Recent advancements in soft pneumatic robot research have demonstrated these robots' capability to interact with the environment and humans in various ways. Their ability to move over rough terrain and grasp objects of irregular shape, regardless of position, has garnered significant interest in developing new pneumatic soft robots. Integrating industrial design with related technologies holds great promise for the future, potentially bringing about a new lifestyle and revolutionizing the industry. As robots become increasingly practical, there is a growing need for sensitivity, robustness, and efficiency improvements. It is anticipated that the development of these intelligent pneumatic soft robots will play a critical role in serving the needs of society and production shortly. The present article is concerned with developing a system for monitoring a pneumatic robot's parameters, including a spatial coordinate system. The focus is on utilizing the relationship between the coordinates and pressure to model the movement of the soft robot within the MATLAB simulation environment.

Technological equipment design based on functionally modular methods is widely used in various technical fields. The designed object can be a technological machine, a production line, or a manufacturing complex. Special attention is paid to the optimization of its structure. The sequence of performing all stages of the optimization synthesis problem is presented in the article. To find a solution to this task, the developer should apply the complete or directed search of acceptable structure options and determine the best one using some optimization criteria to evaluate their quality. It can be simple enough if the designed technical system structure consists of no more than several elements. For example, if the number of alternative elements options is several dozen, it takes much time to accomplish the search correctly. Thus, the greater the number of components considered, the more difficult it is to do all the necessary calculations manually. In this case, machine resources should be involved. This scientific work aims to identify procedures of optimization synthesis that can be automated. Also, appropriate software has to be developed. Our computer program is based on the algorithm of a complete search of all options of the technical system structure. It can process an extensive array of input data and produce all possible and logically permissible results in the form the designer can analyze using the Pareto method to choose the best one. This software can be used for any technical system with a modular structure.

The formation of waviness on the working surfaces of bearing parts is associated with fluctuations in the size of the cut layer of metal and changes in the components of the cutting force. Laplace operators were used to model the centerless grinding system based on the construction of the transfer function and the characteristic equation. It was found that the formation of waviness depends on the position of the hodograph of the movement of the vector of the center of the part in the complex plane, which in turn depends on the geometric parameters of the rigid supports of the centerless grinder machine. This makes it possible, based on hodographs and the angular orientation of their asymptotes, to determine the geometric stability of the process depending on the angles of adjustment of the rigid supports of the grinder machine. Two methodological approaches were used to confirm the correctness of the hypotheses. The first one is a multiplication of wave's hodographs. The second one is regeneration displacement and the coincidence of the combined hodograph of regeneration and waviness displacement mechanisms with the hodograph of infinitely rigid machine displacement. The diagrams which allow choosing geometry of adjustment of rigid support that allows to increase or decrease parameters of certain harmonics are developed. The 3D diagram allows setting the local minima, characterized by acceptable geometric adjustment conditions, providing regulated waviness of the working surfaces of bearing parts.

The article shows the influence of the technological system of an automated lathe, in particular cam chucks, on the accuracy of machining bearing rings for production conditions. The value of the deformation during machining, i.e., the non-circularity of the ring of a single row tapered roller bearing 32017X in outer diameter, was investigated. For the study, samples were selected that were processed under the same conditions directly in the production unit of PJSC "SKF Ukraine" without interference with the technological process. The use of replaceable floating cams in the chuck design was proposed to increase the accuracy and productivity of machining. Experimental studies have shown that the machined surface's ovality depends on the chuck cams' clamping force. The effectiveness of computer processing of statistical data on the accuracy control of engineering products was shown. Implementing machining accuracy control in production using the Minitab computer program was presented. It was proven that the quality of products is formed under the influence of the use of modern computer technologies at all stages of manufacturing and control of parts, which ensures research in a wide range of changes in technological parameters and comparison of individual studies with actual machining conditions on the machine, with the results of a sufficient level of reliability.

In manufacturing high-precision rolling bearings for aviation and urban machinery, the key tasks are to reduce the cost of production of such products, increase their efficiency and resource, and ensure their reuse after performing appropriate repair work. The results of many years of research show that these tasks can be successfully solved by cleaning the working surfaces of the parts of such precision tribonodes by non-contact pulse methods, particularly by using variable electromagnetic fields. The article describes the process of deep cleaning the working surfaces of parts of various high-precision ball bearings (from overall to miniature). During this cleaning, ferromagnetic and other impurities in the form of micro-, sub-micro- and nanoparticles were removed on a developed stand that can be used on an industrial scale. Further studies of cleaned bearings showed improved operational parameters such as reduced noise and vibration and the degree of magnetization. To achieve the specified results, appropriate cleaning methods were developed and tested.

Індекс рубрикатора НБУВ: Л719.93

Рубрики:

Радіаційно стійкі пластмаси

Шифр НБУВ: Ж101239 Пошук видання у каталогах НБУВ 

A comparative evaluation of the structuring processes of the epoxy polymer system with epoxy polymers modified with polyvinyl chloride solution and epoxy composites filled with finely dispersed titanium oxide powder was carried out. Analysis of the infrared (IR) absorption spectra of the studied epoxy polymer and epoxy composite materials showed the presence of deformation and valence vibrations of certain groups of atoms. The oscillations of groups of atoms with double bonds and regions of existence of triple bonds were also revealed. In the region of high frequencies, absorption bands correspond to valence vibrations of groups containing a hydrogen atom. The presence of triple bonds in the epoxy polymer system was determined, indicating unreacted functional groups. This fact corresponds to the low content of the gel fraction of unmodified epoxy polymers after heat treatment and indicates the formation of a system with insufficient chemical bonds. The absorption bands of the epoxy composite material filled with titanium oxide powder are characterized by a lower optical density and a larger peak area compared to the bands of the unmodified epoxy polymer, which indicates the formation of a higher number of crosslinking nodes of the epoxy composite material. The introduction of polyvinyl chloride into the composition of the epoxy polymer system increases the degree of structuring of epoxy polymers. However, a smaller number of formed chemical bonds of the modified epoxy polymer was recorded compared to epoxy composites containing titanium oxide particles. The highest degree of structuring is provided in polyvinyl chloride-modified epoxy composites containing titanium oxide powder due to intensive structuring and formation of double and triple bonds.

Carbon fiber reinforced plastic (CFRP) composite materials have favorable mechanical and physical properties such as low density, high strength-to-weight ratio, high fatigue resistance and high creep behavior, and high stiffness. Thanks to these unique properties, they produce aircraft parts such as outer flaps, carry-through structures, and center wing boxes and automotive parts such as body panels, engine components, and structure members. However, studies have been continuously performed on improving the properties of CFRP composite materials. Recently, investigation of the effects of cryogenic (LN2) cooling on the mechanical behavior and characteristic of these composite materials is getting a popular and important issue. In this sense, this study aims to examine the buckling behaviors of adhesively bonded beam-produced cryogenically treated carbon fiber reinforced plastic (Cryo-CFRP), CFRP, steel, and aluminum. Therefore, a new finite element model was adopted to evaluate the buckling capacity of Cryo-CFRP composite material in the adhesively bonded beam. The model is a supported adhesive beam subject to two opposite-edge compressions until the material buckles. The elastic, homogeneous adhesive was used in the assembly. Finite element models for the adhesively bonded beam having four different adherents (CRFP, Cryo-CFRP, steel, and aluminum) were established by ANSYS(r) software. The critical buckling loads of the adhesively bonded beam were predicted, and their mode shapes were presented for the first six modes. The effects of the usage of Cryo-CFRP on the critical buckling load were investigated. Among the adherents' materials, the highest critical buckling load was determined for Cryo-CFRP/Steel adhesively bonded beam as 23,6 N. This value was obtained as 22,3 N for CFRP/Steel adherent samples. Thus, the critical buckling load was increased by 5,6 % when one adherent steel was constant and the other adherent material changed from CFRP to Cryo-CFRP. Also, the critical buckling load increased by 3,7 % when using a cryogenically treated Cryo-CFRP/Aluminum couple instead of a CFRP/Aluminum couple in the sandwich beam. The findings demonstrated that the cryogenic treatment positively affects the buckling behavior in the adhesively bonded beam.

Non-stationary loading of a mechanical system consisting of a hinged beam and additional support installed in the beam span was studied using a model of the beam deformation based on the Timoshenko hypothesis with considering rotatory inertia and shear. The system of partial differential equations describing the beam deformation was solved by expanding the unknown functions in the Fourier series with subsequent application of the integral Laplace transform. The additional support was assumed to be realistic rather than rigid. Thus it has linearly elastic, viscous, and inertial components. This means that the effect of a part of the support vibrating with the beam was considered such that their displacements coincide. The beam and additional support reaction were replaced by an unknown concentrated external force applied to the beam. This unknown reaction was assumed to be time-dependent. The time law was determined by solving the first kind of Volterra integral equation. The methodology of deriving the integral equation for the unknown reaction was explained. Analytic formulae and results of computations for specific numerical parameters were given. The impact of the mass value on the additional viscoelastic support reaction and the beam deflection at arbitrary points were determined. The research results of this paper can be helpful for engineers in designing multi-span bridges.

The article deals with modeling and calculations of volumetric machine-building structures with complex geometry. The relevance of the work lies in the fact that its methodology and results can help design massive structural elements complex in shape, including cylinders of powerful hydraulic presses. Attention is paid to the problems of reducing the metal content of machine-building products and the safe conditions of their operation. Theoretical and applied work is based on numerical methods using analytical solutions to assess the reliability of computer calculation results. The choice of research method is because analytical solutions for massive parts of such a configuration are too complex for numerical implementation. Experimental methods are too expensive and not so universal as to sort out possible variants of shapes and sizes. For the actual model of the press, the capabilities of the finite element method implemented in the ANSYS multipurpose complex were selected and rationally used. The results of the calculations are summarized in the table and shown on the graphs of the stress distribution. Based on the performed calculations (with a reliability check based on the formulas of the theory of elasticity for simplified calculation schemes), conclusions were made to ensure a more even distribution of stresses and a reduction in the metal content of the product.

The present study focuses on a new application of TOPSIS to predict and optimize graphene oxide's characteristics. Although this carbon-based material has been investigated previously, its optimization with this method using an automated decision-making process has not been performed yet. The major problem in the design and analysis of this nanomaterial is the lack of information on comparing its characteristics, which has led to the use of diverse methods that have not been appropriately compared. Moreover, their advantages and inconveniences could be investigated better once this investigation provides information on optimizing its candidates. In the current research work, a novel automated decision-making process was used with the TOPSIS algorithm using the Lukasiewicz disjunction, which helped detect the confusion of properties and determine its impact on the rank of candidates. Several characteristics of graphene oxide, such as its antibiofilm activity, hemocompatibility, activity with ferrous ions in hydrogen peroxide, rheological properties, and the cost of its preparation, have been considered in its analysis with TOPSIS. The results of this study revealed that the consideration of the criteria of this nanomaterial as profit or cost criteria would impact the distances of candidates from the alternatives. Moreover, the ranks of the candidates changed when the rheological properties were considered differently in the data analysis. This investigation can help improve the use of this nanomaterial in academic and industrial investigations.

In this study, the general algorithm and technology of design in advanced computer-aided design (CAD) software of the CAD-in-the-Cloud type using an information model (IM) was discussed in detail. Applying design systems of this type increases productivity and quality of the development and enables group work on the project. The proposed information model consists of three main components - working with Autodesk Fusion 360 on a computer, working with cloud capabilities, and designers' collaboration through the cloud. Nevertheless, some IM elements may be missing in a particular design, or there can be options for applying the proposed steps in the design process. Developing customized respiratory protective equipment (face masks) in Autodesk Fusion 360 CAD family was considered as an example of the suggested IM application. Modern design and producing technologies enable the creation of masks according to individual anatomical characteristics of the human face. In this paper, the protective mask was created by applying modern cloud computing technologies using information models. Information models were adapted to the process of protective mask design. The model of a human headform was developed using the 3D scanning method. After applying retopology tools, a basis of the mask frame was created on the surface of a 3D model of a head. Building a solid model and testing the mask fame configuration under mechanical stresses due to facial expression changing was carried out in Autodesk Fusion 360 CAD software. Finally, the cloud module of the generative design was applied to determine the filtering element configuration.

Theoretical studies of physical processes and phenomena in the zone of physical interaction of nanoinstruments with the surfaces of elements of microsystem technology are carried out in work. Based on the conducted research, mathematical models of energy heat exchange in the zone of physical contact of nanometric dimensions were compiled, and their analytical solution was obtained using the Fourier method of separation of variables and Goodman's integral method. Simultaneously, the energy components of the processes in the nanocontact zone were considered. The numerical solution of the mathematical model of energy heat exchange in the zone of physical nanocontact was carried out using a software application based on the finite element method. The results were checked according to the equivalent thermal scheme to confirm the adequacy and accuracy of the obtained models. As a result, the mechanisms of energetic interaction of the nanoinstrument with the surfaces of the elements of microsystem technology devices were clarified. It is shown that the use of the proposed method of equivalent thermal circuits for the evaluation of mathematical models of the energy interaction of nanoinstruments with the surfaces of microsystem technology device elements, as well as the further study of the distribution of thermal fields in the nanocontact zone, differs from other numerical and analytical methods in terms of sufficient accuracy and speed of calculations. At the same time, it was established that the discrepancy between the results of mathematical modeling and the results obtained according to the equivalent thermal scheme does not exceed 5 - 8 %.

Індекс рубрикатора НБУВ: З46-082.05

Рубрики:

Шифр НБУВ: Ж101239 Пошук видання у каталогах НБУВ 

The main reason that restrains the development of seed production of perennial grasses is losses during harvesting, which depend on the agrotechnical properties of plants and the imperfection of existing means. There are no special grass seeds yet. Therefore, serial equipment with special devices is recommended for their collection. There are enough options for technologies for collecting grass seeds. In the article, six main options of technologies used in production were analyzed and compared according to the main indicators. The best results of a comprehensive comparison are those technologies that process the collected seed mass into a stationary one. The design of a device for wiping the seed mass was proposed to develop this direction of grass seed collection technologies. The article presents theoretical and experimental research results that allowed improving these devices based on rational design and operating parameters. Another way to intensify the production process of leguminous grass seeds is to combine the technological processes of wiping and separation in one machine. The analysis of various separating devices showed that machines with a rotating screen of cylindrical or conical shape are best suited for this purpose. The conducted theoretical studies confirmed the hypothesis that extending the time the material stays on the sieve by using a conical surface increases the yield of clean seeds and contributes to uniform loading of the sieve surface, improving the quality of the initial material. According to the research results, the design of the grating-separating block was proposed for the implementation of this scientific hypothesis. The theoretical and experimental studies presented in the article will allow for significantly intensifying the process of collecting grass seeds and outlining the further development of scientific research in this field.

The execution of any project type, especially engineering-based projects, is usually time-based, efficiency-driven, and cost-effective. These factors are the deterministic parameters that engineer successful project completion. The application of scheduling models remains the best technique for achieving these three factors to their best degrees. Therefore, this study was centered on the impact study of applying the scheduling model in harvesting methane gas from methane clathrates deposits. Various data on gas hydrate reserves in the Niger Delta region of Nigeria were collected from relevant literature, studied, and analyzed. Such data includes the pictorial representation and description of the gas hydrate site in the Niger Delta region of Africa and various shapes and sizes of gas hydrate perimeters in the studied region positions of the gas reserves. The normal faults are projected on a bathymetric map of the study area and the bathymetric map of the Pockmark (with the stippled black line indicating the sea floor projection of a prominent N-S trending fracture in 3-D seismic data). As a type of scheduling model, the critical path method (CPM) was applied to develop the project's work sequence using the activity on node (AON) architectural technique and Primavera P6 software after carefully identifying the primary operations involved in the project and their respective sub-operations or work breakdown structure (WBS). The risks associated with each operation were meticulously identified, with their consequent impact and exposure matrix determined using probabilistic measures of 1-5 according to the degree of the risk. Mitigation strategies were recommended for all the identified risks. The cost benefits of the project were X-rayed using parameters such as net present value (NPV), project payback time, internal rate of return (IRR), and net cumulative cash flow. From the results obtained, the CPM schedule showed that the project execution would last approximately ten months. All the operations involved in the project execution plan were all critical, proving that each activity should be completed within the scheduled run period. Else, the entire project would be affected. Also, risks with a high exposure matrix of 25, 12, and 4 were mitigated to 5, 3, and 0 using the recommended strategies. In addition, the project yielded an NPV of $20,736,951.04 for the run period of 22 years after the execution of the project, IRR of 14 %, and a payback time of 8 years (adding 2023 - the year of project execution) provided the daily production rate is maintained within 60,000 - 65,000 MSCF/day. If the daily production rate increases, the cash flow and payback time will decrease. Therefore, the application of CPM in extracting methane gas from gas hydrates positively affected the operation through the vivid insights provided in workflow pattern/methodology risks effects and cost benefits.

Індекс рубрикатора НБУВ: П082.62

Рубрики:

Теплиці

Шифр НБУВ: Ж101239 Пошук видання у каталогах НБУВ 

The article argues that the search for effective tools to ensure the economically secure future of energy companies and their development in the context of green transformation is necessary due to the speed of global transformations, the priority of reducing dependence on fuel and energy imports, the development of renewable energy sources, the instability of the environment for the functioning of energy companies (as a result of russia's full-scale invasion of Ukraine) and their position both on the Ukrainian and European energy markets. The reality of the energy sector in the country and the steps for the recovery of the energy companies determined by the Economic Recovery Plan of Ukraine were analyzed. The evidence shows that the legislative amendments aimed at stabilizing the energy sector and solving key issues lack efficiency and cannot ensure the vital activity of energy enterprises and their development in the conditions of climate-neutral transformation. A methodology was proposed to assess the progress of the carbon-neutral development of energy companies, which should become the basis for attracting ESG investing. The vectors for creating a favorable environment for environmental, social, and governance (ESG) investing were identified as a unique opportunity to ensure the economically secure future of energy companies and their development in the context of green transformation.

This paper applies a novel automated decision-making process with TOPSIS to analyze ions and organic materials in drinking water. The hypothesis was that the modified TOPSIS algorithm with the Lukasiewicz fuzzy disjunction would be appropriate to optimize the drinking water samples. The maximum output values were set to one to apply the fuzzy disjunction. The concentrations of ions and organic materials in the drinking water samples were considered from the values for naturally occurring chemicals that would be of health significance. Materials with positive effects on the body were considered profit criteria, whereas other ones with negative impacts on human health were considered cost criteria. The analysis of samples with unmodified TOPSIS showed that profit criteria having high concentrations and cost criteria having low concentrations had the dominant effects on the candidates' ranking. The modified TOPSIS showed that the candidates' ranking in the second analysis series was the same as in the first. However, the value of 1,0 for the fourth candidate's concentration of nitrite, which resulted from the fuzzy disjunction in the algorithm of the modified TOPSIS, was attributed to the confusion of the drinking water and undrinkable water categories. The optimization results for drinking water samples could be applied in science and engineering based on the concentrations of their ions and organic materials with the automated decision-making process for their distinction from undrinkable water.

Standardization is essential for innovation (on the impacts on design, manufacturing, and operation processes) and its dissemination, both within a country and internationally. A phenomenological information model has been developed for the system of standards, which will be used as an information base for integrated quality management systems, environmental safety, and energy saving depending on the type of products, requirements of technical regulations, and conformity assessment procedures. Phase portraits of the life cycle system of complex products were constructed, and a general expression for the Lyapunov exponents characterizing the overall behavior of the dynamic system in phase space was obtained. The presence of particular areas to which, regardless of the initial conditions, all phase trajectories rapidly evolve has been established. The critical conditions for the control parameters were found. A diagram was constructed that determines the stability of the system states of the life cycle of complex products. It was found that the processes of the life cycle of complex products are carried out in two stages: in the first, there is a rapid evolution of components and parameters of technical and software tools, as well as energetic elements of functional subsystems, which is reflected in a specific attractive section of phase portraits, in the second, further slow development along it.