Simultsonic: A Simulation Tool for Ultrasonic Inspection

Phased Array Ultrasonic Measurement of Fatigue Crack Growth Profiles in Stainless Steel Pipes

Abstract: This paper reports experimental sizing of fatigue crack profiles that are initiated from artificially made circumferential starter notches in stainless steel pipes of 169 mm outer diameter and 14.33 mm thickness, which were subjected to cyclic bending loads in a four point bending load arrangement using two nondestractive evaluation (NDE) methods: (a) phased array ultrasonic technique and (b) alternating current potential drop technique. The crack growth estimated using the two NDE techniques were compared with the beach marks that were present in the fracture surface. A simulation study using the ray tracing method was carried out to model the ultrasonic wave propagation in the test specimen, and the results were compared with the experimental results.

A Simulation Tool for Ultrasonic Inspection

Abstract: A simulation program SIMULTSONIC is under development at CNDE to help determine and/or help optimize ultrasonic probe locations for inspection of complex components. SIMULTSONIC provides a ray-trace based assessment for immersion and contact modes of inspection. The code written in Visual C++ operating in Microsoft Windows environment provides an interactive user interface. In this paper, a description of the various features of SIMULTSONIC is given followed by examples illustrating the capability of SIMULTSONIC to deal with inspection of canonical objects such as pipes. In particular, the use of SIMULTSONIC in the inspection of very thin-walled pipes (with 450 urn wall thickness) is described. Ray trace based assessment was done using SIMULTSONIC to determine the standoff distance and the angle of oblique incidence for an immersion mode focused transducer. A 3-cycle Hanning window pulse was chosen for simulations. Experiments were carried out to validate the simulations. The A-scans and the associated B-Scan images obtained through simulations show good correlation with experimental results, both with the arrival time of the signal as well as with the signal amplitudes.

Numerical Modelling Methods for Ultrasonic Wave Propagation Through Polycrystalline Materials

Abstract: The present article addresses the development at Centre for Non-destructive Evaluation, Indian Institute of Technology Madras, of three different numerical methods, namely finite element, ray tracing and finite-difference time-domain methods for investigating the propagation of ultrasonic waves through polycrystalline media. These methods are believed to aid in better understanding of ultrasonic wave interaction in materials exhibiting both simple and complex grain morphologies. The understanding is expected to provide an improved non-destructive assessment of material and defect characterisation.

Ultrasonic Testing of Materials

Abstract: Nondestructive testing of solid material using ultrasonic waves, for defects such as cavities, nonbonding, and strength variations, is treated in this book from the physical fundamentals of ultrasonics and materials up to the most sophisticated methods. The book is written at a level which should make it accessible to readers with some knowledge of technical mathematics. Physical laws are explained in elementary terms, and more sophisticated treatments are also indicated. After the fundamentals, instrumentation and its application is extensively reported. Tricks and observations from thirty years of experience in the field are included. The third part of the book presents test problems related to special materials or ranges of modern heavy industry, including recent applications such as those in nuclear power plants. This fourth edition features improved presentation of certain fundamental physical facts, updated reports on electronic instrumentation, and new applications in the nuclear and space industries.

A ray model for decimetric radiowave propagation in an urban area

Abstract: A ray-tracing model involving multiple reflections and diffractions is proposed to predict wideband decimetric radio wave propagation in an urban area. A computer code was developed in which only buildings close to the vehicle are considered. Wall irregularities and electromagnetic properties of material are taken into account by a constant reflection factor, while diffraction attenuation is computed from geometrical theory of diffraction results. Simulated channel path losses and complex impulse responses are compared with some measurements performed in Paris at a 900-MHz central frequency.