Abstract
This paper shows that the technological preparation of production accounts for 20‒70 % of the total labor intensity of technical preparation. An important role belongs to the applied programs of finite-element modeling. However, such software packages often cannot be purchased by small-scale industrial enterprises for various reasons. Therefore, special empirical and analytical calculation models are used, which have proved to be quite effective in typical metal processing processes. Drawing a cylindrical hollow part was used as an example of the improved analytical dependence to calculate meridional tensile stresses. Existing analytical models of the process accounted for the bending moment through additional stresses. However, this approach only roughly described the deformation process. It was possible to refine the existing analytical dependences by introducing a term into the differential equilibrium equations that takes into consideration the bending moment that acts in the meridional direction when a workpiece passes the rounding on the matrix edge. Analysis of the obtained expression revealed that the bending of a workpiece gives rise to the stretching meridional stresses, which depend on the ratio of the squares of the thickness of the workpiece and the radius of the matrix rounding. The results of the estimation data from the numerical and theoretical models coincided for small values of the radius of the matrix rounding of 1‒2 mm, which confirms the adequacy of the analytical solution. In the numerical model, there is an extreme point where the tensile stresses have a minimum and, after it, begin to increase; this corresponds to the matrix rounding radius of 5 mm
Highlights
The production of a modern car is a complex, know ledge-intensive, and costly task
Technological preparation of production, in proportion to the total labor intensity of technical preparation, ranges from 20 to 70 % depending on the type of production and tends to increase when industrial production grows [1,2,3]
We have performed a critical review of the techniques for the mathematical description of the process of drawing cylindrical parts, which revealed that existing analytical models demonstrate the accuracy sufficient for engineering calculations
Summary
The production of a modern car is a complex, know ledge-intensive, and costly task. Each stage of manufacturing is accompanied by the involvement of a large number of human and material resources, which leads to a high cost of the final product. It is possible to reduce the labor intensity and duration of technological preparation of production by using the standardization and normalization of technological proces ses, unification of equipment, technological equipment, and documentation [4] These techniques relate more to large-scale and mass types of production and to a lesser extent affect single and small-scale production, the share of engineering products of which increases year in year out [5]. Even here the accuracy of mo deling depends on the skills and experience in the program of an engineering worker and does not exclude physical modeling, but only directs it in the right direction [12, 13] In this regard, the issue of refining the existing universal computational technological dependences that could reduce the time of debugging equipment is acute. The obtained formulations of such decisions form the basis of technological calculations and lead to a reduction in the time of preparation of production, which indicates the relevance of this issue
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
