Monitoring of Stamping Process Using Ultrasonic Waves

2016 ◽  
Author(s):  
S. Mishra ◽  
P. K. Kankar ◽  
M. Ishihama
Keyword(s):  
Automobile Industry ◽  
Ultrasonic Waves ◽  
Work Piece ◽  
Full Potential ◽  
Workpiece Material ◽  
Reflected Waves ◽  
Stamping Process ◽  
Transmitted Waves ◽  
The Press ◽  
The Waves

Stamping is a core manufacturing process in automobile industry. The measurement of the press force in stamping process has been the major focus of the research in this area. However, it has been established that the press force is itself an integral of the pressure distribution over the contact surfaces. Also full potential of servo-control stamping machines has not yet been achieved due to lack of appropriate sensing functions. In this study, an effort has been made to monitor the stamping process with the help of ultrasonic waves. The waves are employed to obtain the contact conditions between the work piece and the die. It has been shown that the waveforms are affected not only by the workpiece material and its thickness but also by the angle of inclination. Results show that the reflected waves, being more sensitive than transmitted waves, are influenced by the change in work piece related parameters.

Imaging reflection-blind areas using transmitted PS-waves

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. S241-S250 ◽  
Author(s):  
Yi Luo ◽  
Qinglin Liu ◽  
Yuchun E. Wang ◽  
Mohammed N. AlFaraj
Keyword(s):  
Mode Conversion ◽  
Imaging Techniques ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Reflected Waves ◽  
Prestack Migration ◽  
Reflection Data ◽  
Time Migration ◽  
Transmitted Waves ◽  
Vsp Data

We illustrate the use of mode-converted transmitted (e.g., PS- or SP-) waves in vertical seismic profiling (VSP) data for imaging areas above receivers where reflected waves cannot illuminate. Three depth-domain imaging techniques — move-out correction, common-depth-point (CDP) mapping, and prestack migration — are described and used for imag-ing the transmitted waves. Moveout correction converts an offset VSP trace into a zero-offset trace. CDP mapping maps each sample on an input trace to the location where the mode conversion occurs. For complex media, prestack migration (e.g., reverse-time migration) is used. By using both synthetic and field VSP data, we demonstrate that images derived from transmissions complement those from reflections. As an important application, we show that transmitted waves can illuminate zones above highly de-viated or horizontal wells, a region not imaged by reflection data. Because all of these benefits are obtained without extra data acquisition cost, we believe transmission imag-ing techniques will become widely adopted by the oil in-dustry.

The Template Matching Research Based on Multiple Images Fusion

2013 ◽  
Vol 655-657 ◽  
pp. 993-999
Author(s):  
Chang Jie Liu ◽  
Jia Jing Pi ◽  
Sheng Hua Ye
Keyword(s):  
Measurement Error ◽  
Automobile Industry ◽  
Template Matching ◽  
Visual Inspection ◽  
Online Monitoring ◽  
Work Piece ◽  
Mean Square ◽  
Multiple Images ◽  
Online Monitoring System ◽  
Mean Square Difference

Visual inspection has been widely used in the field of automobile industry. On a car production line, we use an online monitoring system to measure the same feature region of a work piece. Traditionally one picture is chosen as the template and used for other target measurements. However, this method tends to causing measurement error. In this paper a new algorithm is proposed which can generate a better template by multiple pictures. The process is as following: we firstly match the feature area; secondly, the gray information of this area is segmented; then after optimizing a new template is finally formed. The experimental results show that the NMSD (Normalized Mean Square Difference) is 0.0047 when we use the old template to match 10 pictures, but with the new one, the NMSD is only 0.0005. These results show that the new template is more accurate and stable.

DISBOND DETECTION TECHNIQUE FOR LINER/PROPELLANT INTERFACE USING ULTRASONIC RESONANCE AND LAMB WAVES

2012 ◽  
Vol 06 ◽  
pp. 49-54
Author(s):  
DONG-RYUN KIM ◽  
JAE-HOON KIM
Keyword(s):  
Lamb Waves ◽  
Resonance Method ◽  
Multilayered Structure ◽  
Ultrasonic Waves ◽  
Multilayered Structures ◽  
Reflected Waves ◽  
Nondestructive Tests ◽  
Ultrasonic Resonance ◽  
A New Technique ◽  
Insulation Liner

Adhesive interface tests using ultrasonic waves are far superior to other nondestructive tests for detecting the disbond interface. However, a multilayered structure consisting of a steel case, rubber insulation, liner, and propellant poses many difficulties for analyzing ultrasonic waves because of the superposition of the reflected waves and the large differences in the acoustic impedances of the various materials. Therefore, ultrasonic tests for detecting the disbond interface of multilayered structures have been applied in very limited areas between the steel case and rubber insulation using an automatic system. The existing ultrasonic test cannot detect the disbond interface between the rubber and propellant of a multilayered structure because most of the ultrasonic waves are absorbed in the rubber material, which has low acoustic impedance. This problem could be overcome by amplifying the ultrasonic waves using the ultrasonic resonance method. The Lamb waves were used to evaluate the instability of the ultrasonic waves caused by the contact condition on the surface of the multilayered structure. In this paper, a new technique to detect the disbond interface between the liner and propellant using the property of ultrasonic resonance and Lamb waves is discussed in detail.

Parametric Optimization of EN-31 Steel in Wire Cut Electro Discharge Machining by Taguchi Technique

2020 ◽  
Vol 12 (7) ◽  
pp. 881-887
Author(s):  
Sahil Sharma ◽  
Umesh Kumar Vates ◽  
Amit Bansal
Keyword(s):  
Material Removal Rate ◽  
Automobile Industry ◽  
Material Removal ◽  
Removal Rate ◽  
Dimensional Accuracy ◽  
Work Piece ◽  
Electro Discharge Machining ◽  
En 31 ◽  
The Impact ◽  
Dies And Moulds

Amongst the various methods of machining, Electro Discharge Machining is the convenient alternatives for the industries due to non-contact of work piece and tool. In the study of various EDM processes the main target is to achieve the better finish of surface, high material removal rate and good dimensional accuracy by regulating the different input parameters. There are various applications of EDM such as aerospace parts, medical equipments, dies and moulds, nuclear and automobile industry. In this experimental study, a trial has made to look the impact of input factors like pulse-on, pulse-off, peak current, tension of wire on rate of material removal, gap current and time for machining. Taguchi (L9 OA) and Analysis of Variance technique were used to optimize the outcomes for wire cut EDM of EN-31 tool steel. The outcomes revealed that Ton and Toff are the leading cogent factor for material removal rate and gap current respectively.

Inversion of a seismic transmission response

Geophysics ◽  
2001 ◽  
Vol 66 (4) ◽  
pp. 1235-1239
Author(s):  
Enders A. Robinson
Keyword(s):  
Inverse Problems ◽  
Remote Detection ◽  
Inverse Source Problem ◽  
Reflection Seismology ◽  
Reflected Waves ◽  
Active Sonar ◽  
Transmitted Waves ◽  
Source Signal ◽  
Inverse Medium ◽  
Inverse Medium Problem

Traveling waves are used not only in exploration geophysics but also in other disciplines faced with remote detection problems. A physical system may be described in terms of the input (the source), the medium, and the output (the received signal). The received signal can be made up of either transmitted waves or reflected waves. Two types of inverse problems can be considered, namely, the inverse source problem and the inverse medium problem. In the inverse source problem, the objective is to determine the source. In the inverse medium problem, the objective is to determine the medium. Thus, in terms of this general classification, four types of problems can be encountered, namely, an inverse source problem with transmitted waves, an inverse source problem with reflected waves, an inverse medium problem with transmitted waves, and an inverse medium problem with reflected waves. Let us look at nature. Twinkle, twinkle, little star. The transmission of starlight though the atmosphere makes the star twinkle. A better image of the star can be obtained by solving an inverse source problem using the transmitted starlight. In the typical inverse source problem, the source of energy is remote, the medium transmits the source signal, and the received data are the transmitted waves. Examples are classical earthquake seismology, radio transmission, and passive sonar. Shakespeare said; “For the eye sees not by itself, but by reflection.” Thus the miracle of eyesight solves an inverse medium problem that uses reflected waves. In the typical inverse medium problem, the source of energy is local and often man‐made, the medium reflects the source signal, and the received data are the reflected waves. Examples are reflection seismology, radar, and active sonar. Thus, the two principle types of inverse problems encountered in nature are the inverse source problem with transmitted waves and the inverse medium problem with reflected waves.

Broadband Random Phase Diffuser for Ultrasonic Imaging

1979 ◽  
Vol 1 (4) ◽  
pp. 325-332
Author(s):  
Gerard A. Alphonse ◽  
David Vilkomerso
Keyword(s):  
Solid Angle ◽  
Random Phase ◽  
Ultrasonic Imaging ◽  
Standing Waves ◽  
Acoustic Imaging ◽  
Point Sources ◽  
Phase Plate ◽  
Reflected Waves ◽  
Large Aperture ◽  
The Waves

In reflective imaging, waves must be scattered by the object over a broad solid angle so that some of the reflected waves impinge upon the collecting aperture. Surfaces such as biological specimens under study in acoustic imaging are considered smooth at the wavelengths used (e.g., 1 mm) and therefore act as specular reflectors. In order to obtain reflection over a broad spatial range, large aperture, sector or compound scanning are used. In certain types of systems, diffuse insonification is sometimes used by imaging a raster of random phase points onto the surface. However interference between the waves from these point sources produces random fringes or “speckle-like” patterns overlaying the image. In optics these fringes have been reduced by rotating the diffuser. A similar approach has been taken here. This paper describes a simple random phase plate having two levels, 0° and 180 phase that can, by rotation, change the relative phases of the diffuse insonification points so as to reduce the speckle-like effect in the image. The temporal bandwidth of the random phase plate is narrow because of standing waves in it. To reduce standing waves the diffuser is intimately coupled to a wedged transducer. This combination is used to obtain diffuse insonification with broad spatial and temporal bandwidth.

Numerical modelling of MHD waves in the solar chromosphere

2005 ◽  
Vol 364 (1839) ◽  
pp. 395-404 ◽  
Author(s):  
Mats Carlsson ◽  
Thomas J Bogdan
Keyword(s):  
Magnetic Field ◽  
Acoustic Waves ◽  
Mode Conversion ◽  
Three Dimensions ◽  
Mhd Waves ◽  
Solar Chromosphere ◽  
Fast Mode ◽  
Reflected Waves ◽  
The Waves ◽  
The Magnetic Field

Acoustic waves are generated by the convective motions in the solar convection zone. When propagating upwards into the chromosphere they reach the height where the sound speed equals the Alfvén speed and they undergo mode conversion, refraction and reflection. We use numerical simulations to study these processes in realistic configurations where the wavelength of the waves is similar to the length scales of the magnetic field. Even though this regime is outside the validity of previous analytic studies or studies using ray-tracing theory, we show that some of their basic results remain valid: the critical quantity for mode conversion is the angle between the magnetic field and the k-vector: the attack angle. At angles smaller than 30° much of the acoustic, fast mode from the photosphere is transmitted as an acoustic, slow mode propagating along the field lines. At larger angles, most of the energy is refracted/reflected and returns as a fast mode creating an interference pattern between the upward and downward propagating waves. In three-dimensions, this interference between waves at small angles creates patterns with large horizontal phase speeds, especially close to magnetic field concentrations. When damping from shock dissipation and radiation is taken into account, the waves in the low–mid chromosphere have mostly the character of upward propagating acoustic waves and it is only close to the reflecting layer we get similar amplitudes for the upward propagating and refracted/reflected waves. The oscillatory power is suppressed in magnetic field concentrations and enhanced in ring-formed patterns around them. The complex interference patterns caused by mode-conversion, refraction and reflection, even with simple incident waves and in simple magnetic field geometries, make direct inversion of observables exceedingly difficult. In a dynamic chromosphere it is doubtful if the determination of mean quantities is even meaningful.

scholarly journals The Pyramid – Resonator of waves

2021 ◽  
Author(s):  
Junaid Aziz
Keyword(s):  
Energy Transport ◽  
Golden Ratio ◽  
Single Point ◽  
Fibonacci Number ◽  
Sine Wave ◽  
Curved Surface ◽  
Reflected Waves ◽  
Great Pyramid ◽  
The Law ◽  
The Waves

The Great Pyramid of Giza has fascinated us all as it encodes enormous amount of numerical coincidences such as dimensional precision, movement of our planet, speed of light, the golden ratio of Pi & Phi, etc.Studies have reasoned that the great pyramid of Giza has expressed the key ratio of an AC voltage sine wave as well as the ratios of Fibonacci number in developing the pyramidal design. Therefore in this study, the pyramid structure is considered as a resonator of waves where reflection of waves is an obvious phenomenon. The waves entering the pyramidal resonator will be reflected inward as they reflect from a curved surface according to the law of reflection. Since, a reflecting wave involves the energy-transport process, it determines our main objective to review and internalize the energy caused by reflection of the waves which occurs inside the pyramidal resonator. It is assumed that there is a strength point of such energy due to a higher volume of reflected waves to a single point. According to the law of reflection, when reflection occurs through a curved surface, it focuses incoming parallel waves to a convergence spot. This project is subjected to study the pyramid as a resonator of waves and aims to detect, observationally, the strength point of energy assumed to be caused by maximum number of reflected waves.

scholarly journals UPWIND TRAVEL OF REFLECTED WAVES

1968 ◽  
Vol 1 (11) ◽  
pp. 14
Author(s):  
E.P. Richey
Keyword(s):  
Wind Waves ◽  
Full Scale Test ◽  
Deep Lake ◽  
Reflected Waves ◽  
Wind Speeds ◽  
Wave Characteristics ◽  
Wave Heights ◽  
Scale Test ◽  
Floating Bridges ◽  
The Waves

Wind waves in a lake have been observed to reflect from a barrier and to travel upwind for considerable distances. A model has been devised which provides a means of predicting the decay of these waves as a function of wind speed and direction with respect to the barrier. Two floating bridges across a deep lake have formed a convenient, full-scale test basin for the formation and observation of the reflected waves under a range of wind speeds and directions. Wave characteristics have been measured to a limited extent by photographic means, a portable wave probe and visually to provide seme verification of the results computed from the model. The measured and the predicted wave heights and the zones influenced by the waves were found to be in general qualitative agreement.

scholarly journals Incidence and reflection of internal waves and wave-induced currents at a jump in buoyancy frequency

2014 ◽  
Vol 1 (1) ◽  
pp. 269-315
Author(s):  
J. P. McHugh
Keyword(s):  
Wave Packet ◽  
Internal Gravity Waves ◽  
Buoyancy Frequency ◽  
Mean Flow ◽  
Weakly Nonlinear ◽  
Transmitted Waves ◽  
The Mean ◽  
Induced Currents ◽  
Wave Induced ◽  
The Waves

Abstract. Weakly nonlinear internal gravity waves are treated in a two-layer fluid with a set of nonlinear Schrodinger equations. The layers have a sharp interface with a jump in buoyance frequency approximately modelling the tropopause. The waves are periodic in the horizontal but modulated in the vertical and Boussinesq flow is assumed. The equation governing the incident wave packet is directly coupled to the equation for the reflected packet, while the equation governing transmitted waves is only coupled at the interface. Solutions are obtained numerically. The results indicate that the waves create a mean flow that is strong near and underneath the interface, and discontinuous at the interface. Furthermore, the mean flow has an oscillatory component with a vertical wavelength that decreases as the wave packet interacts with the interface.

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