Scattering of ultrasonic waves by internal anomalies in plates

Abstract

Real-time nondestructive testing ͑NDT͒ and nondestructive evaluation ͑NDE͒ of plate-type structures are important for structural health monitoring ͑SHM͒ applications. In this work, the wave scattering from horizontally oriented internal cavities or cracks in a plate is studied using the distributed point source method ͑DPSM͒. DPSM has gained popularity in the last few years in the field of ultrasonic field modeling. DPSM is a semianalytical technique that can be used to calculate the ultrasonic field ͑pressure, velocity, and displacement fields in a fluid, or stress and displacement fields in a solid͒ generated by ultrasonic transducers. So far, the technique has been used to model the ultrasonic field near a fluid-solid interface when a solid half-space is immersed in a fluid. This method has also been used to model the ultrasonic field generated in a homogeneous isotropic solid plate immersed in a fluid. The objective of this study is to present the theoretical modeling of the diffraction and scattering pattern of guided waves in the solid plate when transducers of finite dimension are used to generate guided waves in the defective plate.

Guided Waves for Nondestructive Testing – Experiment and Analysis

“…Interested readers are referred to a number of references provided in the text and in the fi gure captions for more detailed discussion and analysis. A solid plate (middle image) containing a crack near the bottom surface is struck by ultrasonic beams from two sides (top and bottom) of the plate [ 11,12 ] …”

“…It was extended to model phased array transducers [ 6 ] . DPSM was then generalized to model stress and displacement fi elds near a fl uid-solid interface [ 7 ] , in plates with uniform and non-uniform thickness [8][9][10] , and near cracks [11][12][13][14] .…”

Transient Propagation and Scattering of Quasi-Rayleigh Waves in Plates: Quantitative comparison between Pulsed TV-Holography Measurements and FC(Gram) elastodynamic simulations

“…Generally speaking, this assessment process implies, implicitly or explicitly, some kind of modelling of wave propagation and scattering [26], which is usually developed in the framework of the rigorous three-dimensional (3D) vector linear elasticity theory, in conjunction with a great variety of analytical or numerical schemes (e.g. normal mode expansion method [27], finite difference method [28], finite element method (FEM) [29], boundary element method [30], discrete point source method [31], local interaction simulation approach [32], various types of combinations or hybrid methods [33,34], etc.). In order to avoid the high computational cost typically associated to standard 3D simulation approaches in the high frequency regime, approximate theories (i.e.…”