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