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Development of an Acoustic Emission Test Platform with a Biaxial Stress Loading System. Progress Report for the Period August 22, 2002 – March 31, 2003. Joseph Oagaro, Shreekanth Mandayam, John L. Schmalzel and Ronnie K. Miller. Electrical & Computer Engineering 201 Mullica Hill Road
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Development of an Acoustic Emission Test Platform with a Biaxial Stress Loading System Progress Report for the Period August 22, 2002 – March 31, 2003 Joseph Oagaro, Shreekanth Mandayam, John L. Schmalzel and Ronnie K. Miller Electrical & Computer Engineering 201 Mullica Hill Road Glassboro, NJ 08028 (856) 256-5333 http://engineering.rowan.edu/ PERF 95-11 STEERING COMMITTEE MEETING Sheraton Seattle Hotel & Towers, Seattle, Washington April 16, 2003
Presentation Outline • Project Objectives • Personnel • Test Specimens • AE Training and Quality Assurance • AE Test Platforms (Design, Development and Results) • Version 1 • Version 2 • Version 3 • Summary and Future Work
Project Objectives • Design and develop test-platforms for performing Acoustic Emission (AE) measurements on defective pipe segments under bi-axial stress conditions • Develop empirical relations between stress and AE signal parameters
Major Tasks • Specimen fabrication • Set-up for 2-D Tensile Testing • Instrumentation (AE and control) and data acquisition set-up • AE testing: collaboration with Physical Acoustics Corporation • Signal analysis
Data Acquisition Signal Conditioning Display/ User Interface Conceptual Design: Test Platform AE Sensors Specimen Load Cell Simulated Defect Double Acting Hydraulic Ram
Test Platform Design Criteria • Design Challenges • Rigid Frame • Biaxial Loading of test specimen • 30,000 psi (45,000 lbs) 1st Dimension • 15,000 psi (22,500 lbs) 2nd Dimension • Short manufacturing time • Low cost
Project Personnel • Rowan • Dr. Shreekanth Mandayam (PI), Dr. John Schmalzel (Co-PI), Joe Oagaro (Senior ECE), Dan Edwards (Senior ME), John Ludes (Junior ECE), Terry Lott (Junior ME) • PAC • Dr. Ronnie K. Miller
Specimen Fabrication • Provided by Shell • 0.5” Thick SA-516 grade 70 Steel Coupons • Simulated Cracks of varying depths • .08”, .16”, and .32” deep • Two sets of 3 specimens each
In-House Specimen Fabrication • ASTM 836 steel specimens • Saw-cut defects (80% deep, 2.5” long) Rowan Water Jet Machining Center
Collaboration with PAC • Rowan personnel were trained on AE system at PAC on August 22, 2002 • 4-Channel AE system was delivered to Rowan on September 26, 2002 • Rowan personnel were trained on system by PAC • Project meeting on January 30, 2003 for reviewing test results; design and test modifications suggested
AE Test Platforms • Version 1 • Prototype Design • 13.5ksi (20,000 lbs) max load • Version 2 • Clamping Bracket Modification • 20,000ksi (30,000 lbs) max load • Version 3 • Hydraulic Rams • Full Desired load of 30ksi (45,000 lbs)
Frame Load Transducer Specimen Loading Screws Specimen Clamping Bracket AE Test Platform: Version 1
FEM Analysis COSMOSWorks FEM analysis of clamping block
AE Test Station Construction: Version 1 1/24/2003
Testing Parameters • Specimen was preloaded to: • Axis 1: 10,000 lbs • Axis 2: 20,000 lbs • AE sensors activated and test run for approximately 30 minutes • Crack Depth 60%, Length 2.5”
Design Limitations: Version 1 • Clamping method caused deformation of specimen producing spurious AE data. • Location View shows AE Hit concentration in proximity of clamping brackets • Connection from load cell to specimen fixed, causing bending moment and non-uniform loading of specimen • Inability to reach desired load
Frame Load Transducer Specimen Loading Screws Specimen Clamping Bracket AE Test Platform: Version 2 • New Clamping Brackets • Pinned connections for ensure uniform loading • Max load of 30,000 lbs
Testing Parameters • AE sensors active throughout loading of specimen • Specimen loaded in steps of 2000 lbs up to: • Axis 1: 30,000 lbs • Axis 2: 15,000 lbs • Signal processing to remove spurious data during loading of test platform
AE Location: Version 2 COSMOSWorks FEM Model
Why Version 3? • Hydraulic design • Allows for increasing max load to 30 ksi • Controlled loading environment • New clamping bracket • Single pin piece – minimizes noise
Frame Load Transducer Specimen Hydraulic Cylinders Specimen Clamping Bracket AE Test Platform: Version 3
Summary of Progress • Rowan personnel have been trained in AE testing techniques by PAC • Two versions of the biaxial loading test platform constructed – fabrication of third and final version underway • AE tests conducted on test specimens fabricated in-house; specimens provided by Shell will be tested on Version 3 • AE signatures obtained for 1-D and 2-D loading of the test specimens indicate appreciable differences, demonstrating proof-of-concept of the technique • Continuous interaction with PAC for quality assurance.
Future Plans • Develop Version 3 of the test platform withhydraulic loading • Conduct tests on specimens provided by Shell • Parameterize AE signature differences between uni- and bi-axial loading of test specimens • Generate calibration curves and empirical relationships quantifying 1-D and 2-D stress effects • Generate final report summarizing all findings • Provide recommendations for design of a pressure vessel test platform