Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Hydrogen Embrittlement Control of Metallic Screws after the Surface Treatments by Wedge Test

Bezecný J., Šišáková J., Bakošová D.

Machine Dynamics Research

2010

Vol. 34, No. 3

21-28

By surface treatments can occur so called hydrogen embrittlement, which is proving the cracking of joining pieces. Embrittlement on the critical value is predicated by several factors and therefore is important the concretization to admit the effective curative proceeding. Most parts produced of construction steels are exposed not only the mechanical straining but also the action of aggressive environment during its service. Common used protection is the galvanic metallization. However it impending degradation dangerous of useful properties so called hydrogen embrittlement by the surface treatments. By this time doesn't exist the definitive explanation what mechanism causes the hydrogen degradation of useful properties. At the same time is not achieved the efficiency of technologically precautions the eliminated the possibly degradation of useful properties parts influenced by hydrogen. The purpose of this paper was to verify and practically realized the method of steel hydrogenization control after the heat treatment according to ISO/DIS 10587. The test apparatus comprise of the steel wedge by angle of 6° and the filling steel plate. The test consists of screw tightening on moment, its cracks controlling and observing of number of hours leading to fracture. The experimental confirmed that the method of inclined wedge is an applicable method for material hydrogenization process on the critical value. The advantage is for state if the screws of same production runs are applicable by this standard, there can be fitted into a processing. By materials tests were occurred that for hydrogen process on critical value has the most influence the bating process realized before the surface treatments. However, after this operation is impossible the dehydrogenization of parts. The meaningful influence has also the radiuses in the critical parts which can affect as the notches and stress raisers.

Computing Simulation of Dynamical Behavior of Rectangular thin Plates and its Comparison with Experimental Investigation Obtained by Holographic Interferometry

Rusnáková S., Slabeycius J., Koštial P., Bakošová D., Švecová Z., Vavro J.

Machine Dynamics Problems

2004

Vol. 28, No. 4

89-94

In this study, experimental investigation vibration behavior of square composite plate by electronic speckle pattern interferometry (ESPI) is employed. Resonant frequencies and corresponding mode shape are obtained experimentally using the present method. The numerical calculations by the finite element method (Cosmos) are performed and the results are compared with the experimental measurements. Good agreement is obtained for both results of resonant frequencies and mode shapes. Theory of plate vibrations allows us to determine Poisson's ratio v, Young's modulus E and shear modulus G from the measured resonant frequencies.