PITA Fiscal Year 2011 Projects

Application Of Phased Array Ultrasonic Testing For Steel Bridge Inspection

Lead University: Lehigh University
PI: Sougata Roy, Department of Civil and Environmental Engineering
Co-PI(s): Eric Kaufmann, Department of Civil and Environmental Engineering
PA Industry: High Steel Structures Inc and Olympus NDT

The existing AASHTO/AWS D1.5: Bridge Welding Code allows only Radiographic Testing (RT) and Ultrasonic Testing (UT) for nondestructive evaluation of groove welds. In addition to being non-hazardous and portable, UT is quicker requiring less effort and is therefore preferred by fabricators. Most bridge owners, however, require RT for quality control of groove welds, as it produces a permanent radiograph of each inspection contrary to UT. This incurs additional cost to fabrication of steel bridges. In recent years, Phased Array Ultrasonic Testing (PAUT) has emerged as a technological advancement to conventional UT, which in addition to increased accuracy in detection of critical defects has the ability to provide a permanent record of inspection and therefore can eliminate the primary reservation in replacing RT with UT. Despite the advantages and promises, however, PAUT has not been widely used in steel bridge fabrication, primarily due to the lack of specification guidelines applicable to the bridge industry. A collaborative research project among three Pennsylvania entities — Lehigh University, High Steel Structures Inc., and Olympus NDT — is being proposed with the objective of developing a framework for consistent application of PAUT for inspection of groove weld splices in steel bridge fabrication. The research will compare and correlate findings of PAUT against inspections by RT and UT in both small scale controlled specimens and full scale fabricated structures, and will develop an outline of acceptance criteria by tolerable flaw size analyses. The outcome is expected to provide the foundation for developing AASHTO/AWS specifications for using PAUT as a NDT method for steel bridge inspection both in fabrication and in service. The research will have a positive impact on Pennsylvania’s economic growth in terms of creating new jobs, increasing revenue, generating investment for further technology development, and retaining quality educated work force in the state.