TECHCRANE_CRANE_STABILITY_CALCUALTIONS.pdf

CRANE STABILITY CALCULATIONS

TECHCRANE CARNE MODEL :T80-62-82

CUSTOMER: BASIC MARINE

Techcrane International LLC. 17639 Hard Hat Dr. Covinton , LA 70435 B:+01(985)871-0056 F:+01 (985) 871-0065 www.techcrane.com

TABLE OF CONTENT

SECTION1 : PEDESTAL DIMENSION

SECTION 2 : ASSUMPTIONS

SECTION 3 : PEDESTAL CONE CALCULATION PER API -RP -2A

1. PEDESTAL CONE CALCULATION PER API -RP -2A FOR MAX MOEMTT WITH

CORESPONDEING THRUST.

SECTION 4 : PEDESTAL SIMULATION RESULTS

1. FEA ANALYSIS ON PEDESTAL ASSEMBLY.

2. FATIGUE ANALYSIS PER API 2C 7TH EDITION.

SECTION 1

PEDESTAL GEOMETRY

T80-62-82

A A

B B

C C

D D

SHEET 1 OF 1

DESIGNED BY:

DRAWN BY:

WEIGHT:

PART/DWG. NO.:

FILE NAME:

U:\Design_Packages\80 - SERIES CRANES\1 - DESIGN\3 - FEA ANALYSIS\3 - PEDESTAL\T80-62-82\Pedestal cone assembly with flange.iam afarah lbaylis

TAPERED PEDESTAL 60" - 66"

DATE:

17639 HARD HAT DRIVE COVINGTON, LA. 70435 U.S.A.

PHONE (985) 871-0056 FAX (985) 871-0065

REVISION NO.:

3/26/2013

INFORMATION CONTAINED HEREON IS

CONFIDENTIAL AND TRADE SECRET

DO NOT DISCLOSE, USE OR REPRODUCE

WITHOUT PRIOR WRITTEN APPROVAL

FROM TECHCRANE INTERNATIONAL LLC.

N/A

MATERIAL:

Steel, High Strength Low Alloy

WorkInProgress

DESIGN STATE:

MATERIAL NOTES:

1. BURN PER DIMENTIONS SHOWN.

2. PLATE FLATNESS AFTER BURNING TO BE

WITHIN ASTM SPECIFICATIONS.

3. REFER TO API SPEC 2C LATEST EDITION.

4. WHERE APPLICABLE - ROLL FORM PER

DIMENSIONS SHOWN.

5. WHERE APPLICABLE - TACK WELD AS

REQUIRED TO SECURE ROLLED CAN.

UNLESS OTHERWISE SPECIFIED

ALL DIMENSIONS ARE IN INCHES

[] INDICATES MILLIMETERS

TOLLERANCES

FRACTIONAL DIMENSIONS +

16/-0

SURFACE FINISHES 125√

REVISION HISTORY

SHEET REV DESCRIPTION DATE APPROVED

22 1/2

SECTION 2

ASSUMPTIONS

ASSUMPTIONS:

The true moment on the pedestal structure is calculated as 2526.293 ft-lbs with corresponding thrust load 79348 lbs as it is shown on the table below :

Reach (Feet)

Boom Angle (Deg) Moment (ft-lbs.) Axial Load

(Pounds) 80 12.7 2,526,293 79,348

The above value are calculated based on the (1x Static load + Crane dead weight)*(Boom length at different angles ).

please be considered during calculations to be more conservative the moment and thrust load assumed to be as follows:

Axial load: 165000 pound Moment load : 3661285 ft.lbs Moment load due to side load 14444402 ft.lbs

These values are calculated based on the (2x Static load + Crane dead weight)*(Boom length at different angles ) .

SECTION 3

PEDESTAL CONE CALCULATION PER API -RP -2A

MAXIMUM MOMENT WITH CORESPONDINF THRUST

Crane Model : T80-62-82

Job Number:1221 /Basic Marine

Pedestal Gemometry

Cone Transition variables :

Inputing Pedestal Geometry :

“Yield Strength of Material , Fy”

“Modulus of Elasticity ,E”

“Outer Diameter of Pedestal at DO1”

“Outer Diameter of Pedestal at bottom, DO2”

“Pedestal Wall Thickness ,T”

“Effective length coefficient , K”

“Total Height of the Pedestal adapter”

Assigning the coresponding Variables :

Fy

((psi))

50000

E

((psi))

29000000

Do1

((in))

Do2

((in))

T

((in))

K

H

((in))

Importing Load ranges:

Assigning the corresponding Variables : MAX MOMENT CORRESPONDING AXIAL

OTMmax

(( ⋅ft lbf))

3661285

ALcor

((lbf))

168000

=OTMmax ⎛⎝ ⋅4.394 10

7 ⎞⎠ ⋅in lbf

≔OTMSIDE =⋅17332824 in lbf ⎛⎝ ⋅1.733 10 7 ⎞⎠ ⋅in lbf

ESM and Ratio Check :

Maximum (Do1) and Minimum (Do2) diamater of the cone is checked for Width-Thickness ratio :

≔ratio1 ―― Do1

T =ratio1 60

≔ratio2 ―― Do2

T =ratio2 66

≔Ratio =max ⎛⎝ ,ratio1 ratio2 ⎞⎠ 66

According to AISC 13th edition TABLE B4.1 case 15 :

≔λr =⋅0.11 ―― E

Fy 63.8

≔ESM ‖

if else

<Ratio λr ‖ ←word “Non -compact element”

‖ ←word “Check API-2A Procejure”

=ESM “Check API-2A Procejure”

According to API RP 2A for D/t ratios gereater than 60 , critical Local buckling shall be considered :

≔ESMapi ‖ if else

≤Ratio 60 ‖ ←word “No-Critical buckling”

‖ ←word “Critical buckling load should be checked”

=ESMapi “Critical buckling load should be checked”

Section Modulus and Slenderness Ratio Check :

Calculations of Radius of gyration (r) , slenderness ratio (Sr) , and Area section modulus (I) , Effective Area (A) :

It is coservative to use 60" diameter to calculate Section properties.

at D=60 in:

≔Di =−Do1 2 T 58 in

≔I =―――――― ⋅π ⎛⎝ −Do1

Di

4 ⎞⎠

⎛⎝ ⋅8.068 104 ⎞⎠ in4

≔A =―――――― ⋅π ⎛⎝ −Do1

Di

2 ⎞⎠

185.354 in2

≔r = I

A

20.863 in

Calculations of one-half of apex angle of the cone :

≔x =――――――――

−−Do2 2 T (( −Do1 2 T))

H

0.029 rad t ( ) 1 637 d

≔α =atan ((x)) 1.637 deg

≔l =――― H cos ((α))

105.043 in

≔Sr =――――

⋅K ――― H cos ((α)) r

10.07

AISC 13th edition sec E2 :

The memebers designed for compresion the slenderness ratio KL/r shall not exceed 200 :

≔E2Check ‖ if else

>Sr 200 ‖ ←word “Violation of AISC”

‖ ←word “Sr is accepted according to AISC”

=E2Check “Sr is accepted according to AISC”

Critical local buckling calculations per API RP_2A

Note Sec 3.2.2.b :When D/t ratio is greater than 60 and less than 300 , With wall thickness t>0.25 , both the elastic (Fxe) and inelastic (Fxc ) loacal buckling stress due to axial compresion should be determined .

1) Elastic local buckling stress : Fxe

Local buckling coeficient ≔Ce 0.3

≔Fxe =―――― ⋅⋅⋅2 Ce E T

Do2 ⎛⎝ ⋅2.636 10

5 ⎞⎠ psi

2) Inelastic local buckling stress , Fxc

≔Fxc =⋅Fy

−1.64 ⋅0.23

Do2 cos ((α)) T

⎛⎝ ⋅4.922 10 4 ⎞⎠ psi

Smaller of Fex and Fxe :

≔Fsml =min ⎛⎝ ,Fxc Fxe ⎞⎠ ⎛⎝ ⋅4.922 10

4 ⎞⎠ psi

Axial and Bending Stress in Major Axis

Axial stress :

≔fa =―― ALcor

A

906.374 psi

Bending Stress :

≔C =―― Do1

30 in

≔fby =―――― ⋅OTMmax C

I ⎛⎝ ⋅1.634 10

4 ⎞⎠ psi =fby ⎛⎝ ⋅1.634 10

4 ⎞⎠ psi

≔fbside =―――――

⋅OTMSIDE C

I ⎛⎝ ⋅6.445 10

3 ⎞⎠ psi

Allowable Axial Compresion API RP_2A Sec 3.2.2 :

Compression Calculation :

≔Fy ‖ if else

>Ratio 60 ‖ Fsml

‖ Fy

=Fy ⎛⎝ ⋅4.922 10 4 ⎞⎠ psi

≔Cc =

⋅⋅2 π

E

Fy

107.845 =Sr 10.07

API RP_2A Allowable Axial compresion Sec 3.2.2 :

≔Fa1 =―――――――

−1

Sr

⋅2 ((Cc))2

Fy

⋅3 Sr

⋅8 Cc

Sr

⋅8 Cc3

⎛⎝ ⋅2.88 10 4 ⎞⎠ psi For Sr<Cc

≔Fa2 =―――― ⋅⋅12 π

E

⋅23 Sr

⎛⎝ ⋅1.473 10 6 ⎞⎠ psi For Sr>=Cc

≔Fa if else

<Sr Cc ‖ ←Fa Fa1

‖ ←Fa Fa2

=Fa ⎛⎝ ⋅2.88 10

4 ⎞⎠ psi

Allowable Bending API RP_2A Sec 3.2.2 :

API RP-2A Allowable Bending Sec 3.2.3 :

≔Fb1 =⋅0.75 Fy ⎛⎝ ⋅3.691 10 4 ⎞⎠ psi ≤――

Do

T

⋅1500 ksi

Fy

≔Fb2 =⋅

−0.84 1.74 ―――― (( ⋅Fy Do1))

⋅E T

Fy ⎛⎝ ⋅3.262 10 4 ⎞⎠ psi ≤<―――

⋅1500 ksi

Fy Do

T

⋅3000 ksi

Fy

≔Fb3 =⋅

−0.72 0.58 ―――― (( ⋅Fy Do1))

⋅E T

Fy ⎛⎝ ⋅3.253 10 4 ⎞⎠ psi ≤≤―――

⋅3000 ksi

Fy Do

T

≔Fb if else if else if

Do1

T

⋅1500 ksi

Fy ‖ ←Fb Fb1

⋅1500 ksi

Fy Do1

T

⋅3000 ksi

Fy ‖ ←Fb Fb2

⋅3000 ksi

Fy Do1

T

‖ ←Fb Fb3 return Fb

=Fb ⎛⎝ ⋅3.262 10

4 ⎞⎠ psi

Unity Check API RP_2A Sec 3.3.1 ombined Axial Compresion and Bending:

≔Formula if else fa

Fa

0.15

‖ “Use 3.3.1-3 formula”

‖ “See section 3.3.1”

=Formula “Use 3.3.1-3 formula”

Bending due to side loads ≔fbx =fbside ⎛⎝ ⋅6.445 10

3 ⎞⎠ psi

=fbside ⎛⎝ ⋅6.445 10

3 ⎞⎠ psi

≔Unity =+― fa

Fa fbx cos ((α))

2 ⎛ fby cos ((α))

Fb

0.57 Eq:3.3.1-3

≔UnityCH ‖ if else

<Unity 1 ‖ “Unity check passed”

‖ “Unity check failed”

=UnityCH “Unity check passed”

Stress Limitation at Cone-Cylinder Junction :

Longitudianal stress:

≔fb = fbx cos ((α))

2 ⎛ fby cos ((α))

⎛⎝ ⋅1.757 10 4 ⎞⎠ psi

≔f'b =――――――― ⋅⋅0.6 T ‾‾‾‾‾‾‾‾‾‾⋅Do1 (( +T T))

T

⎛⎝ +fa fb ⎞⎠ ((tan ((α)))) ⎛⎝ ⋅3.47 10

3 ⎞⎠ psi

=+fa fb ⎛⎝ ⋅1.848 10

4 ⎞⎠ psi

API 2A SEC 3.4.1C Tensile strenght of material :

=++fa fb f'b ⎛⎝ ⋅2.195 10

4 ⎞⎠ psi

≔Ft =65 ksi ⎛⎝ ⋅6.5 10 4 ⎞⎠ psi

Limiting the angle according to table :

≔Checklimit ‖ if else

<⎛⎝ +fa fb ⎞⎠ ⋅0.6 Fy

‖ “normal condition”

‖ “Revise dimension”

=Checklimit “normal condition”

API 2A SEC 3.4.1.C, SEC :Recomended Stress concentration factor

≔SCF =+1 ―――

f'b

+fa fb

1.188

≔SCF =+1 ⋅0.6

⋅2 ――

Do1

T tan ((α)) 1.188

Results :

Axial Load:

=fa 906.374 psi

Bending Moments:

=fbx ⎛⎝ ⋅6.445 10

3 ⎞⎠ psi

=fby ⎛⎝ ⋅1.634 10

4 ⎞⎠ psi

=fb ⎛⎝ ⋅1.757 10

4 ⎞⎠ psi

Allowable bending:

=Fb ⎛⎝ ⋅3.262 10

4 ⎞⎠ psi

Allowable AXIAL:

=Fa ⎛⎝ ⋅2.88 10

4 ⎞⎠ psi

=ESM “Check API-2A Procejure”

=ESMapi “Critical buckling load should be checked”

=Unity 0.57

Sum of Axial and bending:

=+fa fb ⎛⎝ ⋅1.848 10

4 ⎞⎠ psi =Checklimit “normal condition”

Stress coccentration factor:

=SCF 1.188

SECTION 4

PEDESTAL FEA SIMULATION RESULTS

PEDESTAL FEA ANALASIS

Job1221 BASIC MARINE

Applied load :(moment from side load is also applied)

Axial load:165000 lbf Moment load Around X : -43940000 in.lbf Moment load due to side load around Z : - 17332824 in.lbf

Von-mises stress:

Back view:

Job1221 BASIC MARINE

Stress on manway to pedestal junction when 100% penetration applied.

Job1221 BASIC MARINE

Section 2 : Displacement (in)

Job1221 BASIC MARINE

STRESS RANGE:

DISPLACEMENT RANGE:

Summary

Your design is safe based on the parameters entered.

This data was generated by Engineering department on 3/28/2013 at 16:07:40

This data was checked by Darius Shad on 3/28/2013

Comments - Analyisis is based on API 2C and API 2A

Analysis options

The following analysis options were chosen

·The - Signed VonMises - analysis method was used ·Analysis was performed on the highest 100 percent of stresses ·Stresses below 0psi were not considered in the fatigue calculations ·Nodal stress averaging was performed. This may increase the predicted Life

All Parts were used in the analysis

Material

A Steel material was analysed.

Psi Stress units selected

Material = Material A572 Modulus of Elasticity = 2.9E+07 Ultimate Tensile Strength = 650000 Endurance Limit = 30000 Number of cycles at Endurance = 1E+07

Stress-Life definition

Method

The Stress Based analysis method was chosen.

Stress based analysis is a direct solution and is generally quicker than Strain based analysis.

Advantages afarah Typewritten Text Fatigue Report on PedestaL afarah Typewritten Text afarah Typewritten Text

·Quicker to perform than Strain based methods.

·Disadvantages ·Not applicable for low cycle analysis (less than 10000 cycles to failure) ·Pessimistic. May predict failure when no failure occurs in reality.

·High cycle fatigue only (Greater than 10000 cycles) ·More input may be required

Modifiers

Stress Concentration Factor Kf =1.18 Reliability = 1 Miscellaneous = 0.65 Surface Finish = 1.000

Manufacturing method chosen =

Overall factor (Kf) = 0.650

Loading

There are 1 load cases in the Linear Static model.

Only the Load Cases/Curves defined below were used in the fatigue analysis.

The loading history defined, acts as a multiplier to your Linear Static Stress results.

Load curve 1

The above loading was then repeated 1000000 times, in the analysis.

Results

Desired number of cycles before failure = 1000000 Predicted Number of cycles to failure = 7.692307E+30