Parastoo Bagheri; Sina Sodagar; Gholamreza Rashed; Amin Yaghootian
Abstract
Time-of-flight diffraction method (ToFD) is an amplitude-independent sizing method which is based on the measurement of time-of-flight of defect tip diffracted waves. Although ToFD can measure through-wall length of defect accurately, this method is not capable of measuring horizontal defect size. In ...
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Time-of-flight diffraction method (ToFD) is an amplitude-independent sizing method which is based on the measurement of time-of-flight of defect tip diffracted waves. Although ToFD can measure through-wall length of defect accurately, this method is not capable of measuring horizontal defect size. In this paper, a new ToFD method for evaluating horizontal planar defects is presented. The finite element method (FEM), using the ABAQUS software package, is employed to simulate the ultrasonic wave behavior in the test blocks and its interaction with the embedded planar defects. The phased array technology is also used to model the ultrasonic inspection system parameters. FEM simulation of the new ToFD method for different crack sizes shows that, compared to the conventional ToFD method, the accuracy of results is within acceptable range to use the novel technique for measuring the horizontal planar defects.
Kobra Kalvandi; Sina Sodagar
Abstract
Resonances are intrinsic characteristics of an elastic object, which are completely independent of the source of excitation. The appropriate utilization of the information contained within the resonance spectra and the identification of the resonance frequencies of the object can be used as a potent ...
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Resonances are intrinsic characteristics of an elastic object, which are completely independent of the source of excitation. The appropriate utilization of the information contained within the resonance spectra and the identification of the resonance frequencies of the object can be used as a potent tool for material characterization. In this paper, a new mathematical model for the wave diffraction from a cylindrical nanofiber encased in an elastic matrix is introduced. The new model is used to evaluate the scattered pressure field resulting from normal insonification on a single nanofibrous composite. It is shown that there are specific resonances, which arise from the surface/interface energy between the nanofiber and solid matrix. They can be used to determine the characteristics and properties of fibrous nanocomposites.
