Based on rigorous theoretical findings, we present a proof-of-concept design for a structured square cloak enclosing a void in an elastic lattice. We implement high-precision fabrication and experimental testing of an elastic invisibility cloak for flexural waves in a mechanical lattice. This is accompanied by verifications and numerical modelling performed through finite element simulations. T...

It is important to examine the factors that determine the properties of graphene. Various factors affect the properties of graphene nanosheets that can revolutionize the use of graphene. One such factor is ultrasonic waves, which have significant effects on graphene properties. In this research, we studied the effect of ultrasonic waves with different power levels (35, 50, 360, and 420 W) on fo...

Using numerical simulations, we investigated the responses of the π-phase-shifted fiber Bragg gratings (πFBGs) impinged by pressure ultrasonic waves. The effect of the grating length, grating refractive index modification depth, and ultrasonic frequency on the wavelength sensitivity and intensity sensitivity of the πFBG ultrasonic sensor for ultrasonic waves of different wavelengths was analyze...

non-destructive ultrasonic testing is one of the methods utilized to evaluate quality of agricultural produce. transducers used in this method are made for basically industrial applications. since ultrasonic attenuation of waves in agricultural produce is very high, industrial transducers cannot be used in agriculture and needs to be modified. this is done with horns that concentrate energy on ...

al’s properties and acoustical characteristics have been studied for a long time and ultrasonic techniques have been used in non-destructive testing and imaging for decades. Ultrasound as an analytical tool has revolutionised diagnostics in medicine, but the application of ultrasound to material’s analyses has been held back by problems with ultrasonic design, electronics, sample handling, comp...

Compared with conventional linear ultrasonic inspection methods, which are sensitive only to severe defects, nonlinear ultrasonic inspection methods are better for revealing micro-cracks in thin plates. However, most nonlinear ultrasonic inspection methods have only been experimentally investigated using bulk or Rayleigh waves. Numerical studies, especially numerical simulations of Lamb ultraso...

The application of laser ultrasonic technique is developed for evaluation of friction stir spot welding (FSSW) quality. The features of laser-generated ultrasonic waves in good welding and incomplete fusion area are simulated by finite element method (FEM). The non-contact laser ultrasonic inspection system (LUIS) was established to verify the numerical results. The interaction of laser ultraso...

Abstract For visualizing ultrasonic propagation, we have developed a generation laser scanning method. This method has the following features that make it superior to the conventional visualization methods such as the photo-elasticity method and the reception probe scanning method. (1) It enables us to visualize ultrasonic waves propagating on a complexly shaped object. (2) It makes high-speed ...

If it were possible to perform ultrasonic inspections while observing the propagation of ultrasonic waves as dynamic images, the identification of defect echoes would become easier, and inspection, quicker. Furthermore, fewer defects would be overlooked or improperly identified, leading to higher-reliability inspections. For visualizing ultrasonic propagation, we have developed a generation las...

Direct experimental evidence is given to show that the traditional viewpoint of polarization reversal must be modified to include the path of consecutive non-180◦ domain switching. Using ultrasonic waves, we have successfully monitored multi-domain formation during the polarization switching cycle in a bulk single crystal 0.955Pb(Zn1/3Nb2/3)O3-0.045PbTiO3. A model is proposed for the polarizati...