Effect of initial pH and temperature of iron salt solutions on formation of magnetite nanoparticles

Advances, limitations and prospects of nondestructive testing and evaluation of thick composites and sandwich structures: A state-of-the-art review

Sizing of flaws using ultrasonic bulk wave testing: A review

This paper aims to provide an overview of the experimental and simulation works focused on the detection, localisation and assessment of various defects in pipes by applying fast-screening guided ultrasonic wave techniques that have been used in the oil and gas industries over the past 20 years. Major emphasis is placed on limitations, capabilities, defect detection in coated buried pipes under pressure and corrosion monitoring using different commercial guided wave (GW) systems, approaches to simulation techniques such as the finite element method (FEM), wave mode selection, excitation and collection, GW attenuation, signal processing and different types of GW transducers. The effects of defect parameters on reflection coefficients are also discussed in terms of different simulation studies and experimental verifications.

Detection, Localisation and Assessment of Defects in Pipes Using Guided Wave Techniques: A Review.

Simulation of ultrasonic phased array technique for imaging and sizing of defects using longitudinal waves

Inverse method for detection and sizing of cracks in thin sections using a hybrid genetic algorithm based signal parametrisation

New techniques developed using the array transducer, to image and size the bottom-surface and near-through-wall crack-like defects in thick carbon steel components are discussed. Three studies are reported here including (a) Optimal beam steering angle for focused and unfocused inspection using phased array method for bottom-surface crack sizing. (b) A front wall correction algorithm for sizing of near-through-wall crack-like defects. (c) A small aperture technique for sizing of near-through-wall crack-like defects. A Finite Difference Time Domain (FDTD) based simulation was used to study and verify the experimental observations. The application of time domain scheme relative arrival time technique (RATT), to measure the size of the near-through wall crack-like defects for the leak before break (LBB) criterion, was also investigated and found to be insufficient. A conventional SAFT algorithm was used for improving the sizing using the small aperture technique.

Sizing Cracks in Power Plant Components Using Array Based Ultrasonic Techniques

This paper reports the use of dispersive Higher Order Modes Guided Waves (HOM‐GW) and non‐dispersive Higher Order Modes Cluster Guided Waves (HOMC‐GW) for the detection and sizing of corrosion defects in pipes and tank floors. Pin‐hole and wall thinning defects of different sizes were artificially generated on the pipe and the tank floor specimens in order to simulate corrosion pits under pipe supports and tank floor annular plate regions respectively. Since, the nature of loss of material differs in each type of corrosion; the same mode excited cannot be effective in characterizing all the defect types, although they all may indicate the presence of defect. The effective modes are identified for each type of corrosion and their defect characterizing sensitivity was studied. The validity of this technique was tested with field samples.

Imaging hidden corrosion using ultrasonic non‐dispersive higher order guided wave modes

This article reports simulation studies of ultrasonic wave generation and reception using the sector scan feature of a phased array transducer to image and size crack-like defects in large pipes, elbows, and tee sections. The simulations were based on a two-dimensional implementation of the Finite Difference Time Domain (FDTD) method. Experiments were conducted to validate modeling results for pulse-echo simulations of the phased array transducer on pipe samples with notches of three different sizes. The defects were imaged using the sector scan mode of the phased array and sized using the Absolute Arrival Time Technique (AATT). A 64 element, 5 MHz linear phased array transducer with the ultrasonic beam swept over an angular range of 10°–75° (refracted angles), directly in contact with the specimen, was used. Simulation and experimental studies were also conducted to image and size cracks in elbow and tee section pipes.

L. Satyanarayan

Papers

Simulation of ultrasonic phased array technique for imaging and sizing of defects using longitudinal waves

Inverse method for detection and sizing of cracks in thin sections using a hybrid genetic algorithm based signal parametrisation

Sizing Cracks in Power Plant Components Using Array Based Ultrasonic Techniques

Imaging hidden corrosion using ultrasonic non‐dispersive higher order guided wave modes

Finite Difference Time Domain Simulation of Ultrasonic Phased Array Sector Scan for Imaging Cracks in Large Pipes, Elbows, and Tee Sections