Ultrasonic Vibration Characteristics of Nano-Composite Ceramic in the Ultrasonic Polishing Process

2012 ◽  
Vol 522 ◽  
pp. 147-151
Author(s):  
Ming Zhang ◽  
Feng Jiao
Keyword(s):  
Surface Waves ◽  
High Efficiency ◽  
Three Dimensional ◽  
Wave Theory ◽  
Composite Ceramic ◽  
Ceramic Plate ◽  
Two Dimensional ◽  
Nano Composite ◽  
The Waves ◽  
Order Surface

The ultrasonic polishing test of the nanoZrO2-Al2O3composite ceramics is done under the two-dimensional ultrasonic polishing device, which is developed by us. In this process, the ultrasonic amplitude-frequency characteristic testing is done by the DASP software. There are certain amplitudes at some frequency points, which can be seen from the spectrum and the three-dimensional spectral array maps, but only one the largest amplitude appears. This shows the resonance points appear when the ultrasonic is passed to the nanocomposite ceramic plate after it is amplified by the horn. This phenomenon is analyzed by the second-order surface wave theory and the waves are surface waves, which are generated by surface waves. These explain the good polishing surface quality and high efficiency under the two-dimensional ultrasonic polishing in the same conditions.

Ultrasonic Characteristics of the Ultrasonic Grinding Process about the Nano-Ceramic Plate

2011 ◽  
Vol 418-420 ◽  
pp. 1690-1693 ◽  
Author(s):  
Ming Zhang ◽  
Yu Qing Wang ◽  
Feng Jiao
Keyword(s):  
High Efficiency ◽  
Skin Effect ◽  
Wave Theory ◽  
Ultrasonic Waves ◽  
Grinding Process ◽  
Ceramic Plate ◽  
Two Dimensional ◽  
Ultrasonic Grinding ◽  
The Waves ◽  
Order Surface

In this paper, the sand vibration test of the ultrasonic wave is done under ultrasonic vibration grinding. In this test, the "skin effect"is observed when the ultrasonic waves pass to the nano-ceramic plate, which is amplified by the ultrasonic horn. This phenomenon is analyzed by the second-order surface wave theory and the waves which pass to the workpiece are surface waves generated. These explain the good grinding surface quality and high efficiency under the two-dimensional ultrasonic grinding in the same conditions.

Steady State Motion and Surface Waves

1996 ◽  
Author(s):  
T. T. C. Ting
Keyword(s):  
Steady State ◽  
Surface Wave ◽  
Surface Waves ◽  
Existence And Uniqueness ◽  
Wave Speed ◽  
Wave Theory ◽  
Two Dimensional ◽  
Elastic Materials ◽  
Steady State Motion ◽  
Anisotropic Elastic

The Stroh formalism for two-dimensional elastostatics can be extended to elastodynamics when the problem is a steady state motion. Most of the identities in Chapters 6 and 7 remain applicable. The Barnett-Lothe tensors S, H, L now depend on the speed υ of the steady state motion. However S(υ), H(υ), L(υ) are no longer tensors because they do not obey the laws of tensor transformation when υ≠0. Depending on the problems the speed υ may not be prescribed arbitrarily. This is particularly the case for surface waves in a half-space where υ is the surface wave speed. The problem of the existence and uniqueness of a surface wave speed in anisotropic materials is the crux of surface wave theory. It is a subject that has been extensively studied since the pioneer work of Stroh (1962). Excellent expositions on surface waves for anisotropic elastic materials have been given by Farnell (1970), Chadwick and Smith (1977), Barnett and Lothe (1985), and more recently, by Chadwick (1989d).

A note on the total reflexion or transmission of surface waves in the presence of parallel obstacles

1975 ◽  
Vol 67 (3) ◽  
pp. 465-472 ◽  
Author(s):  
D. V. Evans
Keyword(s):  
Surface Wave ◽  
Surface Waves ◽  
Water Wave ◽  
Wave Theory ◽  
Two Dimensional ◽  
Total Transmission ◽  
Vertical Barriers ◽  
Total Reflexion ◽  
Dimensional Surface

It is shown how a two-dimensional surface wave can be either totally reflected or totally transmitted in the presence of two parallel vertical barriers each containing a small gap. Total transmission of a surface wave past obstacles has been known to occur in many situations in water-wave theory, but total reflexion is a comparatively new phenomenon which could be of practical use in the design of breakwaters.

scholarly journals On the Potential of 3D Transdimensional Surface Wave Tomography for Geothermal Prospecting of the Reykjanes peninsula

2021 ◽  
Author(s):  
Amin Rahimi Dalkhani ◽  
Xin Zhang ◽  
Cornelis Weemstra
Keyword(s):  
Surface Wave ◽  
Surface Waves ◽  
Velocity Structure ◽  
Voronoi Tessellation ◽  
Three Dimensional ◽  
Seismic Network ◽  
Two Dimensional ◽  
Travel Times ◽  
Model Resolution ◽  
Reykjanes Peninsula

Seismic travel time tomography using surface waves is an effective tool for three-dimensional crustal imaging. Historically, these surface waves are the result of active seismic sources or earthquakes. More recently, however, also surface waves retrieved through the application of seismic interferometry are exploited. Conventionally, two-step inversion algorithms are employed to solve the tomographic inverse problem. That is, a first inversion results in frequency-dependent, two-dimensional maps of phase velocity, which then serve as input for a series of independent, one-dimensional frequency-to-depth inversions. As such, a two-dimensional grid of localized depth-dependent velocity profiles are obtained. Stitching these separate profiles together subsequently yields a three-dimensional velocity model. Relatively recently, a one-step three-dimensional non-linear tomographic algorithm has been proposed. The algorithm is rooted in a Bayesian framework using Markov chains with reversible jumps, and is referred to as transdimensional tomography. Specifically, the three-dimensional velocity field is parameterized by means of a polyhedral Voronoi tessellation. In this study, we investigate the potential of this algorithm for the purpose of recovering the three-dimensional surface-wave-velocity structure from ambient noise recorded on and around the Reykjanes Peninsula, southwest Iceland. To that end, we design a number of synthetic tests that take into account the station configuration of the Reykjanes seismic network. We find that the algorithm is able to recover the 3D velocity structure at various scales in areas where station density is high. In addition, we find that the standard deviation on the recovered velocities is low in those regions. At the same time, the velocity structure is less well recovered in parts of the peninsula sampled by fewer stations. This implies that the algorithm successfully adapts model resolution to the density of rays. Also, it adapts model resolution to the amount of noise on the travel times. Because the algorithm is computationally demanding, we modify the algorithm such that computational costs are reduced while sufficiently preserving non-linearity. We conclude that the algorithm can now be applied adequately to travel times extracted from (time-averaged) station-station cross correlations by the Reykjanes seismic network.

scholarly journals Using a Three-Dimensional Reduction Method in the High-Efficiency Grain Selector and Corresponding Grain Selection Mechanism

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1781
Author(s):  
Xintao Zhu ◽  
Fu Wang ◽  
Shuaipeng Zhang ◽  
Tobias Wittenzellner ◽  
Jessica Frieß ◽  
...  
Keyword(s):  
Single Crystal ◽  
High Efficiency ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Selection Mechanism ◽  
Dimensional Reduction Method ◽  
Optimization Parameters ◽  
Dimensional Coupling

In the development of a high-efficiency grain selector, the spiral selectors are widely used in Ni-based single crystal (SX) superalloys casting to produce single crystal turbine blades. For the complex three-dimensional structure of the spiral, a 2D grain selector was designed to investigate in this paper. As a result, the parameters of two-dimensional grain selection bond and the corresponding grain selection mechanism were established, and the three-dimensional grain selection bond was designed again by means of two-dimensional coupling optimization parameters.

scholarly journals Wave resistance: Some cases of three-dimensional fluid motion

1919 ◽  
Vol 95 (670) ◽  
pp. 354-365 ◽  
Keyword(s):  
Surface Pressure ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Wave Resistance ◽  
The Other ◽  
Two Dimensional ◽  
Pressure System ◽  
Submerged Body ◽  
Submerged Sphere ◽  
The Waves

1. Calculations of wave resistance, corresponding to a pressure system travelling over the surface, have hitherto been limited to two-dimensional fluid motion; in those cases, the distribution of pressure on the surface is one-dimensional, and the regular waves produced have straight, parallel crests. The object of the following paper is to work out some cases when the surface pressure is two-dimensional and the wave pattern is like that produced by a ship. A certain pressure system symmetrical about a point is first examined, and more general distributions are obtained by superposition. By combining two simple systems of equal magnitude, one in rear of the other, we obtain results which show interesting interference effects. In similar calculations with line pressure systems, at certain speeds the waves due to one system cancel out those due to the other, and the wave resistance is zero; the corresponding ideal form of ship has been called a wave-free pontoon. Such cases of perfect interference do not occur in three-dimensional problems; the graph showing the variation of wave resistance with velocity has the humps and hollows which are characteristic of the resistance curves of ship models. Although the main object is to show how to calculate the wave resistance for assigned surface pressures of considerable generality, it is of interest to interpret some of the results in terms of a certain related problem. With certain limitations, the waves produced by a travelling surface pressure are such as would be caused by a submerged body of suitable form. The expression for the wave resistance of a submerged sphere, given in a previous paper, is confirmed by the following analysis. It is also shown how to extend the method to a submerged body whose form is derived from stream lines obtained by combining sources and siuks with a uniform stream; in particular, an expression is given for the wave resistance of a prolate spheroid moving in the direction of its axis.

scholarly journals Wave concept of motion in mathematical models of the dynamics of two-dimensional media studying

2019 ◽  
Vol 5 (3-4) ◽  
pp. 8-15
Author(s):  
Andrij Andrukhiv ◽  
◽  
Bohdan Sokil ◽  
Mariia Sokil ◽  
◽  
...  
Keyword(s):  
Mathematical Models ◽  
Asymptotic Methods ◽  
Wave Theory ◽  
Single Frequency ◽  
Two Dimensional ◽  
Klein Gordon ◽  
Basic Parameters ◽  
The Impact ◽  
The Mathematical Model ◽  
The Waves

The methodology of the studying of dynamic processes in two-dimensional systems by mathematical models containing nonlinear equation of Klein-Gordon was developed. The methodology contains such underlying: the concept of the motion wave theory; the single - frequency fluctuations principle in nonlinear systems; the asymptotic methods of nonlinear mechanics. The aggregate content allowed describing the dynamic process for the undisturbed (linear) analogue of the mathematical model of movement. The value determining the impact of nonlinear forces on the basic parameters of the waves for the disturbed analogue is defined.

scholarly journals A Numerical Approach for Calculation of Characteristics of Edge Waves in Three-Dimensional Plates

2020 ◽  
pp. 2050014
Author(s):  
Wenbo Duan ◽  
Ray Kirby
Keyword(s):  
Numerical Model ◽  
Nondestructive Testing ◽  
Surface Waves ◽  
Three Dimensional ◽  
Love Waves ◽  
Mode Shapes ◽  
Finite Width ◽  
Two Dimensional ◽  
Edge Waves ◽  
Rayleigh And Love Waves

Surface waves have been extensively studied in earthquake seismology. Surface waves are trapped near an infinitely large surface. The displacements decay exponentially with depth. These waves are also named Rayleigh and Love waves. Surface waves are also used for nondestructive testing of surface defects. Similar waves exist in finite width three-dimensional plates. In this case, displacements are no longer constant in the direction perpendicular to the wave propagation plane. Wave energy could still be trapped near the edge of the three-dimensional plate, and hence the term edge waves. These waves are thus different to the two-dimensional Rayleigh and Love waves. This paper presents a numerical model to study dispersion properties of edge waves in plates. A two-dimensional semi-analytical finite element method is developed, and the problem is closed by a perfectly matched layer adjacent to the edge. The numerical model is validated by comparing with available analytical and numerical solutions in the literature. On this basis, higher order edge waves and mode shapes are presented for a three-dimensional plate. The characteristics of the presented edge wave modes could be used in nondestructive testing applications.

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