In this paper, the stress and strain analysis of common laminated wood seat shell is performed. Experimental stiffness evaluation is conducted by measuring displacement of the point on the backrest, and experimental stress analysis is carried out by tensometric measuring at the critical transition area from the seat to the backrest. Finite element analysis is carried out layer by layer with a “2D linear elastic model” for orthotropic materials. Good matching is found between numerical and experimental results of displacement. It is also shown that the results of the principal stress in the measurement points of the seat shell compare favourably with experimental data. The applied in-plane stress analysis of each individual veneer is not applicable for interlaminar stress calculations that are a significant factor in curved forms of laminated wood. Curved forms of laminated wood products require more complex numerical analysis, but the method can be used to achieve approximate data in early phase of product design.

Abstract Pulse-reverse power modes are used in galvanotechniques in order to obtain coatings with better characteristics in terms of gloss, adhesion, tracking sharp edges and uniform distribution of deposits on complex shape objects, compared with the coatings produced by constant current modes. Pulse-reverse modes also allow the use of a higher current density, and thus the production speed of electroplating cells increases. Systems for standard electroplating of copper, silver and gold are optimised by the suitable choice of duration and intensity of the pulses. It is shown that coatings with satisfactory quality can be deposited using higher current density, different modes of pulsed current in a very short period of time, without expensive and often dangerous additives in the electrolyte. Parameters of the model for certain electrochemical systems were determined by modelling and computer simulation, so the system behaviour under different circumstances becomes predictive.

Mechanical shock of zircon based ceramic induced by cavitation erosion testing was investigated in this study. Several parameters were followed in order to determine level of material degradation during the cavitation erosion testing. Mass loss was taken as a conventional criterion for material degradation, while the level of surface degradation was evaluated by image and thermal imaging analyses. Results show high cavitation resistance of zircon ceramics and their suitability when vigorous cavitation erosion environment is expected.

1 University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Belgrade, Serbia 2 Prydniprovsk State Academy of Civil Engineering and Architecture, Dnipropetrovsk, Ukraine 3 University of Zenica, Faculty of Metallurgy and Material Science, Zenica, Bosnia and Herzegovina 4 University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia 5 University of Belgrade, Technical Faculty in Bor, Bor, Serbia * E-mail: zstevic@tfbor.bg.ac.rs

In this paper the ability of three natural zeolites from different localities (Vranjska banja-VB, Igros-I and Baia Mare-BM deposits) to remove copper has been investigated. These three zeolites were subjected to the elementary analysis as well as XRDP and DTA/TG analysis due to complete characterization. Cation exchange capacity of VB, I and BM zeolites were 150.1, 169.2, and 176.5 meq/100g. The maximum adsorption capacity for the copper adsorption on VB, I and BM-zeolites were 7.75, 8.51, and 11.18 mg/g. Based on the obtained results the mathematical expression that describes correlation between the CEC and copper adsorption capacity has been developed. This linear dependance has been tested with the vast variety of experimental results. According to this expression it is possible to predict the copper adsorption capacity for different zeolites based only on their CEC value.