Engineering Study for Barge Lifting Weight on Crane Barge Overload Test Bernardo Xavier Guilherme Leal Thayanna Araujo

Rio de Janeiro – 03/12/2012

Typical crane overload test description;

Motivation

Load curve estimate for overload test procedures;

Motivation

Simple engineering for overload test weight determination; Overload test engineering becomes tricky when lift weight increases;

Motivation

- HARD TO CALIBRATE - DINAMIC BEHAVIOUR

Solution? - Modify the concept of the test weight. Engineering? - Loading conditions and draft marks definition; - Evaluation of the structural integrity of the test barge and lifting

padeyes;

Motivation

TEST BARGE

- Engineering study for crane overload test for SWL 2050 tons maximum load curve; - Test weight shall be a calibrated ballasted deck barge; Crane barge main particulars:

Objectives

Length over all 110 m Molded breadth 39 m

Molded depth 7 m

Main hook capacity 2050 ton

Test barge main particulars

Length over all 59.90 m Molded breadth 21.36 m

Molded depth 4.2 m Deadweight 3000 ton

The maximum overload weight shall be 2255 tons, which considers a 10% overload factor of a maximum safe working load of 2050 tons. A total of five loading conditions shall be tested: The test barge was carefully selected for the lifting weight purpose in which shall be fully lifted out of the water in order to provide a accurate and realistic results of the overload test as well as the calibration of the load cells for the crane barge;

Design premisses

Load Condition Total (ton) 1 720.72 2 1186.15 3 1596.45 4 1782.02 5 2255.02

For structural integrity analysis, DNV SESAM software package was used: - GeniE V5.3-10: Local and global structural analysis; - SESTRA 8.4-01: Linear Structural analysis - Submod V6.1-05: Submodeling coupling from global to local FE model; - Xtract 3.0-00: Post-process of the structural results;

Design premisses

Structural evaluation of test barge (DEC Criteria);

Design premisses

Typical spreader bar scheme;

Lifting configuration

Typical 4 lifting point design;

Lifting points

Padeye design for SWL 650 tons based on “N2683 – Estruturas Oceânicas – Olhal de içamento – Dimensionamento”.

Lifting Padeyes Design

Special consideration for weld shear stress stiffness and load transfer to the test barge;

Engineering Study for Barge Lifting Weight on Crane Barge Overload Test

O QUE ?

COMO ?

Global FEM model

Engineering Study for Barge Lifting Weight on Crane Barge Overload Test

O QUE ?

COMO ?

Global FEM model mesh size = 0.5m;

Engineering Study for Barge Lifting Weight on Crane Barge Overload Test

Typical ballasted load condition;

Engineering Study for Barge Lifting Weight on Crane Barge Overload Test

Local FEM model

Engineering Study for Barge Lifting Weight on Crane Barge Overload Test

Local FEM model mesh size = 0.05m;

Engineering Study for Barge Lifting Weight on Crane Barge Overload Test Von mises stress results (Max allowable = 225 MPa) (Max load case);

Engineering Study for Barge Lifting Weight on Crane Barge Overload Test

Analytical hull girder bending check;

Bending moments, normal stresses and shear stress along the hull.

Engineering Study for Barge Lifting Weight on Crane Barge Overload Test

-2,00E+05-1,50E+05-1,00E+05-5,00E+040,00E+005,00E+041,00E+051,50E+052,00E+05

0,5 4

7,5 11

14,5 18

21,5 25

28,5 32

35,5 39

42,5 46

49,5 53

56,5

59,9

Bend

ing

Mom

ent (

Pa)

Length (m)

Bending moments x length

-3,00E+07

-2,00E+07

-1,00E+07

0,00E+00

1,00E+07

2,00E+07

3,00E+07

0,5

3,5

6,5

9,5

12,5

15,5

18,5

21,5

24,5

27,5

30,5

33,5

36,5

39,5

42,5

45,5

48,5

51,5

54,5

57,5

Nor

mal

Str

ess

(Pa)

Length (m)

Normal Stresses x length

-4,00E+06

-3,00E+06

-2,00E+06

-1,00E+06

0,00E+00

1,00E+06

2,00E+06

3,00E+06

0,5 4

7,5 11

14,5 18

21,5 25

28,5 32

35,5 39

42,5 46

49,5 53

56,5

59,9

Shea

r Str

ess (

Pa)

Length (m)

Shear Stresses x length

RESULTS ARE IN ACCORDANCE WITH FEM ANALYSIS

Advantages of using SESAM software

• User friendly interface for complex geometry modeling;

• Easy to model structures which optimizes precious time on overall

project schedule;

• Great result analysis tools for stress plots;

SESAM software package was highly suitable for the proposed study in which demonstrated that the test barge has adequate structural integrity for the proposed loading conditions; Crane barge overload actual test is scheduled for January 2013;

Conclusion