吊耳计算式

CONTENTS

1GENERAL (3)

2REFERENCE DOCUMENTS (3)

3DESIGN CONDITION (4)

3.1Design Loads (4)

3.2Dimension And Materials (4)

4STRENGTH CHECK FOR TYPE I PADEYE (6)

4.1Bearing stress (Eye portion) (6)

4.2Shear stress (Eye portion) (6)

4.3Welding Check for Cheek Plate (6)

4.4Compression and Bending Stress of Padeye Plate (6)

4.5Shear Stress of Padeye Plate (8)

4.6Connection between Padeye Main Plate and Column (8)

1 GENERAL

The LD32-2 MOPA Platform is to be located in Bohai Bay, P.R. China. Following transportation to site, MOPA deck will be installed by lifting from the transportation barge.

A total of four lift points will be used for installation.

The padeye design and stress check for LD32-2 MOPA deck is performed according to API RP 2A and AISC WSD codes. The lifting arrangement and details are shown in drawings LD32-2-DWG-MOPA-ST-1006. Calculated padeye reactions and lift analysis is detailed in Report LD32-2-RPT-MOPA-ST-1006.

The results of this calculation indicate that the padeyes are adequate for lifting condition.

2 REFERENCE DOCUMENTS

1) API RP 2A Recommended Practice for Planning, Designing, and Constructing

Fixed Offshore Platforms – 21st Edition W.S.D.

2) AISC Specification for Structural Steel Buildings – Allowable Stress and Plastic

Design 9th Edition

3) AWS D1.1 Structural Welding Code – Steel

4) LD32-2-SPC-GEN-ST-0001 Specification for Structural Design

3 DESIGN CONDITION

3.1 Design Loads

There is only one type of lifting padeye in calculation. Maximum force in sling wire: P= 2490.02 kN, use 2500.00 kN. The maximum force includes dynamic load factor of 2.0.

The angle from horizontal of the sling is considered as 60 degrees.

Loads acting on padeye:

P H = 2500.00 X cos (60︒) = 1250.00 kN

P V = 2500.00 X sin (60︒) = 2165.06 kN ,use 2200.00 kN.

3.2 Dimension And Materials

Padeye detail:

Pin diameter: 108 mm

Hole diameter: 112 mm

Padeye main plate material: GB 712-2000 E36-Z35. Fy=35.5 kN/cm2

Other plate material: GB 712-2000 D36. Fy=35.5 kN/cm2

For drawing of Lifting padeye, see next page.

4 STRENGTH CHECK FOR TYPE I PADEYE

4.1 Bearing stress (Eye portion)

f p = 2500.00 / (10.8 x 11.4) = 20.31 kN/cm2 < 31.95 kN/cm2

Allowable bearing stress: F p

F p = 0.9Fy = 0.9 x 35.5 = 31.95 kN/cm2

4.2 Shear stress (Eye portion)

A s=2 x (35 - 11.2/2) x 5.0 + 4 x (30 - 11.2/2) x 3.2 = 606.32 cm2

f v = 2500.00 / 606.32 = 4.12 kN/cm2 < 14.2 kN/cm2

Allowable shear stress: Fv

F v = 0.4F y = 0.4 x 35.5 = 14.2 kN/cm2

4.3 Welding Check for Cheek Plate

Required weld area for cheek plate: A w1

A w1 = Pt/F w T = 2500.00 x 3.2 / (14.2 x 11.4) = 49.42 cm2

Required Weld Size: S1= 20.5 x 49.42 / 179.43 = 0.39 cm

Use 25 mm fillet weld.

4.4 Compression and Bending Stress of Padeye Plate

A =130.8 x 5.0 + (90.0-5.0) x 3.2 x 2 = 1198.0 cm2

In plane bending inertia moment I yy = 2381317.73 cm4

Out of plane bending inertia moment I zz = 390095.83 cm4

In plane bending

M y = 1250.00 x 32 = 40000.00 kN-cm

Out of plane bending

M z = 2500.00 x (32 + 11.2/2 + 30) x 0.05 = 8450.00 kN-cm