Modeling is one of the most important parts of applied research, the processes for which carrying out full-scale experiments is either expensive or highly labor-intensive. The article deals with the ...problem of modeling the energy distribution at the stage of electron beam input during welding. The solution to this problem will allow not only to reduce the cost of testing the technological parameters of electron beam welding of products with new geometry or from new materials, but also to support the decision-making of the technologist when optimizing the manufacturing process of existing products. Based on the theory of thermal processes, mathematical models have been developed that consider the characteristics of the materials to be welded and the technological parameters of the electron-beam welding process. In the course of experimental studies, the energy distribution was simulated when the electron beam was introduced for structures made of two different materials with different geometries. The obtained models for calculating the temperature at the input section not only supplement the complex of existing mathematical models of the electron beam welding process, but also allow expanding their application for calculating and optimizing the welding process, taking into account the excess temperature at the electron beam input section. In the future, this will allow considering the temperature spread at the input stage and obtaining a more stable quality of the welded seam with fewer root defects.
The article describes the development of the software system for selecting the main modes of the diffusion welding technological process, with the implementation of the antifriction coatings based on ...fluoroplastics. The description of the algorithms for determining the main technological regimes from the entered necessary values of the tensile strength and wear rate, working conditions, operating temperature range, and the required composition of the material is given. The choice of the main parameters values of the technological process is made according to the maximum value of the tensile strength and the calculated value of the wear rate. According to the developed algorithm, the current values of the main parameters of the technological process are calculated. In case of insufficient strength of the joint or exceeding the value of the wear rate, the technological parameters are adjusted within the established limits or the coating material is replaced. For the decision support system in the design of technological processes, information bases were developed on the existing modes of polymeric materials diffusion welding to substrates of various types, and a database of tribotechnical information. The information database is implemented in a three-purpose software shell: 1) for entering and searching information in the database by fields, 2) for the work of an expert technologist, for linking information fields on topics, technologies, materials, 3) for work in the information mode, and in the mode of issuing an information array for process control. The constructed models and databases made it possible to create an algorithm for automating the diffusion welding process with the definition of the main modes. An algorithm for automating the selection of the diffusion welding main modes has also been developed. For the implementation of the "query generation" unit of the enlarged search algorithm, a production model of knowledge representation was used. As a result of the algorithm, an array of information is transmitted to the following modules of the algorithm. Databases were filled and logical connections of knowledge representation were established.
Comparative studies of the functional and mechanical characteristics of an alloy Ti−50.8 at % Ni with various initial structural states, as well as after aging at 430°C, 10 h have been carried out; ...the specific features of evolution of studied parameters using tensile tests in the temperature range of −196 ≤
Т
≤ +100°С were analyzed. The highest value of the strength characteristics (up to 1500 MPa), as well as the maximum difference between the dislocation yield stress and transformation yield stress (up to 1200 MPa) occurs after aging of an alloy with the initial developed dislocation substructure and amorphized volume of ~30%. The efficiency of aging of a material of the initially recrystallized structure depends on the grain size: the functional and mechanical characteristics of the fine-grain material almost do not change; in the initially coarse-grained material the studied characteristics increase significantly. The obtained regularities can be used for prediction of the set of functional and mechanical characteristics of titanium nickelide as a result of aging with various initial structures.
Abstract
The article is devoted to solving the problem of modelling the distribution of energy in the steady mode with electron beam welding with the means of ANSYS Academic Student. The authors ...propose the implementation of the simulation model to allow evaluating the density of the heat field in the assembly unit of the product when it is connected to its elements by means of electron beam welding. Two imitation models are implemented for one of the types of aerospace products, made of titanium alloy and aluminum alloy. Such models allow research to assess the effect of technological parameters of the process of electron beam welding on the heating intensity of the zone near the weld. A series of experiments with visualization of their results for various power values was carried out.
Abstract
The presented work is devoted to the study of the effect of various values of the electron beam current on the distribution of the energy cross section of the weld when conducting the ...technological process of electron-beam welding of thin-walled structures. The work is used by the simulation system of COMSOL Multiphysics, in which mathematical models of energy distribution proposed by the authors are implemented with electron beam welding. Imitation modelling was carried out for two materials widely used in the aerospace industry: titan alloy BT14 and AMG aluminum alloy. The values of the parameters for which the simulation was carried out were selected as a result of the predetermined process of optimizing the technological mode of electron beam welding for the construction under study. In the process of the research, a change in the value of the electron beam current is carried out both in less and to the large side. The article presents visualization for the three values of the parameter under study for each material, which makes it possible to judge the effectiveness of the previously formed set of optimal parameter values.
In this paper, we researched the influence of the electron beam defocus on the quality of the weld. The carried-out research was based on the theory of the thermal field using mathematical models ...developed by the authors. As a criterion of optimality, the previously developed thermal functional was used. We obtained criteria that can be used to simulate processes in electron beam welding, and to obtain more accurate modes, which is necessary to bind to power equipment. The obtained results of the criteria can be used for electron beam welding of various materials and different thicknesses.
The article presents the concept of the control intellectualization for the waveguide paths induction soldering process. This is a concept of the intelligent information system designed to support ...decision-making in control the technological process of creating permanent connections using induction heating in conditions of incomplete or unreliable information. The system should implement methods for assessing the reliability of information on process parameters, methods for estimating the magnitude of measuring tools errors and compensation methods for obtaining unreliable information, as well as methods for predicting the development of the technological process based on the analytical core of the expert system to generate a control action when measuring devices fail. The implementation of this concept will make it possible to recognize interference with measuring instruments and their failure for the further formation of sustainable process control of induction soldering.
The article considers the problem of mathematical modeling of the electron beam welding process at the stages of input and output of an electron beam. A conceptual model is proposed, developed using ...the mathematical apparatus of the thermal process theory. The models allow the calculation of the individual stages of the process that affect the formation of a welded joint in the vicinity of the "zero point". The proposed models will be used in the future and will be subjected to verification processes by comparison with the results of field experiments.
The article presents an automated installation for pipelines brazing in protective environments using the induction heating method. The types of pipe connections are considered, and the use of boxes ...to ensure the formation of a protective environment in the process of induction soldering is proposed. A diagram of a projected automated installation for induction brazing of pipelines in protective media, as well as its main technical characteristics are given. Using the proposed installation, soldering of welding of prototypes was carried out, the results of which are presented in the article.
In this research presents results of the software and algorithmic support development for an automated system of the electron-beam welding. The article describes the basic algorithms of the software, ...their purpose and implementation. The structure of the software system is given, as well as the results of its testing. The results of the study - developed software and algorithmic support - can be used in conjunction with electron-beam equipment to control the process of electron-beam welding, allowing the setting, maintenance and display of the main technological parameters of the process, as well as process control in automatic mode.
PDF
