S. Mandayam/ECE Dept./Rowan University Development of an Acoustic Emission Test Platform with a Biaxial Stress Loading System Joseph Oagaro, Shreekanth.

S. Mandayam/ECE Dept./Rowan University

Development of an Acoustic Development of an Acoustic Emission Test Platform with a Emission Test Platform with a Biaxial Stress Loading System Biaxial Stress Loading System

Joseph Oagaro, Shreekanth Mandayam, John L. Schmalzel and Ronnie K. Miller

Electrical & Computer Engineering201 Mullica Hill RoadGlassboro, NJ 08028

(856) 256-5333http://engineering.rowan.edu/

Progress Report for the Period June 1 – August 31, 2003

PERF 95-11 STEERING COMMITTEE MEETINGAdams Mark Hotel, Denver, Colorado

September 17, 2003

S. Mandayam/ECE Dept./Rowan University

Project ObjectivesProject 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

S. Mandayam/ECE Dept./Rowan University

Test Platform Design CriteriaTest Platform Design Criteria

• Design Challenges• Rigid Frame

• Biaxial Loading of test specimen

• 30,000 psi (45,000 lbs) along Axis 1

• 15,000 psi (22,500 lbs) along Axis 2• Low cost

S. Mandayam/ECE Dept./Rowan University

Specimen FabricationSpecimen Fabrication• Provided by Shell Oil Co.• 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

• Uniaxial and Biaxial Loading• simulates axial and hoop

stresses of a pressurized pipeline

• Duplicate specimens machined in-house with saw cut defects

S. Mandayam/ECE Dept./Rowan University

Construction History:Construction History: Version 1 Version 2 Version 1 Version 2

• Clamping method caused deformation of specimen producing spurious AE data

• Fixed connection caused bending moments and non-uniform loading of specimen

• Inability to reach desired load - 13.5ksi (20,000 lbs) max load

• Additional connections for new clamping brackets create extraneous noise producing false AE data

• Increased loading capability but still not full desired load – 20ksi (30,000 lbs) max load

S. Mandayam/ECE Dept./Rowan University

AE Test Platform Design: AE Test Platform Design: Version 3Version 3

Frame

Load Transducer

Specimen

HydraulicCylinders Specimen Clamping

Bracket

S. Mandayam/ECE Dept./Rowan University

Why Version 3?Why Version 3?• Hydraulic design

• Allows for increasing max load to 30 ksi (45,000 lbs) • Controlled loading environment• Negligible noise effects with hydraulic loading

• New clamping brackets• Single bracket piece – minimizes noise• Designed to withstand forces exceeding maximum

loading specs• 1” Pinned connections to specimens

• Allows for movement of specimen to linearize loading• Prevents deformation of specimen at connection

S. Mandayam/ECE Dept./Rowan University

AE Test Platform: Version 3AE Test Platform: Version 3

S. Mandayam/ECE Dept./Rowan University

Summary of ProgressSummary of Progress

• Additional test specimens identical (steel grade and dimensions) to those provided by Shell Oil have been fabricated

• Version 3 of the AE test platform with hydraulic loading has been built

• The platform has been tested to provided desired load of 45,000 lbs along Axis 1 and 22,500 lbs along Axis 2

• Initial test indicate repeatable loading with minimized extraneous noise

S. Mandayam/ECE Dept./Rowan University

Future PlansFuture Plans• Work with PAC personnel to conduct tests on both in-

house and Shell specimens with Version 3 test platform

• 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 the design of a pressure vessel test platform