http://arthra.ugal.ro/handle/20.500.14043/25512 2026-04-05T15:52:38Z http://arthra.ugal.ro/handle/20.500.14043/25539 A Study of Electromagnetic properties of Fiber Fabric Based Filled Epoxy Composites Cîrciumaru, Adrian; Bîrsan, Iulian; Andrei, Gabriel; Dima, Dumitru Electric and magnetic properties of laminate carbon fiber fabric based epoxy composites are investigated through experimental techniques. Various concentrations of powder fillers were used in order to change the basic properties of standard composite. Also effects of an electric or a magnetic external field over the mentioned properties are investigated. Characterizing the reaction of the sample to an electromagnetic wave the electric capacitance and the electric inductance of samples are investigated both across the reinforcement and at the surfaces of samples. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 1 – 2007, ISSN 1453 – 083X 2007-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/25538 Vibration Diagnosis Systems for a Cold Rolling Mill Machine Dragomir, Ștefan; Măcuță, Silviu; Spânu, Constantin In this work is shown the importance to use a monitoring by vibration system for a cold rolling mill machine. The using of this monitoring vibration system reduce maintenance costs, minimize the impact on operation because is monitoring the rolls, the backup rolls, the coupling shaft, the gears from power system. Another advantage is to preventing damage occurring by detecting signs of abnormalities. The accurate prediction of works parameters is essential for a product quality. Currently, a mathematical model is used. It is important to directly predict the roll force and the other parameters, to compute a corrective coefficient Using a mathematical model, we grove up the possibility to obtain a new quality for laminates strip. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 1 – 2007, ISSN 1453 – 083X 2007-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/25537 X-Ray Diffraction Residual Stress Measurements for Quality Control Testing Gheorghieș, Constantin; Cantaragiu, Alina-Mihaela; Stasi, Iuliana Valentina This paper present the primary difficulties which are associated with the obtaining and interpreting surface X-ray diffraction residual stress results: the surface stresses may be identical for the shoot peening, nitriding and grinding parameters; many machining and grinding metal removal processes can generate local fluctuations in the surface residual stress; for many material removal and surface treatment processes the depth of penetration of the X-ray beam is quite shallow and can cause experimental error in the measurement of the surface stress. The stress distributions by conventional and abusive grinding of 4340 steel, the surface residual stresses for 5160 steel leaf springs shot peened may prohibit the use of non-destructive surface stress measurements. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 1 – 2007, ISSN 1453 – 083X 2007-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/25536 New Welding Techology-The Cold Welding on Cogged Surfaces Georgescu, Bogdan; Georgescu, Valeriu Welding by cold pressing on cogged surfaces, produces the joint of a component made from an easy deformable metal by pressing on the cogged surface of a harder metal component. Different welds between aluminium (the easy deformable component) and copper, brass, steel, stainless steel (harder component, cogged on the contact surface) can be obtained. The weld is obtained only by deforming the aluminium component at a deformation rate of 20…30%. The weld tensile strength is up to 10% of aluminium ultimate tensile strength, better results being obtained for the shearing strength. The weld contact electric resistance is negligible, recommending the process for producing dissimilar elements used in electrotechnics. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 1 – 2007, ISSN 1453 – 083X 2007-01-01T00:00:00Z