Due to today's conditions, it is necessary to reconsider the purpose of buildings and structures that use a significant number of reinforced concrete elements subjected to complex stress-strain states. The researchers are faced with the task of determining the residual bearing capacity of an element with uneven damage, which will allow choosing the most optimal option for calculating and selecting materials.
Currently, on the world market, there are trends in the construction of a large number of monolithic and prefabricated reinforced concrete structures, and individual parts of these structures are operated with damage or defects, and the causes of these damages are quite diverse. In modern conditions, such work can be facilitated and analyzed in more detail with the help of specialized software, which can include all the necessary characteristics of material behavior and include existing defects or damage.
We consider the problem of determining the stresses and strains of a two-layer body consisting of an orthotropic layer of constant thickness connected to an orthotropic half-space. The surface of the layer is subjected to known external loads, such that the deformation of the body is plane. At infinity, the stresses are zero. The stress-strain state of the body is determined using the method of integral Fourier transforms. The features of solutions of the system of differential equations of the problem are investigated. The solutions of a particular problems are ob
Machining difficult-to-cut materials, which include most high-alloy chromium-nickel steels and alloys, requires optimization of cutting parameters, correct application of tool materials, cutting blade geometry, etc. The particular relevance of a scientifically based analysis in addressing these issues is due to the large costs incurred in machining products made from such materials. The possibilities of experimental research to provide correct technological recommendations are quite limited.
Постановка проблеми. За останні десятиліття значно зросло виробництво олійних культур і продуктів їх переробки. Рослинні олії виробляють в основному пресуванням масловмісної сировини на шнекових пресах. Під час роботи преса необхідно адаптувати режими його роботи до насіння окремих культур із забезпеченням можливості коригування певних параметрів роботи, які задані технологічно. призначення.
In this article, a new method of increasing the efficiency of combined steel roof trusses is proposed and considered. A rational shape of the steel roof truss, including its topology and rational geometric parameters, was obtained, but without obtaining a rational SSS. A proposed method provides the adjustment of SSS in the truss by changing the upper belt panel length. On the basis of the obtained rational SSS of the combined truss, a new structural form is proposed.
The low machinability of titanium alloys is determined by the physical, mechanical, and chemical properties of these materials and their mechanical characteristics. It is also evident in the hardened state of the material being processed during cutting and in the initial state. This phenomenon is caused by thermodynamic parameters that determine the properties of titanium material at elevated temperatures. The peculiarities of the cutting and chip formation processes during titanium alloy machining are presented in this article.
In this article on increasing the efficiency of steel combined structures, the tasks of rational design, regulation and control of structural parameters of elements, the use of steels with increased mechanical properties are considered. It is shown that for a six-span stiffening girder of a combined truss with elastic supports, which operates under a distributed load, the moment is 72 times smaller than the moment of a single-span beam. It is suggested to use high-strength steel for truss braces. Rationality criteria are proposed.
Wide spread of RC structures in construction projects indicates the necessity of their service life prolongation. Perspective possibility to increase strength of RC structures is use of external composite tapes. The article presents theoretical research on the effectiveness of strengthening of RC bended elements with the use of composite tapes. Work also includes comparative analysis on the basis of calculations, according to normative regulations.
Heat-resistant and high-alloy steels and alloys are difficult materials to machine. Optimizing the cutting parameters for such materials is a complex and multi-factorial technological process planning task. The paper describes the method of analysis of loading, thermodynamic and stress-strain state of a workpiece while cutting of typical representative of hard-to-cut materials (chromium-nickel alloy IN718) using finite element simulation. Influence of feed rate on cutting force and temperature in the zone of chip formation is given.