Căutare 2008 fascicula8 după Titlu
Afișează articolele 20-35 of 35
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New Test Facility for Fluid Film Journal Bearings
(Universitatea ”Dunărea de Jos” din Galați, 2008)This paper describes a new experimental rig to test journal fluid film bearings. It has been operating at the NASA Glenn Research Center (GRC) in Cleveland, Ohio since August 2006. The rig can apply total radial loads of ... -
Nitrogen Influence on Indentation Fracture Toughness of Stainless Steel Coatings
(Universitatea ”Dunărea de Jos” din Galați, 2008)This paper studies some aspects of coatings fracture theory and the possibility of extending Lawn’s equation from Vickers indenter geometry to the Rockwell one. Indentation tests were performed on stainless steel coatings ... -
On Tribological Behaviour of Thermo-Chemical Treated Steels after Thermo-Magnetic Treatments
(Universitatea ”Dunărea de Jos” din Galați, 2008)The paper presents an analysis on two grades of steel, subjected to nitrocarburized or nitrided thermo-chemical treatment after different thermomagnetic treatments. Based on the concept of tribosystem, pairs of steel rollers ... -
Research Rearding of Composite Materials under the Influence of Abrasive Wear
(Universitatea ”Dunărea de Jos” din Galați, 2008)The method described in the paper will allow estimating the composite materials performances with different structures and various working conditions, with a view to estimate useful life of technological equipments parts ... -
Residual Stresses Effect on Fatigue Life of Rolling Contacts
(Universitatea ”Dunărea de Jos” din Galați, 2008)The fatigue life tests carried out on two groups of ball bearings point out the positive influence of the compressive residual stresses induced by a previous loading in the elastic-plastic domain. The values of residual ... -
Seizure of a High-Speed Three-Wave Journal Bearing
(Universitatea ”Dunărea de Jos” din Galați, 2008)This paper is focused on the geometry and operating parameters of the bearing experimentally studied at NASA Glenn Research Center by F. Dimofte. It presents two simple thermoelastohydrodynamic (TEHD) models for two typical ... -
Shear Stability as Oils’ Performance Indicator
(Universitatea ”Dunărea de Jos” din Galați, 2008)The paper presents a comparative analysis between the shear stability tests results and four ball tests results for some industrial oils. This correlation is used for establishing the way how the mechanical solicitations ... -
Some Aspects about Driving Wheel/Rail Contact in Steady State Interaction
(Universitatea ”Dunărea de Jos” din Galați, 2008)The driving wheel/rail steady state interaction and the response to harmonic excitation were studied using a complex model for track. The starting point for numerical simulations is the Green matrix of the track. The ... -
Study of Wear Evolution for a Hydraulic Oil Using a Four Ball Tester
(Universitatea ”Dunărea de Jos” din Galați, 2008)Time is crucial for the wear of materials. Time of an experiment must be long enough to obtain an observable wear but no so long to make the experiments expensive. For determining anti-wear properties of the hydraulic oils ... -
Test-Rig for Pressure Measurements in an Aerostatic Bearing
(Universitatea ”Dunărea de Jos” din Galați, 2008)The paper presents a test rig for local pressure investigation in an aerostatic or gasostatic bearing system. Using a simple and performant computer assisted measurement device, pressure evolution in lubrication area can ... -
The Effect of Wiberg Angle on the Contact Pressure Pistribution in Natural and Artficial Joint
(Universitatea ”Dunărea de Jos” din Galați, 2008)The analogies and differences between the mechanical joints and the biological ones, in the presence of relative motion, are based on the pressure distribution. The paper analysed a numerical model of the pressure distribution ... -
The Influence of the Applied Load on the Friction Coefficient of the Sintered Iron-Base Bearings
(Universitatea ”Dunărea de Jos” din Galați, 2008)In the recent years the iron base sintered bearings production was considerable increased at the expense of the copper based ones, due to the low cost and availability of the iron powders as well as the higher strength. ... -
The Tool to Model through Micro Strain and Micro Cutting
(Universitatea ”Dunărea de Jos” din Galați, 2008)The cutter wear is analised by a single hard fixed particle (inclusion) in brittle material. The shakedown pressure of the inclusion contact is directly proportional to shear field stress of the cutter surface and is ... -
Vegetal Oils as Lubricating Materials
(Universitatea ”Dunărea de Jos” din Galați, 2008)The success of vegetal oils is related to their biodegradability and reduced toxicity but a wide use is limited by their insufficient stability in time. Biodegradable oils have ecological advantages, being comparable or ... -
Viscosity of Amorphous Molecular Substances
(Universitatea ”Dunărea de Jos” din Galați, 2008)Because the great majority of flow units in a liquid behave instantaneously in a solid-like manner, rheological properties of molecular liquids subjected to high pressures may be measured by using corresponding molecular ... -
Wear Behaviour of the AL7175 Alloy under Different Bulk Stress States
(Universitatea ”Dunărea de Jos” din Galați, 2008)In what concerns the stresses involved in the process, most wear tests (namely those in the pin on disc and the pin on plate configurations) are usually solely concerned with the stress state in the contact originated by ...