failure analysis
DESCRIPTION
Failure AnalysisTRANSCRIPT
07/06/2015
1
Group Project
Engineering Failure Analysis
Dr. A. AndriyanaKXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Objectives
Dr. A. Andriyana
� Investigate the possible root causes of failure in river
crossing gas pipe
� Provide recommendations so that similar failure can
be prevented in the future
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
07/06/2015
2
Field Survey and Inspection
Dr. A. AndriyanaKXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Field Survey and Inspection
Dr. A. Andriyana
Field Data Quantity
Pipe outer diameter 6 in
Initial pipe thickness 0.28 in
Temperature 30 °C
Internal pressure 16-40 kg/cm2
Flow rate 5-18 MMSCFD
Fluid density 0.675 kg/m3
Service loading condition
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
07/06/2015
3
Field Survey and Inspection
Dr. A. Andriyana
Field Data Type or Quantity
Type of material Steel
Yield strength (σy) 290 MPa
Tensile strength (σu) 420 MPa
Fracture toughness (KIC) 70 MPa·m1/2
Fatigue limit 85 MPa
Pipe materials
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Methodology
Dr. A. AndriyanaKXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Stress analysis using FEA
(with and withoutcrack)
Fabrication method
Microstructuralanalysis
07/06/2015
4
Field Survey and Inspection
Dr. A. Andriyana
Failure location
Fracture
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Field Survey and Inspection
Dr. A. Andriyana
Failure location
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
07/06/2015
5
Finite Element Analysis
Dr. A. Andriyana
Data Remark
Software used NASTRAN and AUTOPIPE
Pipe initial thickness 0.28 in
% of corroded thickness ≈ 29%
Effective thickness 0.2 in
Type of loadInternal pressure and
centrifugal thrust
Note:
Computation is performed without considering defects (crack)
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Finite Element Analysis
Dr. A. Andriyana
X
Y
Z
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23456234562345623456234562345623456234562345623456
23456234562345623456234562345623456234562345623456
2345623456234562345623456234562345623456
2345623456234562345623456234562345623456
2345623456234562345623456234562345623456 2345623456
23456234562345623456
2345623456
23456234562345623456
2345623456
2345623456
2345623456
2345623456
23456234562345623456
23456234562345623456
2345623456 2345623456
2345623456
2345623456
2345623456
2345623456
2345623456
2345623456
23456234562345623456 2345623456
23456234562345623456
2345623456
2345623456
2345623456
234562345623456234562345623456
23456234562345623456
2345623456234562345623456234562345623456
2345623456
23456234562345623456234562345623456234562345623456234562345623456234562345623456
234562345623456234562345623456
234562345623456234562345623456 23456234562345623456
23456234562345623456
234562345623456234562345623456234562345623456234562345623456234562345623456234562345623456234562345623456234562345623456 23456234562345623456234562345623456234562345623456
V1
L1
C1
Finite element model around pipe bend
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
07/06/2015
6
Finite Element Analysis
Dr. A. Andriyana
Modeling of centrifugal thrust due to fluid flow
X
Y
Z
144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03
144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03 144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03
144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03144.03
V1
L2
C1
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Finite Element Analysis: Static Loading
Dr. A. Andriyana
Stress field due to internal pressure and centrifugal thrust
X
Y
Z
61641400.
58496945.
55352490.
52208035.
49063580.
45919125.
42774670.
39630215.
36485761.
33341306.
30196851.
27052396.
23907941.
20763486.
17619031.
14474576.
11330121.
V1
L2
C1
Output Set: MSC/NASTRAN Case 1
Deformed(0.00138): Total Translation
Contour: Plate Bot VonMises Stress
X
Y
Z
61641400.
58496945.
55352490.
52208035.
49063580.
45919125.
42774670.
39630215.
36485761.
33341306.
30196851.
27052396.
23907941.
20763486.
17619031.
14474576.
11330121.
V1
L2
C1
Output Set: MSC/NASTRAN Case 1
Contour: Plate Bot VonMises Stress
X
Y
Z
61641400.
58496945.
55352490.
52208035.
49063580.
45919125.
42774670.
39630215.
36485761.
33341306.
30196851.
27052396.
23907941.
20763486.
17619031.
14474576.
11330121.
V1
L2
C1
Output Set: MSC/NASTRAN Case 1
Deformed(0.00138): Total Translation
Contour: Plate Bot VonMises Stress
X
Y
Z
61641400.
58496945.
55352490.
52208035.
49063580.
45919125.
42774670.
39630215.
36485761.
33341306.
30196851.
27052396.
23907941.
20763486.
17619031.
14474576.
11330121.
V1
L2
C1
Output Set: MSC/NASTRAN Case 1
Contour: Plate Bot VonMises Stress
Thickness
(in)
σmax
(MPa)
0.28 53.31
0.20 62.73
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
07/06/2015
7
Finite Element Analysis: Static Loading
Dr. A. Andriyana
Stress due to internal pressure and centrifugal thrust
Location of highest
stress
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Mechanical and Microstructure Analysis
Dr. A. Andriyana
A (straight pipe)B (pipe bend)
WeldFracture
1 2
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
07/06/2015
8
Microstructure Analysis
Dr. A. Andriyana
Location of the samples 1
(200x)
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Microstructure Analysis
Dr. A. Andriyana
Location of the samples 1
After annealing
(200x) (200x)
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
07/06/2015
9
Microstructure Analysis
Dr. A. Andriyana
Location of the samples 2
(200x)(240x)
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Mechanical Testing and Analysis
Dr. A. Andriyana
Sample location Yield strength Fracture toughness
750 MPa 40 MPa·m1/2
290 MPa 70 MPa·m1/22
1
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
07/06/2015
10
Stress analysis of crack
Dr. A. Andriyana
LocationInitial crack length
(a)
Critical crack length
(ac)
Stress intensity
factor (KI)
2.95 μm 4.00 mm 55 MPa·m1/2
2.95 μm 6.00 mm 45 MPa·m1/22
1
Note:
Computation is performed by considering internal pressure only
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis
Manufacturing of Pipe Bend: Ram Pipe Bending
Dr. A. Andriyana
Pressure die
PipeBending die
Ram
� The pipe is restrained at two points using pressure die and then heated
� The ram advances by a mechanical force in the central axis and deforms the pipe
to the contours of the die
� After bending occurs, the heated area is cooled by immersing it in water
KXGB 6301 / KXGM 6310 - Fatigue, Failure and Failure Analysis