Lavinskii D. Estimated method for evaluating the effect of electromagnetic fields on elastic-plastic deformation of equipment of technological devices

Object of research: elastic-plastic deforming of electrically conductive bodies under the action of electromagnetic fields. The purpose of the study: development of a new estimated method for analyzing the action of electromagnetic fields on the elastic-plastic deforming of composed bodies taking into account the interconnectedness of mechanical, electromagnetic and thermal fields, and applying this method to assess the structural strength of equipment of technological devices under high intensity electromagnetic fields. The main theoretical provisions of the dissertation are based on the fundamental approaches and provisions of thermodynamics of irreversible processes, macroscopic mechanics of deforming of solids and electrodynamics. Computational methods of quantitative analysis, which are accepted in the work, are a set of computational methods of the theory of elasticity, plasticity, modeling of electromagnetic and thermal fields based on the finite element method, contact interaction phenomena were taken into account by introducing layers of contact finite elements. In the dissertation the calculation method for the analysis of thermo-elastic-plastic deforming of bodies under the action of an electromagnetic field is created; the model of contact interaction taking into account electromagnetic processes and heat transfer processes is offered; a comprehensive approach to the calculated studies of the structural strength of composed magnetic-pulse processing devices and composed dies for pressing powders of refractory compounds is proposed; calculated schemes of technological devices for deforming of thin blanks and pressing of powders of refractory compounds were created, calculated researches of quantitative characteristics of electromagnetic field and stress-strain state were carried out, which allowed to estimate structural strength of devices; the generalized conclusions concerning estimations of action of an electromagnetic field on elastic-plastic deforming of technological devices and slugs at separate operations of magnetic-pulse processing of materials and recommendations concerning a choice of rational characteristics of an electromagnetic field and design parameters of devices are carried out. The novelty of scientific results is due to the development of calculation methods for estimating elastic-plastic deforming under the conditions of electromagnetic field, taking into account the contact interaction and obtaining new data for analyzing the strength of structural elements of technological equipment of pulse magnetic processing. The paper presents new formulations and calculation models for deforming analysis based on the integrated use of approaches and methods of the theory of thermoelastic plasticity, electromagnetism and heat transfer, new conditions for contact interaction of composite bodies under EMF, which allowed to create a method of quantitative analysis of mechanical, thermal and electromagnetic processes in technological systems for various purposes. New physical and mathematical models and calculation schemes of technological operations of magnetic-pulse processing aimed at correcting defects on flat workpieces, deformation of angular zones of curved thin workpieces, pressing of products from heated powders of refractory compounds have been developed. For the first time a study of the distribution of quantitative characteristics of the electromagnetic field, thermal field and stress-strain state in the elements of technological equipment of magnetic-pulse processing, estimates of the influence of external electromagnetic field on deformation processes, established new patterns in the distribution of stress-strain characteristics from operational and design parameters of technological processes. Scientific developments and practical research results were used in the implementation of research on state budget topics of the Department of Theoretical Mechanics and Dynamics and Strength of Machines NTU "KhPI", in research and educational work of the Department of Automotive Electronics of Kharkiv National Automobile and Road University, as well as in National Research Center "Kharkiv Institute of Physics and Technology" of the National Academy of Sciences of Ukraine in the implementation of research under the state program. The results of the dissertation can be used in the machine-building industry.