OPTIMIZING TENSILE STRENGTH AT MAG WELDING PROCESS OF S235JR STEEL

The article is of an experimental nature for welding S235JR by MAG welding method. The purpose of this work is to optimize the welding parameters of MAG welding using shield two-component gas cargon 18 to achieve ultimate tensile strength. The experiment is according to central composition design and 13 experiments were made. Samples with dimensions of 100x40x4 mm were tested with a universal tension-compression machine. Statistical processing was done and a regression relationship between welding current and seam width on the maximum tensile strength was obtained.

DESIGNING A LABORATORY STAND FOR TESTING IMPACT RESISTANCE OF PLASTIC FILMS BY FREE-FALLING DART DROP ACCORDING ASTM D1709

In this article, the process of designing a laboratory stand for testing impact resistance of plastic films using free-falling dart drop method according to ASTM D1709, type A will be followed. It will be analyzed the all stages of designing-synthesis of project solutions, analysis and optimization, assessment and presentation of tasks. The purpose of the article is to create a designing basis for the variable design of impact resistance stands to be used in the design of non-standardized laboratory equipment

RESEARCH INTO 3D PRINTING LAYER ADHESION IN ABS MATERIALS

The purpose of this article is to determine the impact of the two factors – layer thickness and printing speed in the adhesion of the layers in the ABS polymer. ABS control test tubes were printed and the tensile strength of each tube was measured. By means of statistical analysis, it was determined the impact of the layer thickness and the print speed on the adhesion between the layers. The research was focused on one of the most used materials in 3D printing. It can be concluded from the obtained results that the layer thickness has the greatest impact on the adhesion

INFLUENCE OF ADDING POLYPROPYLENE(PP) INTO POLYETHYLENE(PE) ON MECHANICAL PROPERTIES OF GEOCELLS

In the article, it will be considered what is the influence of the addition of 10% PP into a polyethylene mixture compared to a mixture of polyethylene on the main mechanical characteristics of geocells - hardness, maximum tensile strength, strength of the internal structural junctions (welds). It will be analyzed the interrelationships between the measured mechanical parameters

OPTIMIZING 3D PRINTING PARAMETERS TO IMPROVE DIMENSIONAL ACCURACY

The article examines the influence of 3D printing speed and layer thickness on the accuracy of  functional dimensions of a part-eight wall prism with 5 holes-one in the centre and 4 in the periphery. For printing the samples, ABS material was used, which is one of the main materials for the production of  machines and parts. A portal measuring machine with the highest accuracy was used to effectively perform the task of measuring deviations from the size of the sample. Due to the large volume of experimental results, they were averaged to minimize error and processed using statistical processing software. An accurate regression model was obtained and the printing parameters were optimized

OPTIMIZING 3D PRINTING PARAMETERS TO IMPROVE HARDNESS AND SURFACE ROUGHNESS

The purpose of this paper is to study the factors affecting roughness and hardness of 3D printed models. Two parameters are analyzed- 3D printing speed and layer thickness. The main disadvantage of 3D printed models is their higher roughness, which depends on the printing parameters. In order to obtain parts with smoother surfaces, it is necessary to study these parameters. Based on the obtained experimental results, a regression dependence was built describing the relationship between roughness and hardness with the investigated printing parameters

RESEARCH INTO THE ACCURACY OF HOLES IN 3D PRINTING USING TAGUCHI METHOD

The article discusses the impact of two factors on the accuracy of the hole sizes - print speed and layer thickness in 3D printing. Nine samples of the ABS polymer were printed by using a 3D printer, then the impact of both of the factors on the accuracy of 3D printing of the holes was evaluated. Taguchi's method was applied with the help of DOE in Minitab to evaluate the impact of the two factors

DETERMINATION OF THE DYNAMIC MODULUS OF LINEAR DEFORMATIONS OF REINFORCED HIGHLY FILLED POLYMER CONCRETE COMPOSITES DURING CURING

The objects of this study are reinforced polymer concrete composites with epoxy matrix and mineral dispersion fillers. Dynamic modulus of linear deformations has been measured according the standardized dynamic testing method ASTM E1876 - 02. The quantitative values of the modulus are obtained by the action of longitudinal and bending. After statistical processing of the obtained results has been established the influence of fiber in the composition on the dynamic characteristic.