Transfer of innovative technologies

Joint project of KNUCA and Zhejiang Yuexin Inspection Technology Co., Ltd.

Mykhailo Sukach, Jin Hangfei — Wed, 26 Apr 2023 00:00:00 +0300

Every year, international scientific conferences are held in China, dedicated to the search for high-class talents, the attraction of innovative technologies, the creation of joint ventures in various fields of science and production. One of the organizers of such events was the Ukrainian-Chinese Silk Road Center, which, as part of the "One Belt, One Road" program, regularly conducts online video road shows between Chinese and Ukrainian specialists. This time, projects from several branches of production, including mechanical engineering and robotics, were presented. The best works are selected for the preparation of grant applications for research funding in laboratories and research groups in China, as well as for participation in the country's production activities.

One of the successful applications was a joint project of the Kyiv National University of Civil Engineering and Architecture and the pipeline diagnostics company Zhejiang Yuexin Inspection Technology Co., Ltd. Doctor of Technical Sciences, Professor M.K. Sukach took part in it as the technical director of the project., specialist in deep-sea technology. The Chinese side was headed by the project's chief manager, company director Jin Hangfei. The project became one of those selected by the Ukrainian-Chinese Center and nominated for a state grant. He won the support of the Beijing High-Tech Exchange and government funding for joint research. In addition to the scientific component, it provides an educational program for student training, PhD training and advanced training of specialists in the relevant field.

Increasing the efficiency of trenchless laying machines using vibrating knives

Vladimir Suponyev, Vitaliy Ragulin, Volodymyr Oleksyn — Wed, 26 Apr 2023 00:00:00 +0300

Modern requirements for the laying of underground communications consist of a combination of high construction rates with low energy consumption. The highest rate of laying linear objects is ensured by knife-type cable and pipe-layers, which are designed for their trenchless burial - this is when a narrow slot is cut in the soil, through which a cable or pipeline is launched. A feature of this process is the need to use large traction forces, which are determined by the resistance forces of the soil when cutting it. Accordingly, the cutting resistance of the soil depends on the dimensions of the width and depth of the gap and the physical and mechanical properties of the soil. Finding ways to reduce forces for deep cutting of soils is an important problem.

One of the ways to improve the efficiency of trenchless laying machines is to equip them with vibrating knives. It is known that when the knife oscillates in the vertical direction, it leads, depending on the soil and the speed of movement, to a 30…60% decrease in traction resistance. But the use of more complex vibration movements of the knives allows reducing the traction resistance during deep cutting of soils by 70…90%. It is well-known that various designs of mechanical drive are used to implement the process of vibration of knives. These are complex devices that, together with the entire machine, require calculations. Therefore, studying the forced vibration of the knives of pipe deepeners is an urgent task, which is aimed at reducing the energy consumption of the process of soil deep cutting and improving the overall performance of knife machines for trenchless laying of underground utilities.

To achieve the goal, the paper considered possible variants of the vibration oscillation of the knives and provided calculation dependencies for determining the resistance of soil cutting by active knives; also the dependence for determining the maximum average drive power of a centralized unbalanced vibrator was given. At the same time, the dimensions of the gap obtained, the physical and mechanical properties of the soil and the technical characteristics of the vibrator were taken into account.The obtained recommendations can be used when designing trenchless laying machines using vibrating knives.

Silicon from sand is a promising technology for producing silicon of semiconductor quality

Tatiana Kritskaia, Mykhailo Sukach, Yevgen Bazhenov — Wed, 26 Apr 2023 00:00:00 +0300

An analysis of the methods for obtaining silicon of semiconductor quality determined the relevance of the issues of compliance of modern technologies with environmental requirements of today, as well as the possibilities of raw materials and energy supply for a potential increase in production volumes. The development of production requires a search for compromises between the needs of society and the consequences expressed in the environmental impact on nature, the growth in the consumption of raw materials and energy. The proposal to use quartz sand instead of quartzite is promising due to the solution of the problems of raw material supply for the production of silicon of semiconductor quality for many years to come. The technology of chlorination of quartz sands proposed for implementation has been tested in industrial conditions and, in addition to the problems of raw material supply, to a large extent solves the problems of environmental and energy supply.Within the framework of the set environmental task, the problems of decarbonization of production are first of all solved by eliminating the energy-consuming high-temperature process of carbothermal reduction of silicon. The proposed technological solution provides a compromise between environmental friendliness and energy efficiency by involving silicon-containing materials, technogenic wastes, as “energy donors” in physical and chemical processes. Chlorination of the prepared raw materials is carried out in the solid phase, which is an energy-efficient solution, as it eliminates the cost of energy to compensate for the latent energy of melting. The initial preparation of raw materials involves the procedure of mechanoactivation - energy-efficient activation of the raw material by destroying intercrystalline bonds. The use of “energy donors” in blending ensures that the chlorination process is carried out in the autothermal mode, reducing the specific consumption of chlorine for the process. The problems of high energy intensity in the production of silicon of semiconductor quality are also solved by adjusting the technological scheme with the exclusion of energy-consuming low-temperature processes.The implementation of the proposed technological solutions is focused on the maximum use of known technological equipment, which minimizes the costs of design and production development of the technology. Based on the practical data obtained, system solutions for integrating the new technology into the schemes of existing enterprises are proposed - providing variability of adaptation in terms of raw material supply and the range of produced polycrystalline silicon of both “electronic” and “solar” quality. Based on the practical data obtained, system solutions were proposed for integrating the new technology into the schemes of existing enterprises - providing variability of adaptation in terms of raw material supply and the range of produced polycrystalline silicon of both “electronic” and “solar” quality.

Simulation modeling of the lifting and assembly module of the supports of the structural coating

Volodymyr Rashkivskyi — Wed, 26 Apr 2023 00:00:00 +0300

The materials of the article are devoted to the issue of simulation modeling of construction mechanized technological equipment, in particular, modeling of the lifting and assembly module for the installation of a structural coating. Today, an urgent task in the construction market is the construction of large-scale structures, the life cycle of which is shortened, but the construction terms are reduced. Such a need exists in the construction of shelter hangars, field hospitals, warehouses, etc. As a rule, for urgent needs, buildings with light construction structures are erected, the covering of which is formed by structural blocks. A feature of such structures is multi-element support elements. A lifting assembly module is proposed for the installation of such structures.

It is essential that the mounted structural coating is assembled on the heads of the lifting and collecting modules in blocks, and the lifting of the structural block to the design mark occurs thanks to the module while simultaneously raising/assembling the supporting elements of the coating. Simulation computer modeling tools were used to study the possibility of implementing the assembly process using the lifting assembly module. It is proposed to use the parametric formation of sketches and 3D models when forming the design features of the module. The dissection of the elements of the new assembly module, support elements and structural coating to the level of simple parts made it possible to determine their mass characteristics with sufficient accuracy. The basic technical indicators of the assembly module and building structures, which can be used in the development of the assembly technology, were obtained.

Approaches to the use of cloud databases when using unified elements during design are defined.
The use of simulated geometric modeling data allows to analyze the strength properties of the components of the technical system and, together with the visual observation data, to create a common information model of the building object with the possibility of qualitative analysis of the indicators of the specified elements of building structures.

National politics of decentralization as town-planning process forming of the in-plant systems

Vitaliy Yatsenko — Wed, 26 Apr 2023 00:00:00 +0300

The article is a result of an analytical research on development of relations between the city and suburban area. An attempt to define main factors that may be included into a future strategy of balanced development and to avoid a number of problems in the organization of group forms of settlement in the big cities' influence zone. The decentralization processes in the governance system constitute the social and economic potential for creation of a system of common interests in development, and not for destruction of both cities and suburban area. The research materials analyze the current state of affairs of urban planning activities in Ukraine, in particular, peculiarities of regional planning, using three largest cities and their suburbs as case studies. A number of negative trends have been discovered in the relations between the city and suburban area, that need to be resolved during the subsequent stages of designing to take into account the changes in the management system – decentralization and development of territorial communities that will be interacting with the city on systemic positions.

System Design Principles: adaptation to time for long living autonomous systems

Sergii Kornieiev — Wed, 26 Apr 2023 00:00:00 +0300

The article presents the principles of creating systems with the adaptation to the operation time. In the literature on systems design the adaptation mostly concerned: 1) the unknown object structure; 2) the unknown object parameters; 3) unknown parameters of input signals; 4) the unknown functions of system state dynamics; and 5) unknown environment conditions. It usually assumed that the control process is intended to achieve a certain, usually optimal state of the system, - such way the “adaptive system concept” are close to “optimal system concept”. The other approach for system design with these conditions is robustness, as robust control does not need a priori information about the bounds on these uncertain or time-varying parameters; robust control guarantees that if the changes are within given bounds the control law need not be changed, while adaptive control is concerned with control law changing itself. In the last 10 – 15 years there was introduced the new approach as “resilient systems”. “Resilience engineering” may look like “repairing engineering” – it is assumed that errors or malfunctions occur “for sure” and the system should respond appropriately to this.

The system operation time, as the cause of adaptation, was very rare considered, mostly when reliability issues are discussing. The proposed approach is new. The proposed principles should be used with known approaches of dependable system design, – these are engineering and information theory redundancy. Both approaches must be used in the design phase and are unchanged structural parameters of the system during operations. There were concerned mostly “long-living systems” and the same task of reliability.

Proposed principles can be used in the development of the systems designed for continuous operation with absence of the possibility of external human intervention to restore system performance or some maintenance procedures. By «system» in this article are meant «Complex Adaptive Systems» (CAS). Currently, the proposed approach can be attributed to the development of "Artificial General Intelligence" (AGI). Examples of such systems include space-based and underwater-based robotic systems. By “Adaptability of the system to time” – in the sense of control process – it is meant a certain structural reconfiguration of the system, considering the non-stationary nature of stochastic processes of errors, damages, and system failures.

The formulation of principles is of a general declarative nature – at this stage the author gives preference to the essence of the proposal, rather than its formalization. The article does not provide specific design guidelines, but contains some examples of possible applications, mainly to highlight the essence of the proposals.

Problem of plane strain state of two-layer body in dynamic elastic-plastic formulation (Part III)

Vladislav Bogdanov — Wed, 26 Apr 2023 00:00:00 +0300

Composites materials are artificially created materials that consist of two or more components that differ in composition and are separated by a pronounced boundary. The development of modern composite materials is associated with the discovery of high-strength whiskers, with the study and use of aluminides and high-strength alloys. At present, various composite materials have been developed and used: fibrous; reinforced with whiskers and continuous crystals and fibres of refractory compounds and elements; dispersion-hardened materials; layered materials; alloys with directional crystallization of eutectic structures; alloys with intermetallic hardening. There are many technologies for producing composites: imbibition of reinforcing fibres with matrix (base) material; cold pressing of components followed by sintering; sediment of the matrix by plasma spraying on the hardener, followed by compression; batch diffusion welding of multilayer tapes of components; joint rolling of reinforcing elements with a matrix, and etc. The use of composites makes it possible to reduce the weight of aircraft, cars, ships, increase the efficiency of engines, and create new constructions with high performance and reliability. The development of composites with high impact resistance is an important direction in the industry. The strength characteristics of a layered composite material are decisive under shear loads, loading of the composite in directions other than the orientation of the layers, and cyclic loading. In this paper, we study the non-stationary interaction of an absolutely rigid body on a two-layer reinforced composite material. The action of the striker is replaced by a non-stationary vertical even distributed load, which changes according to a linear function, in the area of initial contact, which is assumed to be unchanged over time. In contrast to the previous articles (Parts I and II), in this papers there is an investigation of the strain-stress state, the fields of the Odquist parameter and normal stresses depending on the material of the first (upper) layer.

Problem of plane stress state of two-layer body in dynamic elastic-plastic formulation

Vladislav Bogdanov — Wed, 26 Apr 2023 00:00:00 +0300

Composite materials are widely used in industry and everyday life. Many different methods are used to calculate and develop composite materials. Many methods of calculation and design of such materials are successfully used. In this article, for the design of composite and reinforced materials, a technique for solving dynamic contact problems in more precise an elastic-plastic mathematical formulation is used. To consider the physical nonlinearity of the deformation process, the method of successive approximations is used, which makes it possible to reduce the nonlinear problem to a solution of the sequences of linear problems. The problem of a plane stress state (PStS) of a beam made from the composite reinforced double-layered material is being solved in dynamic elastic-plastic mathematical model. The reinforced or armed material consists of two layers: the upper (first) thin layer of solid steel and the lower (second) main layer of glass. This composite base is rigidly attached to an absolutely hard half-space. Rigid adhesion of the layers to each other is assumed. Glass is a very strong and very fragile material at the same time. The fragility of glass is due to the fact that there are many microcracks on the surface, and when a load is applied to the glass surface, these microcracks begin to grow and lead to the destruction of glass products. If we glue or immobilize the tops of microcracks on the surface, we will get a strong reinforced armed material that will be lighter, stronger and not subject to degradation of material properties such as aging, corrosion and creep. The impact process was modelled as a non-stationary plane stress state problem with an even distributed load in the contact area, which changes according to a linear law. The fields of the Odquist parameter and normal stresses were studied and compared to corresponding results of plane strain (PSS) problem with the same material of layers, same their thickness and size of the contact area. The upper reinforcing layer of metal or steel can be applied to the glass surface so that metal or steel atoms penetrate deeply, fill microcracks and bind their tops. The top layer can be quite thin.