V. V. Kotov

Choosing an Efficient Method for Forming Parts by Means of an Engineering Analysis Performed with the Use of a CAE System

The possibility of forming parts by different methods is analyzed. The formation of defects is modeled and ways are proposed for eliminating them. A conclusion is reached as to the most efficient method of making the part that is discussed.

EFFECT OF THE AVERAGE VELOCITY OF THE FREE PART OF THE SEMIFINISHED PRODUCT ON THE PROCESS OF PNEUMOTHERMAL FORMING IN THE SUPERPLASTIC REGIME

Results are presented from two experiments involving the pneumothermal forming of a cellular product of alloy OT4-1 in the superplastic regime. It was determined that the average velocity of the free part of the semifinished product must be taken into account when using a model in which the stresses depend directly on the deformation rate.

Simulation of the Behavior of Pipes with Variable Wall Thickness Under Internal Pressure

The expansion of aluminum pipes with variable wall thickness under internal pressure is simulated using ESI Virtual-Performance 2016.0 software based on the finite-element method. The convergence and accuracy of the solution is estimated by comparing with known solutions. It is established that internal pressure causes pipes with variable wall thickness to burst where the wall is the thinnest. The thinnest section of the pipe becomes even thinner, whereas the maximum wall thickness does not almost change. This increases the variation in the wall thickness, promoting the rupture of the thin wall. It is recommended to use pipes with minimum wall thickness variation to convey high-pressure fluid.

Use of Mathematical Modeling in Selecting a Heat-Treatment Regime

Optimizing the processes used to make new and existing products is an important problem in modern industry. The urgency of this matter has led to broad use of mathematical modeling to model various industrial operations, including heat treatments. However, the adequacy of the results obtained by using the finite-elements method to model physical processes is still open to debate. The goal of this article is to evaluate results from mathematical modeling performed to choose regimes for the heat treatment of low-alloy steel and an aluminum alloy and compare those results with the results of a physical experiment.

Computer Modeling, Volume Prototyping, and Non-contact Optical Scanning in an Integrated Technology for Pre-production Casting. Trial Use

This article describes the trial use of a new integrated technology for pre-production casting in sand-clay molds. Virtual modeling of the casting operation is performed, the casting is designed, and the casting regimes are determined. A master model of the casting is constructed with the use of 3D printing. Non-contact optical scanning is used to check the geometric characteristic of the plastic master model and the actual casting made from it.

Accounting for the Technological History of the Formation of a Part in Strength Calculations. Part 2

Strength calculations are performed for a new part with allowance for the forming operations used to make it. The process of accounting for the technological history of the part in such calculations is illustrated by examining the strength design of an equipment component consisting of several parts made by different forming methods.

Eliminating Wrinkling During the Forming of Parts with a Tall Convex Side by Using Wrinkle Suppressors

The feasibility of making parts by using different forming methods is analyzed. The formation of defects is modeled and methods are proposed for eliminating them. A conclusion is reached on an efficient method for making the part discussed in the article.

Pneumothermal Forming of Corrugated Structures from Sheet in the Superplastic Regime

An analysis is made of the feasibility of making two corrugated parts on trip hammers and by pneumothermal forming (PTF) in the superplastic regime. It is shown that PTF is the preferred method for making parts with corrugated elements.

Controlling thickness variation during pneumothermal forming in the superplastic regime

Results are presented from the modeling of different methods of controlling thickness fluctuations in superplastic pneumothermal forming. Recommendations are given on the use of each method and a part made of titanium alloy VT-20 is used as an example to show the thickness distribution over the part for each method.

Forming of Tee Parts by a Process That Combines Diffusion Welding and Pneumothermal Forming in the Superplastic Regime

An alternative method is described for making tees. The article discusses the main stages in the advanced method, which combines diffusion welding and pneumothermal forming in the superplastic regime. The process of superplastic pneumothermal forming is modeled and calculated results are reported. In the method, pneumothermal forming is preceded by diffusion welding.