Search

The reliability of the products, determined by measuring and estimating quality characteristics, plays a decisive role in the strategy of the economic evolution. In the execution of rigid road clothing, traditional materials are used, which are found in nature (stone, sand, cover aggregate etc.). Blended with binders, the resulting structures must respect specific wellestablished resistors, obtained in special production stations. In order to determine the quality of any material used in practice, first of all, it is necessary to run tests on it in laboratories equipped with specific apparatus. This paper presents a comparative study on the bending behaviour of the road concrete class BcR-4.5 and BcR-5.0, on the KD-KL 300/R hydraulic dual piston test machine. The bending strength was calculated, under the action of different forces, comparing the experimental values with the values obtained from a finite element analysis. [ABSTRACT FROM AUTHOR]

Dimensional accuracy of the cast parts strongly depends on cooling history which is mainly related with casting parameters. Cooling history refers also to heat transfer coefficient through cast/mold interface. This is a very difficult task for researchers to deal with, considering the difficulty in estimating and controlling the heat quantity which crosses the interface and mold wall going to ambient. The paper presents the estimation of heat transfer coefficient evolution during solidification of a hollow cylinder cast part. Artificial neural networks are very useful and reliable tools in prediction and estimation of casting parameters. Even if there are many previous relevant studies concerning the heat transfer coefficient determination at the cast/mold interface, researchers still deal with many uncertainties related to application of numerical developed models to a variety of dimensions and geometry. [ABSTRACT FROM AUTHOR]

Hydraulic cylinders are subassemblies of hydrostatic equipment which convert the hydrostatic energy to mechanical energy. This is possible by transforming the hydraulic parameters such as pressure and flow of the incoming fluid to parameters associated with translation, force and speed. The hydraulic cylinders usually have, as active element, a subassembly composed from a rod and one or more pistons which translates inside a working cylinder. This paper presents the functioning analysis at parallel hydraulic coupling of 3 single-rod double-acting hydraulic cylinders with different diameters and strokes. This is made in order to calculate the corresponding forces and speeds for both displacement directions of rod-piston subassembly. [ABSTRACT FROM AUTHOR]