reinforcement of girth welds using composite materials ... weld testing... · reinforcement of...
TRANSCRIPT
Reinforcement of Girth Welds Using Composite Materials (PRCI MATR-3-7)Prepared for Composite Manufacturers / PRCI ● January 18, 2012Presentation by Dr. Chris Alexander, P.E. and Julian Bedoya, P.E.
Preliminary Data Presentation
2
Program Overview• Focus is to evaluate the ability of composite
materials to reinforce girth welds subject to axial loading
• Program based on previous 2006 MMS study and recent wrinkle bend studies
• Full-scale test program involving: Vintage welds (intentional defects) Repair using composite materials (designed per ASME
PCC-2 as applicable) Test loads: Pressure (36% SMYS, constant), axial
tension, and bending• Five (5) composite systems tested to date
3
Current Status• Pipe material: 12.75-inch x 0.188-inch, Grade X42• Sample preparation Defective girth welds fabricated (lack of penetration) Material testing (Charpy, mechanical, and chemistry) Installation surface sandblasted (NACE 2) Strain gages installed
• All manufacturer installations completed• Testing was completed by end of December• Data being post-processed• Report(s) to be completed by end of February
4
Sample Details• Unrepaired One (1) unrepaired pressure/tension sample One (1) unrepaired pressure/tension/bending sample
• Repaired Six (6) reinforced pressure/tension samples Six (6) reinforced pressure/tension samples with
reduced bonding area via Mylar packing tape (to simulate local disbondment)
Six (6) reinforced pressure/tension/bending samples For the manufacturer, the repaired geometry for all
samples must be the same (3-ft max length)
5
96-inches
Configuration for 8-ft Tension Samples
Girth weld
Key Points1. Surface preparation2. Length of reinforcement3. Consistent girth weld fabrication4. Instrumentation: strain gages beneath and on top of the composite5. Generate load deflection curves for each manufacturer6. Identify products by NAME7. Assessment of repair relative to ASME PCC-2 / ISO 24817
Strain gage locations on pipe
Composite repair location zoneACME ThreadedEnd Caps
Strain gage locations on repair
SG: ½”, 2”, & 6” from toe of GW
Drawing not to Scale
6
22-ft
Configuration for 22-ft Bend Samples
Girth weld
Key Points1. Surface preparation2. Length of reinforcement3. Consistent girth weld fabrication4. Instrumentation: strain gages beneath and on top of the composite5. Generate load deflection curves for each manufacturer6. Identify products by NAME7. Assessment of repair relative to ASME PCC-2 / ISO 24817
Strain gage locations on pipe
Composite repair location zone
Strain gage locations on repair
SG: ½”, 2”, & 6” from toe of GW
0 degrees
90 degrees
180 degrees
Drawing not to Scale
7
Test Results (1/4)• Tension Test Data for unrepaired (UR) sample provided Data for five (5) repaired samples
• Bending test Data for unrepaired (UR) sample provided Data for five (5) repaired samples Additional interpretation needed of this data as it is
not as clear as the tension test results (SES expected this to be the case)
8
Test Results - Tension (2/4)
Note: 1,000 mils equals 1.0 inch
9
Test Results - Tension (3/4)
Samples with NO tape (NO simulated disbonding)
NOTE: Colors changed from previous slide for clarity
10
Test Results - Bending (4/4)
11
Summary of Tension Results(Maximum values prior to loss of load)
• Displacement Unrepaired 0.29 inches Product C 7.50 inches Product E 2.50 inches Product B 0.95 inches Product A 0.87 inches Product D 0.51 inches
• Tension load Unrepaired 238.2 kips Product C 445.1 kips Product E 427.1 kips Product B 383.1 kips Product A 386.6 kips Product D 378.5 kips
12
Preliminary Observations• Presence of tape reduces overall load capacity,
although reduction not proportional to area of disbonding
• Ranking of performance independent of bonding (i.e. the better performing products also did well when considering the presence of disbonding)
• Repair systems seemed to perform more consistently across the board with the bend test, with gross deformation occurring outside of the repair being typical
• Product C actually caused failure to occur outside of the repair near end cap