Methodology for Determining the Criterion for the High-Quality Formation of T-Shaped Joints by Resistance Projection Welding Using Mathematical Modeling

Resistance projection welding of various materials and alloys has become widespread in various branches of the machine-building industry due to the high productivity of the process, technological and economic parameters of manufacture of manufacture and a wide diversity of types of welded joints. Despite its widespread use, technological processes of resistance projection welding in production conditions are not always able to provide consistently high quality of welded joints. Due to the fact that the calculation of welding operation parameters is carried out according to a universal methodology based on the heat balance equation, there are no recommended parameters for different types of joints, which, as a rule, leads to an overestimation or underestimation of welding current values. Incorrectly defined parameters of projection welding lead to the appearance of a large number of defects in T-shaped joints. Mathematical modeling is one of the effective ways to improve the quality of welded joints obtained by resistance projection welding. Existing mathematical models of the projection welding process, as a rule, have significant approximations in setting important parameters of the operation from the point of view of the welding cycle, therefore, the development of a model that takes them into account is an urgent task. The paper examines the developed method of mathematical modeling of projection welding process of T-shaped joints, taking into account the phase control of the heat input power, which is used to determine the influence of energy mode parameters on displacement characteristics of movable electrode of a contact welding machine. Based on the results of mathematical modeling, recommended dependences of the parameters of resistance projection welding modes of T-shaped joints have been obtained. The model of the resistance projection welding process of T-shaped joints is implemented in the ANSYS software product. The adequacy of the developed mathematical modeling methodology has been confirmed by experimental studies of the resistance projection welding process.