Abstract: Vibrodiagnostics of metal-cutting machines is an efficient method to increase reliability of all elements of the technological system «machine tool-device-instrument-detail». The development of vibrodiagnostic methods is especially important for milling metal-cutting machines which operate in intermittent cutting mode and are exposed to shock-vibration loads. One of the trends in the development of metal cutting equipment is to increase its productivity by expanding the ranges of cutting modes. Increase in the combination of cutting modes leads to increased probability of coincidence of the natural frequencies of the equipment and the frequencies of the cutting process which in its turn leads to operation of the machine equipment elements under resonance conditions. In the article we provide the results of our research aimed to develop the method to reduce shock-vibration load on tool and peak-factor equipment of milling machine. In our research we developed the technique that makes it possible to measure not only the general level of vibration, but also other parameters used for vibrodiagnostics, for example, the value of the peak factor has been developed. The method includes the development of a principle layout and of a plan for a three-factor experiment, construction and analysis of vibrational and spectral diagrams of the milling process for the assignment of optimal modes that provide machine operating at lower level of shock-vibration loads. Based on the results of the work we have come to the conclusion that it is rather promising to use the peak factor in analysis of the milling machines reliability.
Abstract: In this paper the measurement methods for extended objects’ geometry on the basis of effect of light diffraction which can be applied to technological control of products with wide range of diameters from the smallest to the largest are described. During measurement the method that allows to minimize the influence of disturbing factors on the results of measurements of diameter of thin fibers of small diameters of micron is described. Disturbing factors include excessive flare of area of the central maximum range. The diffraction method is considered that allows to increase to units of micrometers the resolution of the optical measuring converters used in devices to perform technological control of cylindrical extended products of a large diameter such as: cables, wires, cords, etc. The transformation function allowing to calculate diameter of cylindrical products irrespective of their location in a control zone on the basis of the diffraction method of delimitation of the product shadow in optical two-coordinate converters with the dispersing laser bunch is offered and experimentally confirmed. The achieved results can be used for development of high-precision optical devices of technological control of outer diameter and eccentricity of products for cable, pipe and other products in different industry fields.
Abstract: The paper considers the mathematical model of liquid motion in straight-line capillaries. The proposed mathematical model shows the liquid motion in slit-like capillaries, with regard to the density, viscosity and surface tension of liquids, the capillary size, and the angle of capillary inclination to the horizontal. The modeling results are proved by full-scale experiments.
Abstract: The search for effective methods of management is one of the strategic directions of economic development. To obtain high-quality products, organizations should manage nonconformities and causes of product defects. The paper focuses on the analysis of groups of defects of welded joints using statistical methods. Welding process was considered as one of the processes of management. The possible causes of nonconformities were indicated. The method of failure modes and effects analysis was used to quantify the level of risk. A matrix of consequences and probabilities was presented, and critical risks and risk situations were selected. The proposed measures to eliminate or minimize negative effects enable identification of problem areas of the life cycle of welded structures.
Abstract: The paper provides a brief review of modern sources of ultraviolet (UV) radiation used in fluorescent penetrant testing (FT). The differences in implementation of the method with different radiation sources (excilamps, mercury UV lamp and LED UV lamp) are revealed experimentally. It is shown that the XeCl excilamp is not inferior to other sources of UV radiation used in FT.
Abstract: The paper describes the electro-capacitive method for monitoring wire capacitance, which is implemented using the CAP-10 device, employed for in-process testing of the single core electric wire capacitance. Focus is made on the operating principle of the CAP-10 device. The possibility of using the CAP-10 device for detecting local defects in wire insulation is proved. Insulation defects such as foreign inclusions in the form of copper shavings, air cavities inside insulation and those at the core–insulation boundary are modeled. The impact of the defect geometric parameters on the wire capacitance measured during in-process testing is investigated through numerical simulation. Mathematical simulation results are validated through the physical model using the CAP-10 device.
Abstract: The paper discusses the results of modeling of thermal radio processes for the purpose of non-destructive testing, diagnosis of dynamic states and prediction in dielectrics by sensing electromagnetic self-radiation in microwave hyperspectral mode. Measurement errors when using radiometric methods of testing have been shown. We have found the specifics of reducing measurement error while increasing the dynamics and resolution of radiometric measurements. We have presented a schematic of a new type of hyperspectrometer with higher performance and frequency resolution.