Vol 21, No 3 (2019)

The paper presents the results of the development and implementation of a promising system of active quality control of products for machining operations in the context of mass production of automotive vehicles.

A computer simulation of the process of pressing of bars with counterpressure, without counterpressure in the software package Deform 2D / 3D. It was found that the hot pressing of bar of high-strength aluminum alloy D16 with backpressure in comparison with hot pressing without backpressure revealed an increase in hydrostatic pressure, longitudinal, circumferential and radial normal stresses , shear stresses and as a consequence of the intensity of stresses. The boundaries of changes in longitudinal, circumferential, radial and angular deformations are significantly increased, which is associated with an increase in the plasticity of the deformable material caused by an increase in hydrostatic pressure. Backpressure at the exit of bar from the matrix channel changes the nature of the distribution of circumferential, radial and longitudinal stresses throughout the section of bar. The value of longitudinal tensile stresses in the surface layers of the bar is 31% less than when pressing without back pressure.

The article deals with the stability analysis of bull-nosed end milling of the titanium alloy workpiece. The full-discretization method for three-degree-of-freedom system is used as a basis for stability investigation. The mathematical model of this method is proposed to be modified by adding the process damping forces occurring due to regenerative chatter. The damping forces are expressed in the equations of the tool motion through the equivalent process damping coefficient which is evaluated differently depending on the part of the bull-nosed end mill geometry. Frequency response function of the end mill and tool clamp system are estimated in COMSOL Multiphysics. The modified full-discretization method stability analysis and stability lobe diagram plotting are carried out in Matlab software. Experimental investigation of vibration during the process of bull-nosed end milling on S500L 5-axis milling center is performed. The experimental and computational results are shown to be partially divergent which may be caused by several possible inaccuracies in evaluation of the cutting force coefficients and the frequency response function.

Significant successes have been achieved for dimensional, geometric and morphological (cumulative morphometric) characteristics due to the use of computer-digital image processing. Development of new, focused on modern technical means of reception of initial data, highly informative methodical means of diagnostics and estimation of characteristics of diamond powders and powders of other Superhard materials is an important and topical scientific and applied task.

This article contains information about result of estimations and modeling’s for defined static pressure error compensation law for typical air data system, installed on unmanned air vehicle drone. The problem statement: it necessary to provide flight test and post-flight data processing with performing of results to purpose definition of reference static air pressure data, without addicted errors caused by influence of object fuselage and extra forces. Wherein is necessary to give problem decision by means stock drone systems, without using additional trajectory acquiring systems. The optimization and definitions of law was performed by using the computer-aided system MathLab. Analysis of effects after using this law give confirmation, that defining and compensation erroneous static pressure data may be completed without using of expensive external systems or investigation of object in a aerodynamic duct. If stock onboard radio altitude, pressure sensors and GPS altitude with high accuracy will be used, and big number of flight data will be getted, then in expected flight conditions may be reached the descent accuracy of measuring absolutely barometric height to ±2 m.

The paper treats the issue of efficient method of the spacecraft’s components at the final stages of assembly. Measurements of large-sized structure’s surfaces were carried out by the laser coordinate-measuring system. The advantages of using a coordinate measuring system based on the laser radar over patterns are shown. The results of the measurements are presented.

The article is devoted to the development of a mathematical model for the efficiency of irradiation plants, which will allow to optimize the energy costs for plant reforestation in greenhouses, without economic losses. During the writing of the article, the work of a number of scientists conducting research in the field of studying chlorophyll, photosynthesis and processes occurring in the green leaf of the plant was analyzed. On their basis, a schematic structure of the photosynthetic apparatus of plants was created, and kinetic differential equations describing the structure and functioning of the photosynthetic chlorophyll apparatus of green plants were compiled. As a result of the work, mathematical expressions were obtained that describe the change in the concentrations of the basic substances involved in the formation of the photosynthetic apparatus and the accumulation of photosynthetic products. Solving these equations together, the characteristics of photosynthesizing objects in a dynamic mode will be obtained. The resulting system is the initial mathematical model describing the processes of utilization of radiant energy in the green leaf and the adjustment of the photosynthetic apparatus. Its optimal solution will be used in the experimental determination of the irradiation regime, which makes it possible to make maximum use of radiant energy by artificially planting plants in greenhouses.