file to determine the SACS load case to wave period and direction correlation. Input first fatigue load case corresponding to direction 000

Using Spectral Wave Fatigue Case FTLOAD to input Fraction of Design Life = 0.47 for 000 direction; input “SPC” into column 32-34 for spectral fatigue case. Using Scatter Diagram Header SCATD to select Pierson-Moskowitz Spectrum as type of wave spectrum. Using Scatter Diagram Wave height SCWAV to input sea states wave heights and using Scatter Diagram Freq. of Occurrence SCPER line to input Frequency of Occurrence per wave period. Percent occurrence for various wave heights and wave periods for 000 direction:

Dominant Period (SECS)

Significant Wave Height (M)

0.0 - 0.6 0.6 – 1.4 1.4 – 2.6

1.0 – 2.0 0.15 0.10 0.10

2.0 – 4.0 0.10 0.19 0.11

4.0 – 6.0 0.05 0.08 0.05

6.0 – 10.0 0.02 0.03 0.02

Input second fatigue load case corresponding to direction 045

Using Spectral Wave Fatigue Case FTLOAD to input Fraction of Design Life = 0.2 for 045 direction; input “SPC” into column 32-34 for spectral fatigue case.


Percent occurrence for various wave heights and wave periods for 045 direction:



0.0 - 0.6 0.6 – 1.4 1.4 – 2.6

1.0 – 2.0 0.10 0.13 0.08

2.0 – 4.0 0.15 0.13 0.10

4.0 – 6.0 0.08 0.08 0.07

6.0 – 10.0 0.03 0.02 0.03

Input third fatigue load case corresponding to direction 090

Using Spectral Wave Fatigue Case FTLOAD to input Fraction of Design Life = 0.33 for 090 direction; input “SPC” into column 32-34 for spectral fatigue case. Percent occurrence for various wave heights and wave periods for 090 direction:



0.0 - 0.6 0.6 – 1.4 1.4 – 2.6

1.0 – 2.0 0.13 0.10 0.08

2.0 – 4.0 0.13 0.15 0.10

4.0 – 6.0 0.06 0.09 0.08

6.0 – 10.0 0.03 0.03 0.02

Using Joint Extraction Head EXTRAC line to extract all joints with damage level greater than 0.5 for Interactive Fatigue review.

Fatigue input file defined shall looks like following: ------------------------------------------------------------------------------------------------------------- FATGIUE INPUT


FTOPT 2 20. 1.0 2. SMAPP MXMNSK LPEFT FTOPT2 PTVC JNTOVR 401L API JNTOVR 402L API JNTOVR 403L API JNTOVR 404L API GRPSEL RM PL1 PL2 PL3 PL4 W.B JSLC 201L202L203L204L301L302L303L304L401L402L403L404L SCFLM 6.0 1.5 SCFSEL MSH RELIEF SEAS FTLOAD 1 .47 1.0 SPC SCATD D 1.0 1.0 PM SCWAV 0.30 1.0 2.0 SCPER 1.5 .15 .1 .1 SCPER 3.0 .1 .19 .11 SCPER 5.0 .05 .08 .05 SCPER 8.0 .02 .03 .02 FTLOAD 2 .20 1.0 SPC SCATD D 1.0 1.0 PM SCWAV 0.30 1.0 2.0 SCPER 1.5 .10 .13 .08 SCPER 3.0 .15 .13 .10 SCPER 5.0 .08 .08 .07 SCPER 8.0 .03 .02 .03 FTLOAD 3 .33 1.0 SPC SCATD D 1.0 1.0 PM SCWAV 0.30 1.0 2.0 SCPER 1.5 .13 .10 .08 SCPER 3.0 .13 .15 .10 SCPER 5.0 .06 .09 .08 SCPER 8.0 .03 .03 .02 EXTRAC HEAD AE 0.5 END

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8) Create fatigue run file and run the analysis. Browse for results and using interactive fatigue to review critical joints.


Portion of spectral fatigue analysis report for joint 402L and 404L: ----------------------------------------------------------------------------------------------------------------------------------- * * * M E M B E R F A T I G U E R E P O R T * * * (DAMAGE ORDER) ORIGINAL CHORD REQUIRED JOINT MEMBER GRUP TYPE OD WT JNT MEM LEN. GAP * STRESS CONC. FACTORS * FATIGUE RESULTS OD WT ID ID (CM) (CM) TYP TYP (M ) (CM) AX-CR AX-SD IN-PL OU-PL DAMAGE LOC SVC LIFE (CM) (CM) 404L 402L-404L H41 TUB 30.38 1.250 Y BRC 12.12 3.05 6.00 2.32 3.36 3.959206 BL 5.051518 404L 404L-504L LG4 TUB 107.00 3.500 Y CHD 12.12 2.54 4.61 1.54 2.58 .9582906 BL 20.87050 404L 403L-404L H41 TUB 30.38 1.250 Y BRC 12.12 3.05 6.00 2.32 3.36 1.546541 BR 12.93208 404L 404L-504L LG4 TUB 107.00 3.500 Y CHD 12.12 2.54 4.61 1.54 2.58 .3436772 BR 58.19415 404L 404L-4000 H42 TUB 30.38 1.250 Y BRC 12.12 3.05 6.00 2.32 3.34 .5130308 BR 38.98401 404L 404L-504L LG4 TUB 107.00 3.500 Y CHD 12.12 2.54 4.58 1.54 2.56 .1025730 BR 194.9831 ---------------------------------------------------------------------------------------------------------------------------------- 402L 304L-402L D03 TUB 40.75 1.500 K BRC 12.12 32.00 2.70 2.63 2.78 2.07 .4098942 T 48.79308 402L 302L-402L LG3 TUB 107.00 3.500 K CHD 12.12 2.72 2.77 1.50 1.84 .1803190 TL 110.9146 402L 401L-402L H41 TUB 30.38 1.250 Y BRC 12.12 3.05 6.00 2.32 3.36 1.650136 BL 12.12021 402L 402L-502L LG4 TUB 107.00 3.500 Y CHD 12.12 2.54 4.61 1.54 2.58 .3789497 BL 52.77745 402L 402L-404L H41 TUB 30.38 1.250 K BRC 12.12 32.00 4.03 5.33 2.32 3.39 3.912909 TL 5.111287 402L 402L-502L LG4 TUB 107.00 3.500 K CHD 12.12 3.36 4.27 1.54 2.60 1.031002 TL 19.39861 402L 402L-4000 H43 TUB 30.38 1.250 Y BRC 12.12 3.05 6.00 2.32 3.34 .1221691 BL 163.7075 402L 402L-502L LG4 TUB 107.00 3.500 Y CHD 12.12 2.54 4.58 1.54 2.56 .0141106 BL 1417.369 -------------------------------------------------------------------------------------------------------------------------------------


9) Foundation pile fatigue analysis

Copy FTGINP.FTG to FTGINP.PIL, delete unrelated lines for pile fatigue analysis. JNTOVR, GRPSEL, JSLC, SCFSEL, RELIEF and EXTRAC line(s) will be deleted. Modify fatigue option line 2 and check “Tubular Inline Check”, chose American Welding Society S-N curve AWS for pile fatigue analysis. Modifying SCF limits line, Max. SCF =1.5 and Min. SCF = 1.0.

Pile Fatigue input file defined shall looks like following: ------------------------------------------------------------------------------------------------------------- FOUNDATION PILE FATIGUE INPUT FTOPT 2 20. 1.0 2. SMAPP MXMNSK LPEFT FTOPT2 PTVC AWS TI2 SCFLM 1.5 1.0 SEAS FTLOAD 1 .47 1.0 SPC SCATD D 1.0 1.0 PM SCWAV 0.30 1.0 2.0 SCPER 1.5 .15 .1 .1 SCPER 3.0 .1 .19 .11 SCPER 5.0 .05 .08 .05 SCPER 8.0 .02 .03 .02 FTLOAD 2 .20 1.0 SPC SCATD D 1.0 1.0 PM SCWAV 0.30 1.0 2.0 SCPER 1.5 .10 .13 .08 SCPER 3.0 .15 .13 .10 SCPER 5.0 .08 .08 .07 SCPER 8.0 .03 .02 .03 FTLOAD 3 .33 1.0 SPC SCATD D 1.0 1.0 PM SCWAV 0.30 1.0 2.0 SCPER 1.5 .13 .10 .08 SCPER 3.0 .13 .15 .10 SCPER 5.0 .06 .09 .08 SCPER 8.0 .03 .03 .02 END

------------------------------------------------------------------------------------------------------------- Create fatigue run file and run the analysis. Browse for results.


Portion of spectral fatigue analysis report for pile: ----------------------------------------------------------------------------------------------------------------------------------- * * * M E M B E R F A T I G U E R E P O R T * * * (DAMAGE ORDER) ORIGINAL CHORD REQUIRED JOINT MEMBER GRUP TYPE OD WT JNT MEM LEN. GAP * STRESS CONC. FACTORS * FATIGUE RESULTS OD WT ID ID (CM) (CM) TYP TYP (M ) (CM) AX-CR AX-SD IN-PL OU-PL DAMAGE LOC SVC LIFE (CM) (CM) 27 26- 27 PL1 TUB 91.50 2.500 1.50 1.50 1.50 1.50 .0130026 B 1538.155 27 27- 28 PL1 TUB 91.50 1.500 1.50 1.50 1.50 1.50 .2055976 B 97.27740 ---------------------------------------------------------------------------------------------------------------------------------- 427 426- 427 PL1 TUB 91.50 2.500 1.50 1.50 1.50 1.50 .0123253 T 1622.681 427 427- 428 PL1 TUB 91.50 1.500 1.50 1.50 1.50 1.50 .1905064 T 104.9833 ---------------------------------------------------------------------------------------------------------------------------------- 227 226- 227 PL2 TUB 91.50 2.500 1.50 1.50 1.50 1.50 .0113741 TL 1758.382 227 227- 228 PL2 TUB 91.50 1.500 1.50 1.50 1.50 1.50 .1648951 TL 121.2892 ---------------------------------------------------------------------------------------------------------------------------------- 627 626- 627 PL2 TUB 91.50 2.500 1.50 1.50 1.50 1.50 .0111565 BL 1792.682 627 627- 628 PL2 TUB 91.50 1.500 1.50 1.50 1.50 1.50 .1617696 BL 123.6326 ---------------------------------------------------------------------------------------------------------------------------------- 1 1- 2 PL1 TUB 91.50 2.500 1.50 1.50 1.50 1.50 .1201651 T 166.4376 ---------------------------------------------------------------------------------------------------------------------------------- 401 401- 402 PL1 TUB 91.50 2.500 1.50 1.50 1.50 1.50 .1131169 B 176.8082 ---------------------------------------------------------------------------------------------------------------------------------- 601 601- 602 PL2 TUB 91.50 2.500 1.50 1.50 1.50 1.50 .1055439 TR 189.4947

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Part 6 - Spectral Fatigue