Contact Pattern Measurement by Means of Ultrasonic Waves: Art of Present and Some Improvements of its Performance

1983 ◽  
Vol 105 (2) ◽  
pp. 237-241 ◽  
Author(s):  
Yoshimi Ito ◽  
Shuzo Itoh
Keyword(s):  
Contact Pressure ◽  
Pressure Measurement ◽  
Ultrasonic Waves ◽  
Joint Surface ◽  
Contact Pattern ◽  
Good Characteristic ◽  
Focus Type ◽  
Type Transducer

To understand the contact characteristics of a joint surface, it is necessary and indispensable to measure the contact pressure. There have, however, been very few contributions to the method of measuring the contact pressure when comparing it with other methods to detect the properties of engineering surfaces. The contact pressure measurement by means of ultrasonic waves (ultrasonic contact pressure measurement) is surely an effective method as ascertained by earlier works, and thus in this paper some improvements of its performance by using a focus type transducer have been reported, also referring to its art of the present. The measurement using a focus type transducer shows a fairly good characteristic as compared with that using a conventional transducer, especially from the aspect of the resolution ability of the contact pattern.

scholarly journals Contact pressure measurement by means of ultrasonic waves using angle probes.

1985 ◽  
Vol 51 (461) ◽  
pp. 268-272
Author(s):  
Yoshihisa MlNAKUCHI ◽  
Takashi KOIZUMI ◽  
Toshikazu SHIBUYA
Keyword(s):  
Contact Pressure ◽  
Pressure Measurement ◽  
Ultrasonic Waves

scholarly journals Contact Pressure Measurement by Means of Ultrasonic Waves Using Angle Probes

1985 ◽  
Vol 28 (243) ◽  
pp. 1859-1863 ◽  
Author(s):  
Yoshihrsa MINAKUCHI ◽  
Takashi KOIZUMI ◽  
Toshikazu SHIBUYA
Keyword(s):  
Contact Pressure ◽  
Pressure Measurement ◽  
Ultrasonic Waves

scholarly journals Linear and Nonlinear Normal Interface Stiffness in Dry Rough Surface Contact Measured Using Longitudinal Ultrasonic Waves

2021 ◽  
Vol 11 (12) ◽  
pp. 5720
Author(s):  
Saeid Taghizadeh ◽  
Robert Sean Dwyer-Joyce
Keyword(s):  
Rough Surface ◽  
Contact Pressure ◽  
Ultrasonic Wave ◽  
Bulk Material ◽  
Nonlinear Differential Equations ◽  
Small Deformation ◽  
Ultrasonic Waves ◽  
Solid Contact ◽  
Interfacial Stiffness ◽  
Linear And Nonlinear

When two rough surfaces are loaded together contact occurs at asperity peaks. An interface of solid contact regions and air gaps is formed that is less stiff than the bulk material. The stiffness of a structure thus depends on the interface conditions; this is particularly critical when high stiffness is required, for example in precision systems such as machine tool spindles. The rough surface interface can be modelled as a distributed spring. For small deformation, the spring can be assumed to be linear; whilst for large deformations the spring gets stiffer as the amount of solid contact increases. One method to measure the spring stiffness, both the linear and nonlinear aspect, is by the reflection of ultrasound. An ultrasonic wave causes a perturbation of the contact and the reflection depends on the stiffness of the interface. In most conventional applications, the ultrasonic wave is low power, deformation is small and entirely elastic, and the linear stiffness is measured. However, if a high-powered ultrasonic wave is used, this changes the geometry of the contact and induces nonlinear response. In previous studies through transmission methods were used to measure the nonlinear interfacial stiffness. This approach is inconvenient for the study of machine elements where only one side of the interface is accessible. In this study a reflection method is undertaken, and the results are compared to existing experimental work with through transmission. The variation of both linear and nonlinear interfacial stiffnesses was measured as the nominal contact pressure was increased. In both cases interfacial stiffness was expressed as nonlinear differential equations and solved to deduce the contact pressure-relative surface approach relationships. The relationships derived from linear and nonlinear measurements were similar, indicating the validity of the presented methods.

Transmission of Ultrasonic Waves Via Optical Silica Glass Fiber Doped by 7.5% of TiO2 with the Use of Power Sandwich Transducer

2011 ◽  
Vol 36 (1) ◽  
pp. 141-150 ◽  
Author(s):  
Sylwia Muc ◽  
Tadeusz Gudra
Keyword(s):  
Optical Fibre ◽  
Output Signal ◽  
Optical Waveguides ◽  
Experimental Studies ◽  
Signal Amplitude ◽  
Capacitive Sensor ◽  
Ultrasonic Waves ◽  
Sandwich Type ◽  
Type Transducer ◽  
Simultaneous Transmission

Abstract The possibility of acoustic wave propagation in optical waveguides creates new prospects for simultaneous transmission of laser beams and ultrasonic waves. Combined laser-ultrasonic technology could be useful in e.g. surgical treatment. The article presents the results of experimental studies of transmission of ultrasonic wave in optical fibres, the core of which is doped by 7.5% of TiO2, using a sandwich-type transducer. It also presents amplitude characteristics of an ultrasonic signal propagated in the optical fibre. Authors studied the effect which the length of the fibre has on the achieved output signal amplitudes. They presented the relation of the output signal amplitude from a capacitive sensor to the power applied to the sandwich-type transducer. The obtained results were compared with the results produced when using an optical fibre with a core doped by 3% of GeO2, in order to select optical fibre suitable for simultaneous transmission of ultrasonic waves and laser rays.

An In Vitro Osteotomy Method to Expose the Medial Compartment of the Human Knee

1997 ◽  
Vol 119 (4) ◽  
pp. 379-385 ◽  
Author(s):  
T. A. Martens ◽  
M. L. Hull ◽  
S. M. Howell
Keyword(s):  
Contact Pressure ◽  
Pressure Measurement ◽  
Femoral Condyle ◽  
Compressive Load ◽  
Medial Femoral Condyle ◽  
Medial Compartment ◽  
New Method ◽  
Load Bearing ◽  
Coronary Ligament

This study was conducted to validate a new in vitro method to expose the medial compartment of the knee to be used in subsequent studies aimed at examining the load bearing capabilities of medial meniscal allografts. The new method involves an osteotomy and reattachment of the medial femoral condyle. The primary hypothesis was that the new method does not alter tibio-femoral contact pressure and area. To validate this method, the baseline contact pressure of the intact medial compartment was measured using a new nondestructive procedure for inserting pressure measurement film into the intact medial hemijoint. A secondary and related hypothesis was that incising the coronary ligament, a destructive method used by previous investigators to position pressure measurement film, alters the normal tibio-femoral contact pressure. To test these hypotheses, Fuji Prescale pressure-sensitive film was used to measure both tibio-femoral contact pressure and area within the medial compartment of the (1) intact knee, (2) the knee after osteotomizing and reattaching the medial femoral condyle, and (3) the osteotomized knee with an incised coronary ligament, using seven cadaver specimens. Measurements were taken at a compressive load of approximately two times body weight with the knee in 0, 15, 30, 45 deg of flexion. No significant differences between the intact and osteotomized knee were detected. Likewise, no significant differences were observed between the osteotomized knee and the osteotomized knee with an incised coronary ligament. These results confirm the utility of the new method in exposing the medial compartment for manipulation and placement of medial meniscal allografts in future studies examining the load-bearing characteristics of meniscal allografts.

scholarly journals PPG Sensor Contact Pressure Should Be Taken Into Account for Cuff-Less Blood Pressure Measurement

2020 ◽  
Vol 67 (11) ◽  
pp. 3134-3140 ◽  
Author(s):  
Anand Chandrasekhar ◽  
Mohammad Yavarimanesh ◽  
Keerthana Natarajan ◽  
Jin-Oh Hahn ◽  
Ramakrishna Mukkamala
Keyword(s):  
Blood Pressure ◽  
Contact Pressure ◽  
Pressure Measurement ◽  
Blood Pressure Measurement

scholarly journals Contact Pressure Measurement System in Cross Wedge Rolling

2011 ◽  
Author(s):  
Philippe Mangin ◽  
Laurent Langlois ◽  
Régis Bigot ◽  
Francisco Chinesta ◽  
Yvan Chastel ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Measurement System ◽  
Pressure Measurement ◽  
Cross Wedge Rolling ◽  
Pressure Measurement System
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