A review on pipeline integrity management utilizing in-line inspection data

A review of ultrasonic testing applications in additive manufacturing: Defect evaluation, material characterization, and process control.

The use of piezoelectric wafer active sensors (PWAS) phased arrays for Lamb wave damage detection in thin-wall structures is presented. The PWAS capability to tune into specific Lamb-wave modes (which is an enabling factor for our approach) is first reviewed. Then, a generic beamforming formulation that does not require the conventional parallel-ray approximation is developed for PWAS phased arrays in connection with the delay-and-sum beamforming principles. This generic formulation is applied to a 1-D linear PWAS phased array. Particularly, 1-D PWAS array beamforming reduces to the simplified parallel ray algorithm when the parallel ray approximation is invoked. The embedded ultrasonic structural radar (EUSR) algorithm is presented. A couple of simple experiments are used to show that the linear EUSR PWAS phased array system can successfully detect cracks in large aluminum thin plates. To improve the EUSR image quality, advanced signal processing is studied for possible integration into the EUSR system. The approaches include Hilbert transform for envelope detection, thresholding techniques for removing background noise, discrete wavelet transform for denoising, continuous wavelet transform for single frequency component extraction, and cross-correlation for time-of-flight detection. The optimization of linear PWAS arrays is studied next. First we consider the effect of several parameters affecting the phased-array beamforming: (1) number of elements M; (2) elementary spacing d; (3) steering angle 0; (4) location of the target r. Second, we examine the so-called nonuniform PWAS arrays which are generated by assigning different excitation weights to each of the array elements. The design of two nonuniform linear PWAS arrays, the binomial array and the Dolph‐Chebyshev array, is presented. Significant improvement of the EUSR image is observed when using these nonuniform arrays.

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In-Situ Optimized PWAS Phased Arrays for Lamb Wave Structural Health Monitoring

Sizing of flaws using ultrasonic bulk wave testing: A review

A novel image enhancement algorithm based on stationary wavelet transform for infrared thermography to the de-bonding defect in solid rocket motors

A practical algorithm has been developed to increase the time resolution of an ultrasonic system for inspecting pipeline girth welds via deconvolution with autoregressive spectral extrapolation. The full-width-half-maximum of the analytic signal magnitude of experimental echo pulses was reduced by an average of 80% by this technique. There is also a reduction in the size of the dead zone at the weld root by close to 80%, in addition to a corresponding decrease in uncertainty of sizing estimates of cracks through crack-tip diffraction methods. The algorithm is used to inspect a test plate containing manufactured flaws with nominal depths ranging from 0.5 mm to 5 mm. Calculated values of crack depth were found to be consistent with destructive measurements of crack profiles.

Resolution enhancement of ultrasonic defect signals for crack sizing

Major improvements in weld inspection are obtained using Phased Array technology with capability for beam steering, electronic scanning, focusing, and sweeping the ultrasonic beams. Electronic scanning is much faster than raster scanning, and can optimize angles and focusing to maximize defect detection. Pressure vessel (PV) inspections typically use “top, side, end” or “top, side, TOFD” views, though other imaging is possible. Special inspections can be performed, e.g., for specific defects, or increased coverage. Defects can be sized by pulse-echo as per code, by time-of-flight Diffraction or by back diffraction. New PV inspection codes, particularly ASME Code Case 2235, permit the use of advanced ultrasonic inspection techniques. Pipeline girth weld inspections use a unique inspection approach called “zone discrimination,” and have their own series of codes. While similar equipment is used in pipeline as in PV inspections, the pipeline philosophy is to tailor the inspection to the weld profile and predicted lack of fusion defects. Pipeline displays are specifically designed for near real-time data analysis. Both ASME CC 2235 and the pipeline codes permit the use of Fitness-For-Purpose, which reduces construction costs. Overall, phased array systems meet or exceed all PV and pipeline codes.

Review of Ultrasonic Phased Arrays for Pressure Vessel and Pipeline Weld Inspections

Phased array ultrasonic inspection methods have been developed for the rapid inspection of Friction Stir Weldments (FSW) on Delta rocket cryogenic tanks. A comprehensive review was performed to identify NDE methods that are suitable for the detection of defects in this new welding process. The search included a review of traditional and advanced NDE methods that were capable of demonstrating both the sensitivity and inspection rates required for this examination. This paper will discuss the theory behind phased array techniques, fundamentals of several probe designs for FSW configurations, and the advantages of using phased arrays over conventional NDE methods for this applications.

Phased array ultrasonic inspection of Friction Stir Weldments

https://asmedigitalcollection.asme.org/IMECE/proceedings-pdf/doi/10.1115/IMECE2001/NDE-25815/6798226/119_1_imece2001-nde-25815.pdf

Inspection of Fastener Holes Using Ultrasonic Phased Arrays

Automated ultrasonics (AUT) is rapidly replacing radiography worldwide for gas pipeline girth weld inspections. Compared with radiography, mechanized ultrasonics is more reliable, faster, has better detection of critical Lack of Fusion defects, and poses no safety hazard. Phased arrays are the latest development in AUT, and present major improvements over conventional multiprobe ultrasonics. Phased array probe pans are lighter and smaller; scans are quicker due to the smaller probe pan; phased arrays are considerably more flexible for changes in pipe dimensions or weld profiles, and for different scan patterns for unusual defects; special scans can be made for specific problems. This paper describes the PipeWIZARD ultrasonic phased array system for girth weld inspections, based on the ASTM E-1961 code and compatible with API 1104 19 th Edition. Some comments on AUT codes will be made. The paper will describe the latest phased array UT results, plus developments like automated set-ups and improved imaging using an increased number of zones. PipeWIZARD’s track record and capabilities will be illustrated.

/pdf/pipeline-girth-weld-inspections-using-ultrasonic-phased-40vb63fvom.pdf

Michael Moles

Papers

Resolution enhancement of ultrasonic defect signals for crack sizing

Review of Ultrasonic Phased Arrays for Pressure Vessel and Pipeline Weld Inspections

Phased array ultrasonic inspection of Friction Stir Weldments

Inspection of Fastener Holes Using Ultrasonic Phased Arrays

Pipeline Girth Weld Inspections Using Ultrasonic Phased Arrays