Session: 15-01-01: ASME International Undergraduate Research and Design Exposition

Paper Number: 151427

151427 - Fast and Efficient Welding Inspection of Structural Steel Using Adaptive Phased Array Ultrasonic Ndt 

Abstract:

Welding is indispensable in structural steel members due to its ability to create strong, durable, and versatile connections essential for constructing safe, efficient, and resilient infrastructure. Welded parts must be inspected to ensure they meet required quality and integrity standards. Quality assurance measures such as nondestructive testing (NDT) can be employed to verify the integrity of welds, providing confidence in the structural integrity of steel members. A range of NDT techniques may be used for welding inspection which depends on several factors including geometry and configuration of the joints, material, thickness of the welded parts, and inspection environment. Among the variety of NDT methods, configurations of ultrasonic testing (UT) are identified as efficient techniques of inspection for welding. Despite the effectiveness of the traditional UT techniques, the accuracy and repeatability of the tests can be significantly improved via advanced phased array technology. In this study, phased array UT (PAUT) is used to evaluate the quality of the welding in steel samples that were fabricated in various welding processing conditions. Potential flaws have been identified and verified by material characterization procedures. Results show that the PAUT can provide localized quality information of the weld and correlate to the mechanical properties (e.g., strength) of the part in the welding region.

Introduction:

Nondestructive ultrasonic testing (UT) with a single-element transducer is a powerful technique for the inspection and testing of flaws and defects in materials. However, the information that can be obtained from UT depends on many factors such as the frequency of the ultrasonic wave, wave mode, and its characteristics, material properties, and post-processing methodology. Meaning that depending on the direction of the wave path, some portion of a welded area will not be covered, and defects might not be detected. For a civil infrastructure to be in a safe and adequate shape of operation, it is not only required that the potential defects and anomalies be detected but also their characteristics must be identified. Defect characteristics such as size, shape, and location are critical for quality decision-making. If a defect is under-estimated in the inspection process, it can cause catastrophic failure or damage to the structure and include safety concerns for the community. 

Advanced UT known as Phased Array Ultrasonic Testing (PAUT) utilizes an array of transducers providing the capability of stirring and focusing the wave on a wider region and has a higher rate of flaw detection.  Thorough advancements in the form of the Total Focusing Method (TFM) and Full Matrix Capturing (FMC) significantly enhance and increase the accuracy and repeatability of the PAUT testing and inspection granting it many applications in the world of engineering.

In this project, samples of steel welds used in structures will be fabricated and tested for detection of the location, size, and properties of the flaws using UT techniques and compared to advanced PAUT techniques. With the goal of identifying a procedure that can be used for accurate detection of flaws considering their individual properties. To compare and validate the PAUT results, the identified locations of the defects will be tested for visual observation using optical and/or SEM microscopy techniques as well as conventional UT with a straight-beam single-element transducer. The validation and comparison steps will provide the level of accuracy and precision of UT as an NDT technique for steel infrastructures.

Methodology:

To conduct the experiment and for completion of the project, the following steps will be taken:

·       Design the experimental samples in SolidWorks

·       Manufacturing the samples using welding

·       Perform required machining and finishing processes

·       Perform UT tests to acquire defect characteristics

·       Perform Metallography and Scanning Electron Microscopy for structural assessment

·       Conduct traditional UT single-element transducer straight beam and angle wedge scans for weld quality assessment

·       Conduct Advanced PAUT scans for weld quality assessment

·       Compare findings of traditional UT and advanced PAUT

Presenting Author: Elsie Lappin Georgia Southern University

Presenting Author Biography: Elsie Lappin is a senior Civil Engineering student at Georgia Southern University. She currently completes undergraduate research in the LANDTIE Lab exploring Nondestructive Testing and Evaluation techniques for the Georgia Department of Transportation and the Federal Railroad Association to create safer transportation infrastructure. She serves as the president of the American Society of Nondestructive Testing- Coastal Georgia Section and plans to pursue graduate education upon the completion of her bachelor's degree.

Authors:

Elsie Lappin Georgia Southern University
Chowdhury Md Irtiza Georgia Southern University
Hossein Taheri Georgia Southern University
Saman Hedjazi Georgia Southern University
Bishal Silwal Georgia Southern University