M. I. Poksevatkin, D. I. Baklanov, S. V. German (Altai State Technical University (ASTU), Barnaul)
Streamlining assembly of workpieces by plastic deformation on the basis of ensuring the strength and rigidity of structures of composite core products
The modeling of the workpiece assembly process by plastic deformation and the rationalization of the volumes of the initial workpieces based on the required strength and rigidity of the structures of composite core products were carried out. An algorithm for constructing a modular structure of the stamping technology of a composite core product using a bank of target modules has been developed.
Keywords: modeling; rationalization; composite core product; strength and stiffness of the composite product; bank of target modules; stamping algorithm of a composite product.
A. E. Tsibulko, E. A. Romanenko (PJSC «NKZM», Kramatorsk, Ukraine)
Variants of strength criteria for ductile materials in a brittle state based on full stresses
The article suggests hypotheses on the strength of ductile materials in a brittle state based on full stresses.
Keywords: strength; separation; shear; normal, tangent, total, equivalent stresses; ball tensor.
M. I. Zemtsov, S. A. Smertin (FGBOU VО «Vyatka State University», Kirov)
Research and intensification of technology of production of thin-walled steeply bent items
One presents results of intensification of initial stages of technology of production of thin-walled steeply bent items; one gives results of researches of the final stage of the offered technology.
Keywords: thin-walled detail; cross section; bending by running with a gap; preliminary and final deformations; electrohydroimpulse stamping.
B. N. Mar’yn, N. B. Barsukov, O. E. Sysoev, S. B. Mar’yn, I. N. Ivanov (Komsomolsk-on-Amur State Technical University, Komsomolsk-on-Amur)
Development and research of the process of deformation of pipe ends with a diameter of 5–10 mm for welding them with the main pipeline
In addition to piping operating loads (pressure, vibration, temperature, etc.) face additional burden due to the mounting stresses. Mounting stresses occur in the result of derivatives of deviations from the norms of manufacturing precision parts and precision location of the locations (from the deformation of the structure).The mounting tension arising from the installation of pipes to the product is characterized by production deviations in the length in the area mates with the fitting and the eccentricity between the axes of the pipe and fitting.
To reduce mounting stresses in detachable and non-detachable connections mounting of workpieces depending on the stiffness characteristics should be considered compensation the capabilities of both the pipe and joints pipe ends. Reviewed schematics to check the strength and tightness of mounting workpieces.
Keywords: welded joints; the mounting of the workpieces; permanent connection; the mounting tension; strength; tightness.
Nguyen Chung Kien, V. I. Polkin (The National University of Science and Technology «MISiS», Moscow)
Physical modeling of the stamping process of VT6 titanium alloy endoprostheses
The article presents the results of physical modeling of the process of hot forging of forgings of a titanium endoprosthesis in open dies to select a rational pattern of forming and types of workpieces. The data obtained as a result of physical modeling are also used to select the necessary equipment for stamping endoprostheses from VT6 alloy.
To verify the reliability of simulation results and reduce the cost of developing a tool, physical modeling was carried out on a model material in laboratory conditions.
According to the drawings and a typical part of the endoprosthesis, a computer model of the process of stamping the endoprosthesis is obtained. Based on computer models, a die tooling from MDF was created for physical modeling of the process of stamping an endoprosthesis of two types: single and twin forgings. Physical modeling of the process using three types of initial blanks: cylindrical, triangular and rectangular, made of a model material - thermoplastic. The analysis of the results for the selection of the types of blanks and rational stamping scheme.
To confirm the results of computer simulation, physical modeling was carried out on workpieces from model materials such as plasticine and thermoplastics. From the above studies, it follows that the rheological properties of these materials at room temperature are similar to the properties of two-phase titanium alloys during hot pressure treatment. Both of them can be considered as viscoplastic media with significant high-speed hardening (m = 0,1...0,2) of the yield stress and the absence of strain hardening (n = 0).
In physical modeling, the task of determining the stamping force regime is not set, but only the shape change of the workpiece in open dies and the engraving filling with a complex flow of model material in the place of registration of the side inclined boss forgings of the endoprosthesis are evaluated.
Keywords: physical modeling; endoprosthesis; stamping; VT6 alloy.