scholarly journals Test rig for rod seals contact pressure measurement

2010 ◽  
Author(s):  
G. Belforte ◽  
M. Conte ◽  
L. Mazza ◽  
T. Raparelli ◽  
C. Visconte
Keyword(s):  
Contact Pressure ◽  
Pressure Measurement ◽  
Test Rig ◽  
Rod Seals

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.

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 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 Indirect contact pressure evaluation on pneumatic rod seals

2018 ◽  
Vol 118 ◽  
pp. 240-245
Author(s):  
G. Belforte ◽  
M. Conte ◽  
A. Manuello Bertetto ◽  
L. Mazza ◽  
T. Raparelli ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Indirect Contact ◽  
Rod Seals

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

Central and Minimum Elastohydrodynamic Film Thickness at High Contact Pressure

1997 ◽  
Vol 119 (2) ◽  
pp. 291-296 ◽  
Author(s):  
M. Smeeth ◽  
H. A. Spikes
Keyword(s):  
High Pressure ◽  
Film Thickness ◽  
Contact Pressure ◽  
Applied Load ◽  
Optical Technique ◽  
Test Rig ◽  
Minimum Film Thickness ◽  
Elastohydrodynamic Film Thickness ◽  
Contact Pressures ◽  
High Contact Pressure

A new optical technique has been developed which is able to obtain accurate film thickness profiles across elastohydrodynamic (EHD) contacts. This has been used in conjunction with a high pressure EHD test rig to obtain both central and minimum EHD film thicknesses at high contact pressures up to 3.5 GPa. The results have been compared with the classical film thickness equations of Hamrock and Dowson and also with recent high pressure computations due to Venner. It is found that minimum film thickness falls more rapidly with applied load at high than at low contact pressures, with a film thickness/load exponent of −0.3. This confirms the findings of recent high pressure computational EHD modeling.

scholarly journals Experimental and Numerical Determination of Critical Buckling Pressure of thin Cylindrical Shells Subjected To External Pressure

2020 ◽  
Vol 8 (6) ◽  
pp. 4362-4366
Keyword(s):  
Cylindrical Shell ◽  
Boundary Conditions ◽  
Measurement System ◽  
Pressure Measurement ◽  
Thin Shell ◽  
External Pressure ◽  
Shell Structures ◽  
Test Rig ◽  
Critical Buckling Pressure ◽  
Pressure Measurement System

Thin shell structures have very high load bearing capacity, hence find wide applications in the field of mechanical engineering, structural engineering, sea shore structures, aerospace industries and nuclear engineering structures. The major failure of thin shell structures is buckling. Oil carrying pipelines, hull structures, oil tankers are few examples in which thin cylindrical shell structures fails by buckling under external pressure loading. In order to avoid the buckling failure, prediction of critical buckling pressure is important in thin shell structures under external pressure. But this critical buckling pressure depends on boundary conditions, imperfections, thickness variation of shells etc. To estimate the effects of these parameters on Critical Buckling Pressure (CBP) require a reliable experimental test rig. Hence in our proposed work, efforts are taken to develop a simple cost-effective reliable test rig to determine the effects of these parameter variations on the critical buckling pressure. For developing the test rig two important components to be designed properly namely, external cover cylinder and online pressure measurement system. The external cover cylinder with lid which contains test cylindrical shell inside should be designed in such a way that it should be leak proof and rigid so as to withstand the internal working pressure with negligible deformations. Hence, a ring and stinger stiffened cylindrical shell is taken as external cylindrical shell. The pressure variation in the test rig should be recorded online so as to predict the critical buckling pressure accurately. Hence, PC interfaced microcontroller-based pressure measurement system is developed in our proposed work. The test cylinder considered for this work is made of mild steel of size diameter 456 mm, length 456 mm and thickness 1 mm. The classical (simply supported) boundary conditions are assumed and simulated on both sides of the test cylinders. The experimental critical buckling pressures are compared with the FE results and both the results have good agreement

scholarly journals Test and fabrication of piezoresistive sensors for contact pressure measurement

2017 ◽  
pp. 47-52 ◽  
Author(s):  
Diego Andres Valle-Lopera ◽  
◽  
Andrés Felipe Castraño-Franco ◽  
Jonathan Gallego-Londoño ◽  
Alher Mauricio Hernández-Valdivieso ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Pressure Measurement ◽  
Piezoresistive Sensors

Qualification Method for Cut Resistant Jackets for Fiber Mooring Ropes

2021 ◽  
Author(s):  
Øystein Gabrielsen ◽  
Kjell Larsen ◽  
Svein Helge Gjøsund ◽  
Karl-Johan Reite ◽  
Kurt Eide ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Mooring Line ◽  
Mooring System ◽  
Test Bed ◽  
Test Rig ◽  
Exclusion Zone ◽  
Fishing Activity ◽  
Norwegian Sea ◽  
Fishing Vessels ◽  
Abrasion Testing

Abstract The Aasta Hansteen spar platform in the Norwegian Sea has a polyester rope mooring system. The anchors and large parts of the polyester ropes are outside of the safety exclusion zone granted by the Norwegian authorities. Fishing vessels cannot be denied as long as they are outside of the safety zone, and the polyester mooring ropes need to withstand abrasion loads from the possible fishing activity. A fishing activity study in 2013 defined probability for fishing, size of possible fishing vessels and type of fishing equipment. Numerical simulations of the mooring system and crossing fishing trawl equipment made it possible to establish trawl abrasion load cases, including trawl wire lengths, speed and contact pressure. No jacket design or jacket material was at the time confirmed to withstand the established abrasion loads. The jacket solution to be chosen for the project thus needed to be specially developed, designed, tested and approved to give sufficient resistance against the established abrasion loads. Several vendors developed and offered different jacket solutions, and the selection of cut resistant jacket was dependent on adequate testing. Based on input and comments from Equinor and rope vendors, DNV constructed a test rig extension to their 2500T horizontal test bed, where the required length of trawl wire was pulled over the polyester rope with the needed contact pressure. Full-size (diameter) ropes with the proposed cut resistant jackets were tested, including break strength testing after the abrasion test. This paper presents how the possible trawl activity was defined, the numerical simulation of trawl/mooring line interaction, the test rig setup and some test results of the trawl wire abrasion testing.

Sign in / Sign up

Export Citation Format

Share Document