scholarly journals Preliminary Determination of the Optimal Parameters When Using an Ultrasonic Probe to Measure Cavern Geometry Where a Metal Borehole Pipe Is Present

Acoustics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 425-441
Author(s):  
Kubacka Tomasz ◽  
Nguyen Dinh Chau
Keyword(s):  
Metal Plate ◽  
Ultrasonic Waves ◽  
Optimal Parameters ◽  
Optimal Frequency ◽  
Ultrasonic Probe ◽  
Ultrasonic Signals ◽  
Metal Pipe ◽  
Transmitted Waves ◽  
Metal Plates

In order to determine the optimal parameters when using an ultrasonic probe to measure cavern geometry when a metal borehole pipe is present, an investigation was firstly carried out on influence of a vertical metal plates with a thickness from 1 mm to 15 mm immersed in water on transmitted and reflected ultrasonic waves. The results obtained will be used as an indicator for the measurement of underground geometry in which the ultrasonic probe is placed inside a metal pipe lining a borehole. These studies were performed both by experiment and computer simulation. The results show that the wavelength of the incident ultrasonic signals should be equal to half the thickness of the metal plate or an integer times smaller than this thickness. When the thickness of the barrier is unknown, an ultrasonic signal with linear frequency modulation (LFM) should be used. Due to the reverberation of the ultrasonic waves inside the pipe for caverns filled with water, the distance from the transducer to the cavern wall can be measured if it is longer than three times of the pipe diameter. Frequency analysis of both the reflected and the transmitted waves enables an optimal frequency of the incident ultrasonic wave to be selected, which can be used in the measurement of cavern geometry in conditions in which the ultrasonic probe is inside a metal pipe.

FOCUSED ULTRASONIC WAVE IN SUBMERGED CANCELLOUS BONE

2005 ◽  
Vol 13 (04) ◽  
pp. 585-601 ◽  
Author(s):  
ROBERT P. GILBERT ◽  
WEI LIN ◽  
YONGZHI XU
Keyword(s):  
Ultrasonic Wave ◽  
Cancellous Bone ◽  
Clinical Applications ◽  
Ultrasonic Waves ◽  
Cylindrical Coordinates ◽  
Transmitted Waves ◽  
Biot Equations ◽  
Biot’S Equations

In this paper we present some results from our research on the interrogation of cancellous bone using ultrasound. Cancellous bone is known to be poroelastic in structure and, hence, Biot's equations may be applicable. In order to do the interrogation we consider using focused, ultrasonic, waves, symmetric about the axis of propagation. This suggests that we formulate the Biot equations using cylindrical coordinates. Our results provide relations involving the velocities of the transmitted waves and the Biot coefficients and these have clinical applications to the determination of osteoporosis of the cancellous bone.

scholarly journals Determination of Delay in Detonation of a Sandwiched Explosive Impacted by a Shaped Charge Jet

2020 ◽  
Vol 70 (4) ◽  
pp. 353-358
Author(s):  
H. S. Yadav
Keyword(s):  
Analytical Model ◽  
Metal Plate ◽  
Shaped Charge ◽  
Simple Analytical Model ◽  
Numerical Examples ◽  
Metal Plates ◽  
Jet Impact ◽  
Jet Penetration ◽  
Shaped Charge Jet

A simple analytical model has been developed to determine delay in detonation of an explosive sandwiched between two metal plates and impacted by a shaped charge jet. The analytical model consists of a relation between detonation delay and depth of jet penetration in a target kept in contact across the explosive sandwich. This relation is derived by expressing depth of jet penetration P as a function of detonation delay Tdx and duration Tw of free passage of the jet through the hole in the top plate of the sandwich. One more relation between Tdx and Tw has been obtained from the theory of expansion of hole produced in a metal plate by jet impact. These two relations have been solved simultaneously to get values of both these parameters as a function of jet penetration. It is proposed that this analytical model can be used in two ways. First, this model can be used to calculate detonation delay by experimental measurement of jet penetration in a target. The detonation delay thus determined can be used to calculate insensitivity constant Aj of an explosive. Second, this model can be used to theoretically calculate jet penetrations obtained by different shaped charge warheads when using a sandwich of explosive with a given insensitivity. Both uses of this analytical model are illustrated using numerical examples.

scholarly journals Determination of Optimal Frequency to Replace Cutting Elements in Chain Trenchers

2021 ◽  
Vol 1118 (1) ◽  
pp. 012026
Author(s):  
S M Kravchenko ◽  
V A Slepchenko ◽  
I V Slepchenko
Keyword(s):  
Optimal Frequency

Determination of the optimal frequency of reversing the flame of open-hearth furnaces

Metallurgist ◽  
1964 ◽  
Vol 8 (5) ◽  
pp. 241-242
Author(s):  
N. K. Korneva ◽  
G. A. Dorofeev ◽  
I. P. Grinevich ◽  
E. B. Vinokurov
Keyword(s):  
Open Hearth ◽  
Optimal Frequency

Determination of the foaming parameters of polyurethane compositions from the velocity of longitudinal ultrasonic waves

1979 ◽  
Vol 15 (3) ◽  
pp. 316-317 ◽  
Author(s):  
V. M. Mel'nikov ◽  
�. A. Putnin'sh ◽  
V. O. Putninya ◽  
V. P. Karlivan
Keyword(s):  
Ultrasonic Waves ◽  
Longitudinal Ultrasonic Waves

Analysis on Metal Plate Connection Property of Larch Dimension Lumber

2012 ◽  
Vol 174-177 ◽  
pp. 2170-2175
Author(s):  
Rong Jun Zhao ◽  
Jun Zhen Zhang ◽  
Hai Bin Zhou ◽  
Ben Hua Fei
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Metal Plate ◽  
Seismic Structure ◽  
Performance Parameters ◽  
Metal Plates ◽  
Dimension Lumber ◽  
Design Value ◽  
Plate Connection ◽  
Ductility Ratio

In this study, Larix gemilinii and metal plate were selected as the main materials. According to GB5005-2003, the connection properties of tension-splice joint and larch wood were investigated. The results showed that the elastic modulus of Larix gemilinii was not affected by the performance parameters of tension-splice joint greatly and three kinds of failure modes were introduced. Besides the design value for the ultimate bearing capacity of Larix gemilinii and the design value for the ultimate tensile bearing capacity of the metal plates were determined. A conservative calculation method for ductility ratio of metal plates was proposed. The ductility ratio of the metal plate connected joint changed with the construction modes, and the ductility ratio for metal plate parallel to the grain (more than 2.4) was obviously bigger than that of perpendicular to the grain, which complies with the requirements for ductility ratio in anti-seismic structure.

Determination of optimal parameters of the tuned mass damper to reduce the torsional vibration of the shaft by using the principle of minimum kinetic energy

2018 ◽  
Vol 233 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Duy-Chinh Nguyen
Keyword(s):  
Kinetic Energy ◽  
Torsional Vibration ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Tuned Mass Damper ◽  
Optimal Parameters ◽  
Lagrangian Equations ◽  
Tuning Ratio ◽  
Mass Damper

In this paper, an analytical method is presented to determine the optimal parameters of the symmetric tuned mass damper, such as the ratio between natural frequency of tuned mass damper and shaft (tuning ratio) and the ratio of the viscous coefficient of tuned mass damper (damping ratio). The optimal parameters of tuned mass damper are applied to reduce the torsional vibration of the shaft based on consideration of the vibration duration and stability criterion. The dynamic equations of the shaft are provided via Lagrangian equations, and the optimal parameters of tuned mass damper are derived by using the principle of minimum kinetic energy. Analytical and numerical examples are implemented to verify the reliability of the proposed method. The analytical and numerical results indicate that the optimal parameters of tuned mass damper have significant effects in the torsional vibration reduction of the shaft.

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