Experimental and mathematical modelling of grain material velocity

The present article represents the next stage in the cycle of work on the research of vibrating motion of grain material. This paper contains the experimental results of the operation of a vibrating conveying machine. The investigation was carried out in three stages. The purpose of the first full-factor experiment with four varying factors was to identify factors having the least impact on the time of movement of grain material. As a result, it was found that the angle of vibration direction that has an impact on the amplitude has almost no effect on the velocity of the grain material. In the second phase of experiment carried out with three varying factors at fixed angle of vibration direction, the equation of mathematical model of time of passage of the control area has been obtained. Moreover, on the basis of previous studies, the angle of vibration direction was fixed at the position which has the greatest influence on the vibration amplitude. The third stage of the experiment was to evaluate applicability of the obtained model equation to describe movement of other grain crops with ellipsoidal grain shape. Verification of the obtained model for adequacy using Fisher's criterion showed that with 95% probability the obtained equation can be used for estimation of movement of grain material having ellipsoidal shape on vibrating surface

A research review on coarse grain micronization

This article gives an overview of research on grain micronization and the principal research areas that have been carried out in this respect. The results of the effects of infrared radiation on fodder grain used in animal feeding are presented. It is stated in most of the researches that micronization causes destruction of grain molecular structure, decreasing its hardness, partially changing amount of starch, which positively influences on absorption of grain treated by infra-red irradiation. The main lines of research into the micronization process are formulated

Modelling and calculation of stumulated oscillation for a crushing plant with vibration

The paper presents the results of the mathematical modelling of external stimuli to improve the efficiency of the removal of grain material from the grinding zone. Thus, the authors proposed to improve the evacuation conditions of the finished product from the working chamber of the crushing plant, as one of these solutions to improve the grinding process in crushers. As a result of creation of external vibrating influence. For this purpose, the calculation chart for modelling the proceeding process of the crushing plant body movement is created which takes into account weight and sizes of the crusher, weight, angular velocity of rotation and eccentric piece location, as well as rigidity of an elastic suspension on which the crusher is established. For the solution of the posed problem, we used methods of analytical mechanics, the Lagrange equation of the second kind, for the mechanical system with two degrees of freedom. As a result of calculations amplitude-frequency characteristics of mechanical system are determined. The conclusion about the choice of the angular velocity of the eccentric rotation for creation of necessary external stimulating influence on the crushing system and improvement of conditions of evacuation of a ready product from a working zone is given. The resonance frequencies of firstand second-order system vibrations and the vibrator frequency are determined to achieve resonance frequencies. Keywords: vibration, modelling, Lagrangian equations of the second kind, grinding, crushing plant

Gas Metal Arc Welding Modes in Wire Arc Additive Manufacturing of Ti-6Al-4V

In wire arc additive manufacturing of Ti-alloy parts (Ti-WAAM) gas metal arc welding (GMAW) can be applied for complex parts printing. However, due to the specific properties of Ti, GMAW of Ti-alloys is complicated. In this work, three different types of metal transfer modes during Ti-WAAM were investigated: Cold Metal Transfer, controlled short circuiting metal transfer, and self-regulated metal transfer at a direct current with a negative electrode. Metal transfer modes were studied using captured waveform and high-speed video analysis. Using these modes, three walls were manufactured; the geometry preservation stability was estimated and compared using effective wall width calculation, the microstructure was analyzed using optical microscopy. Transfer process data showed that arc wandering depends not only on cathode spot instabilities, but also on anode processing properties. Microstructure analysis showed that each produced wall consists of phases and structures inherent for Ti-WAAM. α-basketweave in the center of and α-colony on the grain boundary of epitaxially grown β-grains were found with heat affected zone bands along the height of the walls, so that the microstructure did not depend on metal transfer dramatically. However, the geometry preservation stability was higher in the wall, produced with controlled short circuiting metal transfer

Metallurgical and Mechanical Characterization of High-Speed Friction Stir Welded AA 6082-T6 Aluminum Alloy

The objective of this study was to investigate the effect of the high welding speed on the mechanical properties and their relations to microstructural characteristics of butt friction stir welded joints with the use of 6082-T6 aluminum alloy. The aluminum sheets of 2.0 mm thick were friction stir welded at low (conventional FSW) and high welding speeds (HSFSW) of 200 and 2500 mm/min, respectively. The grain size in the nugget zone (NZ) was decreased; the width of the softened region was narrowed down as well as the lowest microhardness value located in the heat-affected zone (HAZ) was enhanced by HSFSW. The increasing welding speed resulted in the higher ultimate tensile strength and lower elongation, but it had a slight influence on the yield strength. The differences in mechanical properties were explained by analysis of microstructural changes and tensile fracture surfaces of the welded joints, supported by the results of the numerical simulation of the temperature distribution and material flow. The fracture of the conventional FSW joint occurred in the HAZ, the weakest weld region, while all HSFSW joints raptured in the NZ. This demonstrated that both structural characteristics and microhardness distribution influenced the actual fracture locations

Prospects for the use of microwave energy in grain crop seeding

This study looks at determining the main trends in the application of microwaves on plants in agricultural production in the processing of grain material, it provides examples of their effectiveness and an overview of the use of microwaves on plants available on the Russian market. Additionally, the research studied the experience and developments of leading scientists in the field of microwave radiation. Analysis of the available sources provided information on the positive effect of microwave radiation in the processing of crops. The use of microwaves on plants during drying destroys pathogens and bacteria, in particular, microwave processing of red lentils reduces grey mould damage by up to 30%. Positive results are also noted in the microwave processing of other crops, providing an increase in germination capacity of up to 7% and yield growth of up to 6%. The microwave plant market in Russia is represented mainly by dryers, and the use of microwaves on plants combining several functions of drying, disinfection, and pre-sowing stimulation