Document No. SES1101213 PPT 001,Rev · 2013. 7. 29. · – Without 1/3rd increase in allowable for...

API 4F Design Study: ASD‐89 to LRFD‐05

Mike Effenberger, P.ESathish Ramamoorthy, Ph.D., P.E.June, 2012; PN 1101213

Preliminary subject to QA check

Document No. SES1101213‐PPT‐001,Rev.0a

2

Post Presentation Note

• This presentation was presented at the API Conference in Denver in the summer of 2012. After the presentation at the conference it was discovered that the SAP2000 conversion program had errors that were random in the converted SAP2000 file the models presented and for other rig models. The errors were in the element numbering system and load commands of the model. Due to these facts the comparison results might have errors and would provide results that could result in incorrect conclusions. Therefore numerical results have been removed.

3

SAP2000 Conversion Issues

• For one of the models a element numbering issue was discovered. StruCAD uses the two joint numbers for the primary numbering system of the members. SAP2000 uses element numbers for the members. One model had multiple members with the same joints. This issue cause an error in the SAP2000 conversion.

• For one of the load commands, an error in reading the format was discovered.

4

Contents

• API 4F Work • Background• Objectives• Design Study‐Methodology• Model Details• AISC‐05 Analysis Specifications• Rig 1 Design Study Results Detailed Design Results

• Rig 3 Design Study Results Detailed Design Results

5

API 4F

• API Funded Study – Check Effect of Load Factors for Drilling Structures• Paper – Code Conversion Issues Going From ASD to LRFD – Draft Provided

– Comments Due June 24• First Study Meeting – 2‐22‐2012

API 4F Work Group– Mark Trevithick (T&T Engineering) – Chair– Anthony Mannering (Precision Drilling)– Marcus McCoo (NOV)– Paul Landis (Lee C Moore)

First Load Factors – ASCE7 Models Received (last): 03/05/2012 Finish Work Date: 11/05/2012

6

API 4F Design Study‐Status6‐13‐2012

• Paper – Issued as Draft (Close 6-24-2012) Issue to API End of June• Rig 1 Boot-Strap Mast – Complete (Pending Review)

ASD-89 (StruCAD & SAP) ASD-05 – 1st Order & ASD-05- P-Delta LRFD-05

• Rig 3 Derrick ASD-89 & LRFD-05

• Rig 2 Mast & Substructure In progress – Duplicate Plate Element Issues (Removed)

• Rig 4 Dual Derrick – Duplicate Element Issue (Merging Elements)• Rig 5 Workover – Staad Model – Transfer Issues (Working with

Designer)

7

Background

• API 4F, Specification for Drilling and Well Servicing Structures states requirements and gives recommendations for suitable steel

structures for drilling and well‐servicing operations API 4F specifies the steel structures to be designed in accordance with

Allowable Stress Design/Elastic design per AISC 335‐89

• API 4F committee is interested in going from the Allowable Stress Design to the latest strength design Allowable Strength Design (ASD)/Load and Resistance Factor Design (LRFD) provision in AISC 360‐05 specification.

• Latest AISC specification is AISC 360‐10. The 2010 edition supersedes and is an update of the 2005 edition. The 2010 edition is yet to be supported by Computer Programs.

8

Background

• In the LRFD design methodology, design results are affected by the load factors selected for the individual loads (self weight, hook load, and environmental loads) For building design, load factors and load combinations are

specified in ASCE 7, Minimum Design Loads for Buildings and Other Structures

• The load factors are generally estimated using the statistical data for the individual loads and reliability concepts Statistical data for Hook load is not readily available. Therefore,

the load factors given in ASCE 7‐05 will be used for the design study (first case evaluation)

9

Objectives

• Paper documenting the experience of other codes/specification while changing from ASD to LRFD methodology

• Perform design study on six structures (workover, mast, derrick & substructure) designed using the ASD and LRFD design provisions.

• Hook load will be considered as live load with a load factor of 1.6 (ASCE 7, First Case Evaluation) Decided by the API 4F work group on 02/22/2012

10

Methodology

• Design performed using the Allowable Stress Design/Elastic Design provisions in AISC 335‐89 will be the base case.

• The structures will be evaluated according to AISC 335‐89 ASD and LRFD design provisions per AISC 360‐05 specification

• The design results between the Elastic design and Strength Design will be compared for evaluation

11

Derrick and Mast Models Provided to SES for Design Study

Model Name Type

Hook Load(kip)

No of Lines

SetBack(kip)

Height (ft)

Reference Wind Speed (knots)

Elevation from Water

Line(ft)Operating Unexpected Expected

Rig 1 Mast 441 10 xxx 92 42 70 93 102.5

Rig 2 Mast & Substructure 750 12 500 160 32 71.7 95.6 Land Rig

Rig 3 Single Derrick 1500 14 xxx 195 50 100 115 70

Rig 4 Dual Derrick25001500(Aux)

1614

(Aux)1750 242 65.1 xxx 100 83.7

Rig 5** Workover Mast 250 6 xxx 104 25 60 75 Land Rig

Notes:Analytical models for Rig1 to Rig 4 were developed in StruCADFor Rig 5, Analytical model was developed in STAAD

12

Rig 1441 kip Hook Load Mast

13

Rig 2750 kip Hook Load Mast & Substructure

Y

Z

X

Z

X Y

14

Rig 31500 kip Hook Load Single Derrick

X

Z

Y

Z

X Y

15

Rig 42500 kip Hook Load Dual Derrick

16

Rig 5250 kip Hook Load Workover Mast

17

Software Details

• SAP2000 Ultimate 15.1.0 from Computers and Structures, Inc (CSI) was used for the design study.

• SAP is a integrated software for structural analysis and design P‐Δ with large displacements Buckling analysis Design Codes

– ASD‐89– ASD‐05– LRFD‐05– LRFD‐10 (Later in 2012)

18

StruCAD to SAP2000 Conversion

• StruCAD models were imported in SAP. The imported models were compared with the StruCAD models.

• In general, most of the model features are imported without any issues. However, there are few StruCAD commands/features that are not imported in SAP. These are manually edited in the imported model.

• SAP technical support and development team were notified about the import issues.

19

StruCAD to SAP 2000 ConversionOutstanding issues

• Effective Length Factors not imported Effective length specified/used in the StruCAD model is entered as “Design Overwrites” in SAP model

• Wind Loads/Area Cards are not imported Wind loads are converted to Member and Joint Loads in StruCAD and imported in SAP

• Acceleration Loads Discrepancy in the base reactions for the acceleration loads in the StruCAD and SAP models. Therefore, the acceleration loads are converted to Member/joint loads in StruCAD and then imported in SAP

20

StruCAD to SAP 2000 ConversionDesign issues

• Cm factor Difference in calculating the Cm factor between StruCAD and SAP

• Brace Spacing StruCAD has option to input to the brace spacing for estimating the effective length. SAP does not have an equivalent parameter to modify

21

Design Basis

• AISC‐1989 Specification Allowable Stress Design (ASD‐89)

• AISC‐2005 Specification Load and Resistance Factor Design (LRFD‐05)

22

Design BasisAllowable Stress Design‐89

• The imported models were run in SAP and compared with the StruCAD results In general, the member forces are comparable to the StruCAD member forces. For some members, there is a small discrepancy in the minor and major axis moments.

• Allowable Stress Design (ASD‐89)– Static linear analysis– With 1/3rd increase in allowable stress for expected and

unexpected load case

23

Design BasisAllowable Strength Design‐05

For Rig 1 Only• Allowable Strength Design (ASD‐05)

– Effective length method– Second order analysis method (includes p‐Δ and p‐δ)– Without 1/3rd increase in allowable for wind load combinations– API 4F load combinations

Case Design Loading Dead Load Hook Load Rotary Load Setback Load Environmental LoadsCondition (%) (%) (%) (%) (%)

1a Operating 100 100 0 100 1001b Operating 100 TE*100% 100 100 1002 Expected 100 TE*100% 100 0 1003a Unexpected 100 TE*100% 100 100 1003b* Unexpected 100 ‐ ‐ ‐ ‐4 Erection 100 100 0 0 1005 Transportation 100 100 0 100 100

Note: Load combination 3b is for Earthquake loads and was not included in this study

24

Design BasisLoad and Resistance Factor Design ‐05

• Load and Resistance Factor Design (LRFD‐05)– Effective length method– General second order analysis method (includes p‐Δ and p‐δ)– Without 1/3rd increase in allowable for wind load combinations– Hook load is considered as live load with 1.6 load factor similar to

ASCE 7‐05 live loads

Case Design Loading Dead Load Hook Load Rotary Load Setback Load Environmental LoadsCondition (%) (%) (%) (%) (%)

1a Operating 120 160 0 160 1001b Operating 120 TE*160% 120 120 1002 Expected 120 TE*100% 100 0 1603a Unexpected 120 TE*100% 100 100 1603b Unexpected 120 ‐ ‐ ‐ ‐4 Erection 120 160 0 0 1005 Transportation 120 160 0 160 100

Note: Other loads should be classified (for ex loads in Rig 3 Model

25

Comparison of Analysis MethodsAISC‐05 Specification

Direct Analysis Method

Effective Length Method

First‐Order Analysis Method

Specification Reference Appendix 7 Section C.2.2a Section C.2.2b

Limits on Applicability No Yes Yes

Type of analysis Second‐Order Second‐Order First‐Order

Member stiffness Reduced EI and EA Nominal EI and EA Nominal EI and EA

Notional lateral load Yes Yes Yes

Column effective length K=1 Sidesway buckling analysis

K=1

Note: In AISC‐10 specification, Direct Analysis is moved to Section C. Effective length and Firs‐Order Analysis Methods are moved to Appendix 7

26

Comparison of Analysis Methods

Direct Analysis Method


First‐Order Analysis Method

Specification Reference Appendix 7 Section C.2.2a Section C.2.2b

Limits on Applicability No Yes Yes

Type of analysis Second‐Order Second‐Order First‐Order

Member stiffness Reduced EI and EA Nominal EI and EA Nominal EI and EA

Notional lateral load Yes Yes Yes

Column effective length K=1 Sidesway buckling analysis

K=1

Not considered in this study

27

Effective Length Method Details


Amplified First Order

Linear Load combinationNo P‐DeltaK=1Force effects are amplified by B1 and B2 factor to account for P‐Delta**

General Second Order

Non‐linear load combinationP‐deltaEffective length from StruCAD model (side sway buckling analysis was not performed)Notional lateral load for gravity load combinations is not included

** B1 and B2 factors account for the P‐δ and P‐Δ. For the current API 4F study, to study the effect of changes in the specification for member strength, the B1 and B2 factor of 1.0 was used. Comparison of design results between the ASD‐05 (First order) and ASD‐89 will show the effect of changes in specifications.

28

Rig 1 Design Study Results(Boot Strap Mast)

• Total number of Members 347 (excluding 16 dummy members)

• SAP classifies the members Beams (all elements parallel to the X‐Y plane)

– 184

Brace (all elements not classified as beams or columns)– 85

Column (all elements parallel to the Z‐axis)– 78

29

Rig 1441 kip Hook Load Mast

Rig 1 Rig 1Beams184

Rig 1Braces85

Rig 1Columns78

30

Rig 1‐ Design Study Results441 kip Hook Load Mast

Allowable Stress Design (ASD‐89) StruCAD

Allowable Stress Design (ASD‐89)

SAP

Allowable Stress Design (ASD‐89)

SAP

Allowable Strength Design (ASD‐05)Amplified First Order Method**

Allowable Strength Design

(ASD‐05)

Load and Resistance

Factor Design(LRFD‐05)(ASCE 7)

Members with unity ratio > 1.0

Type of analysis

First‐Order First‐Order Fist‐Order First‐Order Second‐Order(P‐Δ and P‐δ)Second‐Order(P‐Δ and P‐δ)

1/3rdAllowable Stress Increase

Yes Yes No No No No

Note: **The amplified first order method is modified (B1, B2 =1) to compare the difference in design results between ASD ‐89 and ASD‐05

specifications

31

Rig 1 Design Study ResultsUnity Check Statistics

BeamASD‐89 LRFD‐05 % change

No of members with UC >1Maximum UCAverage UC

BraceASD‐89 LRFD‐05 % change

ColumnASD‐89 LRFD‐05 % change

Notes1.SAP ASD‐89 results are with 1/3rd increase in Allowable Stress for Expected and Unexpected Storm2.LRFD‐05 results are without 1/3rd increase. Load factor for Hook Load is 1.63.Even without the 1/3rd stress increase for LRFD‐05, there is no significant increase in number of members exceeding the unity check ratio4.The significant change in UC for beam member from ASD‐89 to LRFD‐05 is due to the difference in the interaction equation for doubly symmetric members in LRFD specification 5.Detailed results for the highest UC members for beam, brace and column are provided in detailed results section

SAP Models‐ ASD‐89 and LRFD‐05

32

Rig 1‐ Design Study ResultsASD‐89 StruCAD and SAP

ASD‐89‐StruCAD Modelmembers with UR > 1.

With 1/3rd Stress Increase for Expected and Unexpected Storm


StruCAD model Import into SAP2000Design with

AISC‐89 specification with

1/3rd Stress Increase

ASD‐89‐SAP modelmembers with UR > 1.

Member No Load Comb Unity Ratio Member No Load Comb Unity RatioColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnBraceBraceBeamBeamBeamBeam

33

Rig 1‐ Design Study ResultsASD‐89 SAP

ASD‐89‐SAP Modelmembers with UR > 1.


Without 1/3rd Stress Increase for Expected and Unexpected Storm

AISC‐89 specification Design resultswithout the

1/3rd Stress Increase

ASD‐89‐SAP modelmembers with UR > 1.

Member No Load Comb Unity Ratio Member No Load Comb Unity RatioBraceBraceColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnBraceBraceBeamBeamBeamBeam

34

Rig 1‐ Design Study ResultsASD‐89 and ASD‐05 First Order

ASD‐89‐SAPmembers with UR > 1.

ASD‐05‐SAP Amplified First Ordermembers with UR > 1.



Transition from AISC‐89 specification to AISC‐05 specification

Member No Load Comb Unity RatioBraceBraceColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnBraceBraceBeamBeamBeamBeam

Member No Load Comb Unity Ratio

35

Rig 1‐ Design Study ResultsASD‐89 and ASD‐05 First Order

ASD‐89‐SAPmembers with UR > 1.

ASD‐05‐SAP Amplified First Ordermembers with UR > 1.



Transition from AISC‐89 specification to AISC‐05 specification

Member No Load Comb Unity Ratio Member No Load Comb Unity RatioBraceBraceColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnBraceBraceBeamBeamBeamBeam

36

Rig 1‐ Design Study ResultsSAP Models: ASD‐89, ASD‐05 First order and ASD‐05

ASD‐89members with UR > 1.0

ASD‐05‐Amplified First Ordermembers with UR > 1.0




Member No Load Comb Unity RatioBraceBraceColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnBraceBraceBeamBeamBeamBeam

Member No Load Comb Unity Ratio Member No Load Comb Unity Ratio

37

Rig 1‐ Design Study ResultsSAP Models: ASD‐89, ASD‐05 and LRFD‐05



LRFD‐05members with UR > 1.0



Member No Load Comb Unity Ratio Member No Load Comb Unity Ratio Member No Load Comb Unity RatioBraceBraceColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnBraceBraceBeamBeamBeamBeamBeamBeamBeam

38

Rig 1‐ Design Study ResultsSAP Models: ASD‐89, ASD‐05 and LRFD‐05



LRFD‐05members with UR > 1.0



Member No Load Comb Unity Ratio Member No Load Comb Unity RatioBraceBraceColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnColumnBraceBraceBeamBeamBeamBeamBeamBeamBeam

Member No Load Comb Unity Ratio

39

Rig 1Detailed Design Results for Selected

Members

40

Rig 1Detailed Design Results for Selected Members• Beam• Brace• Column

41

Rig 1 Detailed Design Results Members

Rig 1BeamsMember # 313

Rig 1BraceMember # 285

Rig 1Column Member # 274

42


43

Rig 1Beam Member 313‐Loads and Design Calculations

Design Combo Location Pr MrMajor MrMinor VrMajor VrMinor Tr Equation TotalRatio PRatio MMajRatio MMinRatioOption Text in Kip Kip‐in Kip‐in Kip Kip Kip‐in Text Unitless Unitless Unitless Unitless

ASD‐89* 27ASD‐89 SCAD27ASD‐05** SCAD27ASD‐05 SCAD27LRFD‐05 SCAD27

* StruCAD results** First Order Results (no P‐Δ)ASD‐05 and LRFD‐05 results are without the 1/3rd increase in allowable stress

Member 313Joint A: 172Joint B: 173Section: T8D

44

Member No. 313 172‐ 173 Joint Thickness 0 Actual StressesGRUP T8D Slenderness coeff. Ky 0.9 Axial Stress fa ‐0.432Section ‐ TS8X4X3/16 Slenderness coeff. Kz 0.9 Bending Stress Top fbyt ‐10.835Total Length ‐7.5 Effective Length Ly 7.5 Bending Stress Bot fbyb 10.835Load Case 27 Effective Length Lz 11 Bending Stress Lft fbzl 0.707Distance 0 Brace Spacing 7.5 Bending Stress Rht fbzr ‐0.707Segment 1 Tub. Mod. / Stiff. Spacing 7.5 Shear Stress fvy ‐0.02Design Code SA9 Shear Stress fvz ‐0.597

Forces & Moments Tors. Shear Stress fvyt ‐1.216Amod 1.333 Axial Force Fx ‐1.844 Tors. Shear Stress fvzt ‐1.216Cmy C Shear Force Fy ‐0.03 Combined Shear Stress fv 1.814Cmz C Shear Force Fz ‐1.792 Warping Normal Stress Fbztr 0Cb B Torsional Moment Mx ‐13.587 Combined Stress fcomb ‐11.974Yield Strength 46 Bending Moment My 95.618 0Skip Local Buckling Checks Bending Moment Mz 4.244Basic PropertiesSection Type BOX Governing Equations Allowable Stresses Unity RatiosAxial Area 4.27 Critical Buckling (API) Fxcr Euler Stress F'ey 251.65Tors. Constant J 29.1 Tension Allowable Fat (SEC D1) Euler Stress F'ez 39.808Max. Unbraced Length Lc 7.473 Compression Allowable Fac (E 2‐1) Critical Buckling (API) Fxcr 0Max. Unbraced Length Lu 0 Bending Tension Allow. Fbyt (F 3‐3) Tension Allowable Fat 36.791Sect. Modulus Top Syt 8.825 Bending Compression Allow Fbyc (F 3‐3) Compression Allowable Fac 26.167 Axial Component Ua 0.017Sect. Modulus Bot Syb 8.825 Bending Tension Allow. Fbzt (F 3‐3) Bending Tension Allow. Fbyt 36.791 Bending Component Uby 0.294Sect. Modulus Lft Szl 6 Bending Compression Allow Fbzc (F 3‐3) Bending Compression Allow Fbyc 36.791 Bending Component Ubz 0.019Sect. Modulus Rht Szr 6 Shear Allowable Fvay (F 4‐1) Bending Tension Allow. Fbzt 36.791 Shear Component Usy 0.05Slenderness ratio Kl/ry 28.125 Shear Allowable Fvaz (F 4‐1) Bending Compres. Allow Fbzc 36.791 Shear Component Usz 0.074Slenderness ratio Kl/rz 70.714 Combined Unity Ratio Uc (H1‐3) Shear Allowable Fvay 24.527 Combined Unity Ratio Uc 0.33Col. Slenderness Ratio Cc 111.554 Shear Allowable Fvaz 24.527 Critical Unity Ratio Uc 0.33Interaction Coefficient Cmy 0.325Interaction Coefficient Cmz 0.236Bending Coefficient Cb 2.3

Rig 1 ASD‐89‐StruCADBeam Member 313, U.C Ratio = 0.33

45

Rig 1 ASD‐89‐SAPBeam Member 313, U.C Ratio =

46

Rig 1 LRFD‐05 SAPBeam Member 313, U.C Ratio =

47


48

Rig 1Brace Member 285‐Loads and Design Calculations




Member 285Joint A: 3Joint B: 246Section: T8A

49

Rig 1 ASD‐89‐StruCADBrace Member 285, U.C Ratio = 0.719

Member No. 285 3‐ 246 Joint Thickness 1 Actual StressesGRUP T8A Slenderness coeff. Ky 1 Axial Stress fa ‐10.72Section ‐ TS8X8X3/8 Slenderness coeff. Kz 1 Bending Stress Top fbyt 1.026Total Length ‐31.545 Effective Length Ly 27 Bending Stress Bot fbyb ‐1.026

Load Case 42 Effective Length Lz 27 Bending Stress Lft fbzl 1.949Distance 15.7723 Brace Spacing 31.545 Bending Stress Rht fbzr ‐1.949Segment 1 Tub. Mod. / Stiff. Spacing 31.545 Shear Stress fvy 0.001Design Code SA9 Shear Stress fvz 0

Forces & Moments Tors. Shear Stress fvyt 0Amod 1.333 Axial Force Fx ‐118.991 Tors. Shear Stress fvzt 0Cmy C Shear Force Fy 0.003 Combined Shear Stress fv 0.001Cmz C Shear Force Fz ‐0.003 Warping Normal Stress Fbztr 0Cb B Torsional Moment Mx 0 Combined Stress fcomb ‐13.695Yield Strength 46 Bending Moment My ‐27.187 0Skip Local Buckling Checks Bending Moment Mz 51.65Basic PropertiesSection Type BOX Governing Equations Allowable Stresses Unity RatiosAxial Area 11.1 Critical Buckling (API) Fxcr Euler Stress F'ey 18.105Tors. Constant J 170 Tension Allowable Fat (SEC D1) Euler Stress F'ez 18.105Max. Unbraced Length Lc 14.946 Compression Allowable Fac (E 2‐1) Critical Buckling (API) Fxcr 0Max. Unbraced Length Lu 0 Bending Tension Allow. Fbyt (F 3‐3) Tension Allowable Fat 36.791Sect. Modulus Top Syt 26.5 Bending Compression Allow Fbyc (F 3‐3) Compression Allowable Fac 17.872 Axial Component Ua 0.6Sect. Modulus Bot Syb 26.5 Bending Tension Allow. Fbzt (F 3‐3) Bending Tension Allow. Fbyt 36.791 Bending Component Uby 0.041Sect. Modulus Lft Szl 26.5 Bending Compression Allow Fbzc (F 3‐3) Bending Compression Allow Fbyc 36.791 Bending Component Ubz 0.078Sect. Modulus Rht Szr 26.5 Shear Allowable Fvay (F 4‐1) Bending Tension Allow. Fbzt 36.791 Shear Component Usy 0Slenderness ratio Kl/ry 104.854 Shear Allowable Fvaz (F 4‐1) Bending Compres. Allow Fbzc 36.791 Shear Component Usz 0Slenderness ratio Kl/rz 104.854 Combined Unity Ratio Uc (H1‐1) Shear Allowable Fvay 24.527 Combined Unity Ratio Uc 0.719Col. Slenderness Ratio Cc 111.554 Shear Allowable Fvaz 24.527 Critical Unity Ratio Uc 0.719Interaction Coefficient Cmy 0.6Interaction Coefficient Cmz 0.6Bending Coefficient Cb 1.75

50

Rig 1 ASD‐89‐SAPBrace Member 285, U.C Ratio =

51

Rig 1 LRFD‐05‐SAPBrace Member 285, U.C Ratio =

52


53

Rig 1Column Member 274‐Loads and Design Calculations




Member 274Joint A: 124Joint B: 128Section: T6U

54

Rig 1 ASD‐89‐StruCADColumn Member 274, U.C Ratio = 1.016

Member No. 274 124‐ 128 Joint Thickness 0 Actual StressesGRUP T6U Slenderness coeff. Ky 1 Axial Stress fa ‐23.491Section ‐ TS6X6X3/8 Slenderness coeff. Kz 0.9 Bending Stress Top fbyt ‐1.389Total Length ‐7.443 Effective Length Ly 9.1 Bending Stress Bot fbyb 1.389Load Case 18 Effective Length Lz 7 Bending Stress Lft fbzl ‐2.958Distance 0 Brace Spacing 7.443 Bending Stress Rht fbzr 2.958Segment 1 Tub. Mod. / Stiff. Spacing 7.443 Shear Stress fvy 0.21Design Code SA9 Shear Stress fvz ‐0.059

Forces & Moments Tors. Shear Stress fvyt 0.552Amod 1 Axial Force Fx ‐189.804 Tors. Shear Stress fvzt 0.552Cmy C Shear Force Fy 0.945 Combined Shear Stress fv 0.762Cmz C Shear Force Fz ‐0.268 Warping Normal Stress Fbztr 0Cb B Torsional Moment Mx 13.102 Combined Stress fcomb ‐27.838Yield Strength 50 Bending Moment My 19.262 0Skip Local Buckling Checks Bending Moment Mz ‐41.019Basic PropertiesSection Type BOX Governing Equations Allowable Stresses Unity RatiosAxial Area 8.08 Critical Buckling (API) Fxcr Euler Stress F'ey 64.529Tors. Constant J 68.5 Tension Allowable Fat (SEC D1) Euler Stress F'ez 134.635Max. Unbraced Length Lc 9.75 Compression Allowable Fac (E 2‐1) Critical Buckling (API) Fxcr 0Max. Unbraced Length Lu 0 Bending Tension Allow. Fbyt (F 3‐1) Tension Allowable Fat 30Sect. Modulus Top Syt 13.867 Bending Compression Allow Fbyc (F 3‐1) Compression Allowable Fac 24.643 Axial Component Ua 0.953Sect. Modulus Bot Syb 13.867 Bending Tension Allow. Fbzt (F 3‐1) Bending Tension Allow. Fbyt 33 Bending Component Uby 0.036Sect. Modulus Lft Szl 13.867 Bending Compression Allow Fbzc (F 3‐1) Bending Compression Allow Fbyc 33 Bending Component Ubz 0.026Sect. Modulus Rht Szr 13.867 Shear Allowable Fvay (F 4‐1) Bending Tension Allow. Fbzt 33 Shear Component Usy 0.038Slenderness ratio Kl/ry 48.106 Shear Allowable Fvaz (F 4‐1) Bending Compres. Allow Fbzc 33 Shear Component Usz 0.031Slenderness ratio Kl/rz 33.304 Combined Unity Ratio Uc (H1‐1) Shear Allowable Fvay 20 Combined Unity RatioUc 1.016Col. Slenderness Ratio Cc 106.999 Shear Allowable Fvaz 20 Critical Unity Ratio Uc 1.016Interaction Coefficient Cmy 0.548Interaction Coefficient Cmz 0.24Bending Coefficient Cb 1.892

55

Rig 1 ASD‐89‐SAPColumn Member 274, U.C Ratio =

56

Rig 1 LRFD‐05 SAPColumn Member 274, U.C Ratio =

57

Rig 3 Design Study Results(Derrick)

• Total number of Members 1420 (excluding 125 dummy members)

• SAP classifies the members Beams (all elements parallel to the X‐Y plane)

– 949

Brace (all elements not classified as beams or columns)– 231

Column (all elements parallel to the Z‐axis)– 246

58

Rig 31500 kip Hook Load Single Derrick

Rig 3Rig 3Beams949

Rig 3Braces231

Rig 3Columns246

59

Rig 3 Design Study ResultsUnity Check Statistics

BeamASD‐89 LRFD‐05 % change

No of members with UC >1Maximum UCAverage UC

BraceASD‐89 LRFD‐05 % change

ColumnASD‐89 LRFD‐05 % change

Notes1. ASD‐89 results are with 1/3rd increase in Allowable stress for Expected and Unexpected Storm2. LRFD‐05 results are without 1/3rd increase. Load factor for Hook Load is 1.63. For LRFD‐05, without the 1/3rd stress increase for LRFD‐05, there is an increase in number of

column members exceeding the unity check ratio4. Detailed design calculations for the highest UC members for beam, brace and column are

provided in detailed results section

SAP Models‐ ASD‐89 and LRFD‐05

60

Rig 3‐ Design Study ResultsSAP Models: ASD‐89 and LRFD‐05

ASD‐89members

with UR > 1.0

LRFD‐05members

with UR > 1.0

With 1/3rd Stress Increase for

Expected and Unexpected Storm


Member No Load Comb Unity Ratio Member No Load Comb Unity Ratio

61

Rig 3Detailed Design Results for Selected

Members

62


63

Rig 3 Detailed Design Results Members

Rig 3BeamsMember # 796

Rig 3BraceMember # 87

Rig 3Column Member # 15

64


65

Rig 3Beam Member 796‐Loads and Design Calculations


ASD‐89*ASD‐89LRFD‐05

* StruCAD results** First Order Results (no P‐Δ)LRFD‐05 results are without the 1/3rd increase in allowable stress

Member 796Joint A: 135Joint B: 92Section: GS2

66

Rig 3 ASD‐89‐StruCADBeam Member 796, U.C Ratio = 0.777

Member No. 796 135‐ 92 Joint Thickness 0 Actual StressesGRUP GS2 Slenderness coeff. Ky 1 Axial Stress fa ‐7.56Section ‐W14X30 Slenderness coeff. Kz 1 Bending Stress Top fbyt ‐3.055Total Length ‐14.08 Effective Length Ly 28.156 Bending Stress Bot fbyb 3.055

Load Case 64 Effective Length Lz 14.078 Bending Stress Lft fbzl ‐2.508Distance 14.078 Brace Spacing 14.078 Bending Stress Rht fbzr 2.508Segment 1 Tub. Mod. / Stiff. Spacing 14.078 Shear Stress fvy 0.007Design Code SA9 Shear Stress fvz 0.251

Forces & Moments Tors. Shear Stress fvyt 0Amod 1 Axial Force Fx ‐66.906 Tors. Shear Stress fvzt 0Cmy C Shear Force Fy 0.023 Combined Shear Stress fv 0.251Cmz C Shear Force Fz 0.938 Warping Normal Stress Fbztr 0.003Cb B Torsional Moment Mx ‐0.002 Combined Stress fcomb ‐13.126Yield Strength 50 Bending Moment My 128.458 0Skip Local Buckling Checks Bending Moment Mz ‐14.609Basic PropertiesSection Type WF Governing Equations Allowable Stresses Unity RatiosAxial Area 8.85 Critical Buckling (API) Fxcr Euler Stress F'ey 42.949Tors. Constant J 0.38 Tension Allowable Fat (SEC D1) Euler Stress F'ez 11.617Max. Unbraced Length Lc 6.028 Compression Allowable Fac (E 2‐2) Critical Buckling (API) Fxcr 0Max. Unbraced Length Lu 9.29 Bending Tension Allow. Fbyt (F 1‐5) Tension Allowable Fat 30Sect. Modulus Top Syt 42.052 Bending Compression Allow Fbyc (F 1‐6) Compression Allowable Fac 11.617 Axial Component Ua 0.651Sect. Modulus Bot Syb 42.052 Bending Tension Allow. Fbzt (F 2‐1) Bending Tension Allow. Fbyt 30 Bending Component Uby 0.07Sect. Modulus Lft Szl 5.825 Bending Compression Allow Fbzc (F 2‐1) Bending Compression Allow Fbyc 26.756 Bending Component Ubz 0.056Sect. Modulus Rht Szr 5.825 Shear Allowable Fvay (F 4‐1) Bending Tension Allow. Fbzt 37.5 Shear Component Usy 0Slenderness ratio Kl/ry 58.965 Shear Allowable Fvaz (F 4‐1) Bending Compres. Allow Fbzc 37.5 Shear Component Usz 0.013Slenderness ratio Kl/rz 113.38 Combined Unity Ratio Uc (H1‐1) Shear Allowable Fvay 20 Combined Unity Ratio Uc 0.777Col. Slenderness Ratio Cc 106.999 Shear Allowable Fvaz 20 Critical Unity Ratio Uc 0.777Interaction Coefficient Cmy 0.506Interaction Coefficient Cmz 0.294Bending Coefficient Cb 2.012

67

Rig 3 ASD‐89‐SAPBeam Member 796, U.C Ratio =

68

Rig 1 LRFD‐05 SAPBeam Member 796, U.C Ratio =

69


70

Rig 3Brace Member 87‐Loads and Design Calculations


ASD‐89* 90ASD‐89 SCAD90LRFD‐05 SCAD90


Member 87Joint A: 140Joint B: 68Section: B4S

71

Rig 3 ASD‐89‐StruCADBrace Member 87, U.C Ratio = 0.680

Member No. 87 140‐ 68 Joint Thickness 0 Actual StressesGRUP B4S Slenderness coeff. Ky 1 Axial Stress fa ‐9.729Section ‐W14X61 Slenderness coeff. Kz 1 Bending Stress Top fbyt 1.833Total Length ‐23.05 Effective Length Ly 23.049 Bending Stress Bot fbyb ‐1.833

Load Case 90 Effective Length Lz 23.049 Bending Stress Lft fbzl ‐0.718Distance 15.3659 Brace Spacing 23.049 Bending Stress Rht fbzr 0.718Segment 1 Tub. Mod. / Stiff. Spacing 23.049 Shear Stress fvy 0.011Design Code SA9 Shear Stress fvz ‐0.186

Forces & Moments Tors. Shear Stress fvyt 0.009Amod 1.33 Axial Force Fx ‐174.145 Tors. Shear Stress fvzt ‐0.005Cmy C Shear Force Fy 0.093 Combined Shear Stress fv 0.191Cmz C Shear Force Fz ‐0.967 Warping Normal Stress Fbztr 0.005Cb B Torsional Moment Mx ‐0.046 Combined Stress fcomb ‐12.276Yield Strength 50 Bending Moment My ‐168.961 0Skip Local Buckling Checks Bending Moment Mz ‐15.378Basic PropertiesSection Type WF Governing Equations Allowable Stresses Unity RatiosAxial Area 17.9 Critical Buckling (API) Fxcr Euler Stress F'ey 92.842Tors. Constant J 2.2 Tension Allowable Fat (SEC D1) Euler Stress F'ez 15.584Max. Unbraced Length Lc 8.952 Compression Allowable Fac (E 2‐2) Critical Buckling (API) Fxcr 0Max. Unbraced Length Lu 15.471 Bending Tension Allow. Fbyt (F 1‐5) Tension Allowable Fat 39.9Sect. Modulus Top Syt 92.153 Bending Compression Allow Fbyc (F 1‐6) Compression Allowable Fac 15.584 Axial Component Ua 0.624Sect. Modulus Bot Syb 92.153 Bending Tension Allow. Fbzt (F 2‐1) Bending Tension Allow. Fbyt 39.9 Bending Component Uby 0.03Sect. Modulus Lft Szl 21.411 Bending Compression Allow Fbzc (F 2‐1) Bending Compression Allow Fbyc 39.9 Bending Component Ubz 0.026Sect. Modulus Rht Szr 21.411 Shear Allowable Fvay (F 4‐1) Bending Tension Allow. Fbzt 49.875 Shear Component Usy 0.001Slenderness ratio Kl/ry 46.252 Shear Allowable Fvaz (F 4‐1) Bending Compres. Allow Fbzc 49.875 Shear Component Usz 0.007Slenderness ratio Kl/rz 112.892 Combined Unity Ratio Uc (H1‐1) Shear Allowable Fvay 26.6 Combined Unity Ratio Uc 0.68Col. Slenderness Ratio Cc 106.999 Shear Allowable Fvaz 26.6 Critical Unity Ratio Uc 0.68Interaction Coefficient Cmy 0.585Interaction Coefficient Cmz 0.671Bending Coefficient Cb 1.789

72

Rig 3 ASD‐89‐SAPBrace Member 87, U.C Ratio =

73

Rig 3 LRFD‐05‐SAPBrace Member 87, U.C Ratio =

74


75

Rig 3Column Member 15‐Loads and Design Calculations


ASD‐89* 53ASD‐89 SCAD53LRFD‐05 SCAD53


Member 15Joint A: 66Joint B: 70Section: 1LG

76

Rig 3 ASD‐89‐StruCADColumn Member 15, U.C Ratio = 0.942

Member No. 15 66‐ 70 Joint Thickness 0 Actual StressesGRUP 1LG Slenderness coeff. Ky 1 Axial Stress fa ‐23.842Section ‐W14X120 Slenderness coeff. Kz 1 Bending Stress Top fbyt 1.433Total Length ‐15 Effective Length Ly 15 Bending Stress Bot fbyb ‐1.433

Load Case 53 Effective Length Lz 15 Bending Stress Lft fbzl ‐1.073Distance 0 Brace Spacing 15 Bending Stress Rht fbzr 1.073Segment 1 Tub. Mod. / Stiff. Spacing 15 Shear Stress fvy 0.018Design Code SA9 Shear Stress fvz 0.354

Forces & Moments Tors. Shear Stress fvyt 0.002Amod 1 Axial Force Fx ‐841.632 Tors. Shear Stress fvzt 0Cmy C Shear Force Fy 0.34 Combined Shear Stress fv 0.354Cmz C Shear Force Fz 3.027 Warping Normal Stress Fbztr 0.034Cb B Torsional Moment Mx 0.247 Combined Stress fcomb ‐26.314Yield Strength 55 Bending Moment My ‐273.164 0Skip Local Buckling Checks Bending Moment Mz ‐72.421Basic PropertiesSection Type WF Governing Equations Allowable Stresses Unity RatiosAxial Area 35.3 Critical Buckling (API) Fxcr Euler Stress F'ey 179.463Tors. Constant J 9.37 Tension Allowable Fat (SEC D1) Euler Stress F'ez 64.469Max. Unbraced Length Lc 12.528 Compression Allowable Fac (E 2‐1) Critical Buckling (API) Fxcr 0Max. Unbraced Length Lu 28.859 Bending Tension Allow. Fbyt (F 1‐5) Tension Allowable Fat 33Sect. Modulus Top Syt 190.608 Bending Compression Allow Fbyc (F 1‐8) Compression Allowable Fac 26.704 Axial Component Ua 0.893Sect. Modulus Bot Syb 190.608 Bending Tension Allow. Fbzt (F 2‐1) Bending Tension Allow. Fbyt 33 Bending Component Uby 0.013Sect. Modulus Lft Szl 67.485 Bending Compression Allow Fbzc (F 2‐1) Bending Compression Allow Fbyc 33 Bending Component Ubz 0.036Sect. Modulus Rht Szr 67.485 Shear Allowable Fvay (F 4‐1) Bending Tension Allow. Fbzt 41.25 Shear Component Usy 0.001Slenderness ratio Kl/ry 28.846 Shear Allowable Fvaz (F 4‐1) Bending Compres. Allow Fbzc 41.25 Shear Component Usz 0.016Slenderness ratio Kl/rz 48.128 Combined Unity Ratio Uc (H1‐1) Shear Allowable Fvay 22 Combined Unity Ratio Uc 0.942Col. Slenderness Ratio Cc 102.019 Shear Allowable Fvaz 22 Critical Unity Ratio Uc 0.942Interaction Coefficient Cmy 0.251Interaction Coefficient Cmz 0.848Bending Coefficient Cb 2.3

77

Rig 3 ASD‐89‐SAPColumn Member 15, U.C Ratio =

78

Rig 3 LRFD‐05 SAPColumn Member 15, U.C Ratio =

79

Contact InformationMike Effenberger, [email protected]

Sathish Ramamoorthy, [email protected]

Stress Engineering Services13800 Westfair East DriveHouston, Texas 77041

Phone: (281) 955‐2900Fax: (281) 955‐2638www.stress.com

Document No. SES1101213 PPT 001,Rev · 2013. 7. 29. · – Without 1/3rd increase in allowable for...

Documents

Transcript of Document No. SES1101213 PPT 001,Rev · 2013. 7. 29. · – Without 1/3rd increase in allowable for...