http://arthra.ugal.ro/handle/20.500.14043/25281 2026-04-07T17:02:23Z 2026-04-07T17:02:23Z Tudor, Andrei Vlase, Monica http://arthra.ugal.ro/handle/20.500.14043/25296 2020-09-03T13:24:22Z 2007-01-01T00:00:00Z

Durabilyty of Friction Pairs With Functionality in Abrasive Randomly Particles Tudor, Andrei; Vlase, Monica It is shown that the abrasive particles, which penetrate in the convergent joint of friction pairs, can damage the superficial layer of surfaces. The wear caused by individual particle depends on having both a satisfactory understanding of individual interactions and a suitable procedure for combining these under circumstances when particle geometry has randomly aspects. It is evaluated the particle number in the clearance of cylindrical bearing. Wear determinist and random parameter predicted from the corresponding particle deformation models are shown. It is considered that the abrasive particles are ovoid with random variable radius and length. The random variable distributions are considered to be exponential and normal. THE ANNALS OF UNIVERSITY “DUNĂREA DE JOS “ OF GALAŢI FASCICLE VIII, 2007 (XIII), ISSN 1221-4590 TRIBOLOGY

2007-01-01T00:00:00Z Spânu, Constantin Rîpă, Minodora Ştefănescu, Ioan Deleanu, Lorena http://arthra.ugal.ro/handle/20.500.14043/25295 2020-09-03T13:24:22Z 2007-01-01T00:00:00Z

A Comparation of Standardized Methods for Lubrication Failure Determination Spânu, Constantin; Rîpă, Minodora; Ştefănescu, Ioan; Deleanu, Lorena Lubricants are used to prevent wear between moving parts and to resist to high pressure between them. There are standardized testing methods that determinate the wear of the contact pair pieces and the pressure that leads to lubrication failure. The standards present the conditions and procedure of the test and the equipment. This failure manifests at the beginning through a seizure and at the end through a welding between metallic separated parts. All these methods are used the four ball machine because of its constructive simplicity and easy utilization, in spite of its obsolete and given little correlation to the lubricant behaviour in real applications from the point of view of some researchers. In this paper the authors compare three such standards related to the use of four-ball machine, two American (ASTM D 2783, ASTM D 4172) and the Romanian one (SR EN ISO 20623:2004), this being adopted by the endorsement method of the standard EN ISO 20623:2003. THE ANNALS OF UNIVERSITY “DUNĂREA DE JOS“ OF GALAŢI FASCICLE VIII, 2007 (XIII), ISSN 1221-4590 TRIBOLOGY

2007-01-01T00:00:00Z Senatore, Adolfo Ruggiero, Alessandro Palade, Vasile Ciortan, Sorin http://arthra.ugal.ro/handle/20.500.14043/25294 2020-09-03T13:24:22Z 2007-01-01T00:00:00Z

Neural Networks Based Study of Friction Coefficient Variation in Sliding Bearings Senatore, Adolfo; Ruggiero, Alessandro; Palade, Vasile; Ciortan, Sorin The paper presents the possibility of using the neural networks approach for the analysis of friction coefficient evolution in case of sliding bearings. Several non-metallic bearing materials are investigated, both with water and emulsion as lubricant. The results show that the neural networks can be successfully used for prediction of friction coefficient evolution during bearing service. This way the working life of the bearing can be predicted with higher accuracy, leading to preventing the mechanical systems failure. THE ANNALS OF UNIVERSITY “DUNĂREA DE JOS“ OF GALAŢI FASCICLE VIII, 2007 (XIII), ISSN 1221-4590 TRIBOLOGY

2007-01-01T00:00:00Z Popoiu Păcuraru, Sandiţa Matulea, Iordan http://arthra.ugal.ro/handle/20.500.14043/25293 2020-09-03T13:24:22Z 2007-01-01T00:00:00Z

The Level of Confidence for a Ship Hull Girder Popoiu Păcuraru, Sandiţa; Matulea, Iordan Structural estimation consists in a set of activities done to certificate security and reliability of an existing ship for its residual service life. Depending on ship’s type and damages, there are alternatively evaluation approaches. In this paper it is presented the level of confidence determination for a bulk carrier ship based on approximate methods. Important information can be obtained with special attention on damage factors (corrosion, fatigue). Regarding the ship’s loads, first, it is calcu-lated the still water bending moment, then the wave-induced hull girder bending moment. Once these results being processed, it is possible to determine the structural stress of the ship for any age. The probability to overreach the admissible stress given by classification registers can be calculated, and the potential risk for structure becomes predictable. THE ANNALS OF UNIVERSITY “DUNĂREA DE JOS“ OF GALAŢI FASCICLE VIII, 2007 (XIII), ISSN 1221-4590 TRIBOLOGY

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