Mechanical Engineering Problems Research Articles

Main Results of the 27th International Conference on Vacuum Technique and Technology (VTT2020)

In this preface the main results of the 27th International Conference on Vacuum Technique and Technology (VTT2020) that was held on 27–29 October 2020 in Saint Petersburg, Russia are discussed.From 27 to 29 October 2020, the 27th International Conference on Vacuum Technique and Technology was held in the virtual form at the Saint Petersburg Electrotechnical University “LETI”. The Conference was organized by the Ministry of Science and Higher Education of the Russian Federation, Saint Petersburg Electrotechnical University “LETI” named after V I Ulyanov (Lenin), All-Russian Research Institute of Metrology named after D I Mendeleev, Institute of Problems of Mechanical Engineering of the Russian Academy of Sciences, Russian Scientific and Technical Vacuum Society named after Academician S A Vekshinskiy, Peter the Great Saint Petersburg Polytechnic University, Euro-Asian Cooperation of National Metrology Institutes (COOMET), National Metrology Institute (TUBITAK UME, Turkey).List of Images, Organizing Committee, Program Committee, Members, are available in this pdf.

RESEARCH OF THE TECHNOLOGY OF OPENING HOLES IN COMPACT AND POWDER MATERIALS

This article is devoted to one of the important problems of mechanical engineering, including processing by cutting and deploying in sintered antifriction powder material in optimal modes with maximum performance. The study was conducted for small diameter cylindrical bushings. Processing of bushings was carried out by reamers from high-speed and carbide tools on materials from porous powder and cast iron. It is established that the temperature of the tools should not exceed the permissible upper limits, for pressing the bushings, it is necessary to use planting with small strains in the cold state. Keywords: engine valve, bushing, powder material, cast iron, reamer, cold pressing.

Optimization of structural and mechanical engineering problems using the enriched ViS-BLAST method

In this paper, an enhanced Violation-based Sensitivity analysis and Border-Line Adaptive Sliding Technique (ViS-BLAST) will be utilized for optimization of some well-known structural and mechanical engineering problems. ViS-BLAST has already been introduced by the authors for solving truss optimization problems. For those problems, this method showed a satisfactory enactment both in speed and efficiency. The Enriched ViS-BLAST or EVB is introduced to be vastly applicable to any solvable constrained optimization problem without any specific initialization. It uses one-directional step-wise searching technique and mostly limits exploration to the vicinity of FNF border and does not explore the entire design space. It first enters the feasible region very quickly and keeps the feasibility of solutions. For doing this important, EVB groups variables for specifying the desired searching directions in order to moving toward best solutions out or inside feasible domains. EVB was employed for solving seven numerical engineering design problems. Results show that for problems with tiny or even complex feasible regions with a larger number of highly non-linear constraints, EVB has a better performance compared to some records in the literature. This dominance was evaluated in terms of the feasibility of solutions, the quality of optimum objective values found and the total number of function evaluations performed.

On a linear Diophantine equation and its applications

The paper considers a linear Diophantine equation with six variables. Its solution is constructed as a shifted incomplete five-dimensional integer lattice in a six-dimensional space. The basis of this lattice is constructed. An algorithmic solution for finding all its solutions from a given six-dimensional integer parallelepiped is given. For this purpose, a new basis for this incomplete five-dimensional lattice was constructed, which allowed us to write an effective program for finding all sets that satisfy a given Diophantine equation and belong to a given rectangular parallelepiped. As a result of the proposed algorithm implemented in the Mathcad system, it was shown that out of the total number of 10182290760 integer points lying in a given parallelepiped, only 7822045 satisfy the given Diophantine equation. Thus, the total search was reduced by 1301.7 times. The article considers the relationship between shifted lattices and integer programming problems. It is shown how it is possible to construct bases of incomplete integer lattices, which make it possible to reduce a complete search over the points of an s-dimensional rectangular parallelepiped to a search over the points of a shifted incomplete lattice lying in this parallelepiped. Some applications of this Diophantine equation in technical issues related to the solution of an applied mechanical engineering problem in the field of measuring tool design, in particular, sets of end length measures, are considered. The article reflects the iterative nature of the refinement of the mathematical model of this applied problem. After the first model adjustment, the number of sets decreased by another 193.237 times, and after the second model adjustment, the total reduction of sets suitable for subsequent optimization became 581114.6 times. In conclusion, the directions of further research and possible application of the ideas of Hopfield neural networks and machine learning for the implementation of the selection of optimal solutions are indicated.

Integral Thermo-Anemometers for Average Temperature and Airflow Measurement in Ducts, at Anemostat Outlets and in Ventilation Grilles

When creating ventilation systems, it is important to correctly calculate the volumes of air inflow and outflow. If an error is made in the calculation or a redistribution of air flows is required, measurements are indispensable. The existing methods for determining the air flow rate by using point measurements in the cross-section are laborious and time-consuming, and taking readings at different time points introduces a significant error into the result. A. M. Pidhornyi Institute of Mechanical Engineering Problems of the National Academy of Sciences of Ukraine has developed a new hot-wire anemometer whose use greatly simplifies the measuring process. This device allows one to measure the average values of temperature and air velocity (flow rate) in the cross-section of air ducts or at the inlets and outlets of grilles and anemostats, and can be used in real time to monitor and control air flow rate and temperature in ventilation systems. The probe of the hot-wire anemometer is a metal shell with guides on which a sensitive element is laid. Its principle of operation is to change the heat transfer coefficient at different air leakage velocities. The anemometer is preliminarily calibrated in laboratory conditions at various velocities. There has been obtained a calibration dependence that can be used to measure the air flow rate at the inlets and outlets of air distribution devices and directly in the air ducts. To improve the measurement accuracy, it is necessary to provide the 90° angle of airflow leakage on the hot-wire anemometer probe. For this, special air collectors and air flow rectifiers are used.

Analysis of anchor rod failure in a guyed transmission tower: Influence of microstructures and corrosion mechanisms

The mechanical rupture of buried structural components, such as the anchor rods of guyed transmission towers, poses a significant problem in electrical and mechanical engineering. In this work, joint evaluation of anchor rods microstructures, corrosion products, and environmental analysis of corroded anchor rods in a guyed tower was conducted. Microstructural metal analysis, electron microscopy scanning, and backscattered electron diffraction (type FEG-SEM/EBSD) were used to determine the disorientation of the crystalline structure (misorientation angle <5°) and elongated grains with sizes around 2–10 µm. Predominant crystallographic planes (001) and (111) were found to be more susceptible to corrosion than (101). Researchers also observed accumulations of chloride ions in concentrations of up to 10.2% in corrosion products, and in the soil surrounding the anchor rod, chloride and sulfate ions were found in concentrations of up to 5.15% and 2.33%, respectively.

Study of Surface Roughness Effect on a Bluff Body—The Formation of Asymmetric Separation Bubbles

Turbulent flows around bluff bodies are present in a large number of aeronautical, civil, mechanical, naval and oceanic engineering problems and still need comprehension. This paper provides a detailed investigation of turbulent boundary layer flows past a bluff body. The flows are disturbed by superficial roughness effect, one of the most influencing parameters present in engineering applications. A roughness model, recently developed by the authors, is here employed in order to capture the main features of these complex flows. Starting from subcritical Reynolds number simulations (Re = 1.0 × 105), typical phenomena found on critical and supercritical flow regimes are successfully captured, like non-zero lift force and its direction change, drag crisis followed by a gradual increase on this force, and separation and stagnation points displacement. The main contribution of this paper is to present a wide discussion related with the temporal history of aerodynamic loads of a single rough circular cylinder capturing the occurrence of asymmetric separation bubbles generation. The formation of asymmetric separation bubbles is an intrinsic phenomenon of the physical problem, which is successfully reported by our work. Unfortunately, there is a lack of numerical results available in the literature discussing the problem, which has also motivated the present paper. Previous study of our research group has only discussed the drag crisis, without to investigate its gradual increase and the change on lift force direction. Our results again confirm that the Lagrangian vortex method in association with Large-Eddy Simulation (LES) theory enables the development of two-dimensional roughness models.

Analysis of engineering mechanics problems solved by descriptive geometry methods

The article shows the possibility of using descriptive geometry methods for solving problems of theoretical mechanics. The solution of problems of mechanics associated with the analysis of plane and spatial systems of forces is considered. The graphic solution of problems was carried out using the image of force vectors using orthogonal projections. A comparison of the results of graphical constructions with an analytical solution is presented.

A new efficient hybrid approach for reliability-based design optimization problems

The reliability-based design optimization (RBDO) is performed for mechanical design to compromise effectively between economy and safety requirements. In real mechanical applications, such RBDO problems are a highly complex task by involving computational difficulties and its resolution requires the use of appropriate optimization techniques. In this paper, a new RBDO solution approach is introduced for mechanical engineering problems. It is a combination of the reliable design space (RDS) technique with an efficient hybrid algorithm (AMDE-NM) based on the adaptive mixed differential evolution (AMDE) and Nelder–Mead local search (NM). First, the RDS strategy is used to turn the RBDO problem into a simple deterministic optimization (SDO) one, through converting the probabilistic constraints to approximate deterministic constraints, while the resolution is then carried out with the AMDE-NM algorithm. The new proposed integrated approach (RDS–AMDE-NM) is able to handle the mixed design variables with continuous, discrete, and integer types. Six mechanical problems with different features are studied to analyze the applicability and the efficiency of RDS–AMDE-NM. The obtained simulation results show the performance of the proposed approach, while new optimal solutions for two RBDO problems are presented. Furthermore, an industry case on a cylindrical spur gear is studied to investigate the reliability of the proposed method in solving real challenging mechanical RBDO problems. The obtained results reveal really that RDS–AMDE-NM is a promising RBDO approach with extensive applicability.

Fluidized Bed Jet Milling Process Optimized for Mass and Particle Size with a Fuzzy Logic Approach.

The milling process is a complex phenomenon dependent on various technological and material parameters. The development of a fluidized bed jet milling model is of high practical significance, since milling is utilized in many industries, and its complexity is still not sufficiently recognized. Therefore, this research aims to optimize fluidized bed jet milling with the use of fuzzy logic (FL) based approach as one of the primary artificial intelligence (AI) methods. The developed fuzzy logic model (FLMill) of the investigated process allows it to be described as a non-iterative procedure, over a wide range of operating conditions. Working air pressure, rotational speed of the classifier rotor, and time of conducting the test are considered as inputs, while mass and mean Sauter diameter of the product are defined as outputs. Several triangular and constant linguistic terms are used in the developed FLMill model, which was validated against the experimental data. The optimum working air pressure and the test’s conducting time are 500 kPa and 3000 s, respectively. The optimum rotational speed of the classifier is equal to 50 s−1, considering the mass of the grinding product, and 250 s−1 for the mean Sauter diameter of the product. Such operating parameters allow obtaining 243.3 g of grinding product with the mean Sauter diameter of 11 µm. The research proved that the use of fuzzy logic modeling as a computer-based technique of solving mechanical engineering problems allows effective optimization of the fluidized bed jet milling process.

Concepts for E-Assessments in STEM on the Example of Engineering Mechanics

We discuss if and how it is possible to develop meaningful e-assessments in Engineering Mechanics. The focus is on complex example problems, resembling traditional paper-pencil exams. Moreover, the switch to e-assessments should be as transparent as possible for the students, i.e., it shouldn’t lead to additional difficulties, while still maintaining sufficiently high discrimination indices for all questions. Example problems have been designed in such a way, that it is possible to account for a great variety of inputs ranging from graphical to numerical and algebraic as well as string input types. Thanks to the implementation of random variables it is even possible to create an individual set of initial values for every participant. Additionally, when dealing with complex example problems errors carried forward have to be taken into account. Different approaches to do so are detailed and discussed, e.g., pre-defined paths for sub-questions, usage of students’ previous inputs or decision trees. The main finding is that complex example problems in Engineering Mechanics can very well be used in e-assessments if the design of these questions is well structured into meaningful sub-questions and errors carried forward are accounted for.

Sparse representations and compressive sampling approaches in engineering mechanics: A review of theoretical concepts and diverse applications

A review of theoretical concepts and diverse applications of sparse representations and compressive sampling (CS) approaches in engineering mechanics problems is provided from a broad perspective. First, following a presentation of well-established CS concepts and optimization algorithms, attention is directed to currently emerging tools and techniques for enhancing solution sparsity and for exploiting additional information in the data. These include alternative to ℓ1-norm minimization formulations and iterative re-weighting solution schemes, Bayesian approaches, as well as structured sparsity and dictionary learning strategies. Next, CS-based research work of relevance to engineering mechanics problems is categorized and discussed under three distinct application areas: a) inverse problems in structural health monitoring, b) uncertainty modeling and simulation, and c) computationally efficient uncertainty propagation. Notably, the vast majority of problems in all three areas share the challenge of “incomplete data”, addressed by the versatile CS framework. In this regard, incomplete data may manifest themselves in various different forms and can correspond to missing or compressed data, or even refer generally to insufficiently few function evaluations. The primary objective of this review paper relates to identifying and presenting significant contributions in each of the above three application areas in engineering mechanics, with the goal of expediting additional research and development efforts. To this aim, an extensive list of 248 references is provided, composed almost exclusively of books and archival papers, which can be readily available to a potential reader.

Preface

Today we are in a world of information society where we are required to be able to create, access, develop, use, and share information and knowledge individually or in groups. A high potential of the community needs to support the ability and carrying capacity of sustainable development and improve the quality of life. Science is an essential key in the development of industry and information society. Smart work is one way to guarantee an increase in living standards. The industry has changed along with the digitization era, which restructured quickly by embedding and connecting among factories. It has produced an industrial revolution and opportunities for the automation of the new industrialization process. At the same time, competition from the outside world is getting tougher by utilizing knowledge content even though sustainable production can be an advantage in the future.Industry era 4.0 utilizes companies to play the role of digital transformation leaders and to exploit the potential of digitalization. Sustainable production will increase resource efficiency and environmental considerations in competition. This demand will have an impact on solving problems in human life, digital computing, mechanical engineering, electrical, metal, and material engineering, and process engineering, including process complexity, continuous processes in programming, and machine operations. And also it is the basis for supporting interconnection, understanding business and technology, identifying and solving problems, thinking deductively and experimentally, understanding soft skills as well as the importance of technical skills.We hope that these published papers can play a role in the development of the world by empowering the development of science and technology in the competitive industry 4.0.

Preface

This proceeding contains the scholarly papers presented in the 3rd International Conference on Aeronautical, Aerospace and Mechanical Engineering (AAME 2020) held in February, 2020 in Bangkok, Thailand.Submissions to the conference have been reviewed by members of the Technical Committee consisted of professors and senior academics from reputable international universities in Australia, Asia, Europe and South Africa. The papers in this proceeding have passed the vigorous review process and amended to the satisfaction of reviewers. The face-to-face presentations have also undergone critiques by expert audience in the conference. It is on this basis that the published papers in this proceeding are good references to future research investigations and analyses.Papers in the conference can be categorised according to the themes of the conference: aeronautical, aerospace and mechanical engineering. It is worth to note that the purpose of categorisation with these themes is only to help readers to search for papers. The proceeding as a whole presents a consistent focus on aerodynamics, aerostructures, mechanical strength and space exploration technologies. The distribution of papers among these themes is close to balanced, i.e. 9 papers in aeronautical, 6 papers in aerospace and 8 papers in mechanical engineering.Among the 9 papers in aeronautical engineering, structural integrity of aerostructures such as airframe and wing are the most common topics. Another common topic is aerodynamics on aeronautical components which extends into analysis of forces and loading. The novel analyses exhibit in these papers push the boundary of knowledge and enable better aircraft design and manufacture.The 6 papers in aerospace engineering are mostly concerning satellite design, operations and communication. Of particular interest is a paper on aerodynamics performance of hypersonic vehicle and another paper on digital twins. Both papers present innovative concepts in the objective of space exploration. As the technological ability of the world increases, there is evidence that many countries are increasing their research activities in space. The number of papers in this conference is encouraging.The remaining 8 papers are grouped under mechanical engineering theme. Typical mechanical papers such as the lifting mechanism and tie rod of landing gears involve analysis of vibration or shock to mechanisms. It is also nice to see more fundamental mechanical engineering problems such as the research on flatness of large deployable antenna are investigated. Likewise, the research investigating flow-induced vibration of prisms has good potential to develop into more accurate prediction of mechanism interaction with fluid flow.The research rigour and strong theoretical fundamentals demonstrated in the publications in this conference make this proceeding a valuable repository of research topics in aeronautical, aerospace and mechanical engineering. I would like to thank the conference committee, the conference secretariat, keynote speakers and all participants for their hard work making this conference a success.Professor John P.T. MoConference Chair, AAME 2020BSc(Engg), MSc(Engg), PhD(Loughborough), FIEAust CPEng NER APEC Engineer IntPE(Aus), CEng, FIMechE, MHKIE, MFIESchool of EngineeringRMIT UniversityFebruary 2020

Optimization of Interplanetary Trajectories Using the Colliding Bodies Optimization Algorithm

In this paper, a recent physics-based metaheuristic algorithm, the Colliding Bodies Optimization (CBO), already employed to solve problems in civil and mechanical engineering, is proposed for the optimization of interplanetary trajectories by using both indirect and direct approaches. The CBO has an extremely simple formulation and does not depend on any initial conditions. To test the performances of the algorithm, missions with remarkably different orbital transfer energies are considered: from the simple planar case, as the Earth-Mars orbital transfer, to more energetic ones, like a rendezvous with the asteroid Pallas.

PREFACE

The object of the scientific and technical conference "Applied Mechanics and System Dynamics" is the analysis of the current state, trends and prospects for the development of applied mechanics and system dynamics with the aim of improving technology and production and creating new-generation equipment.The conference addresses topical issues of development and research on the problems of mechanical engineering, strength and dynamics of mechanical systems.

Modelling of flexible manufacturing systems

This paper describes an original approach to one of the key problems in modern mechanical engineering – modelling of modern manufacturing systems with regard to the choice of relevant model type. It is shown that in terms of systemology, all the existing models are divided into the imitating (replicating) and optimising ones, while manufacturing system design belongs to semi-structured issues. Therefore, at the macro-designing stage one should use optimising models, rather than the imitating ones. The study provides a broad definition of the technological process as a set of actions aimed at product manufacturing, designing the sequence of relevant steps. It defines production flexibility and adaptation of the manufacturing system to changing conditions. These solutions can be used in automation in manufacturing, computer aided design (CAD) and modelling (CAM), computer aided engineering analysis, flexible manufacturing systems, flexible automation and production engineering.

Modelling of flexible manufacturing systems

This paper describes an original approach to one of the key problems in modern mechanical engineering – modelling of modern manufacturing systems with regard to the choice of relevant model type. It is shown that in terms of systemology, all the existing models are divided into the imitating (replicating) and optimising ones, while manufacturing system design belongs to semi-structured issues. Therefore, at the macro-designing stage one should use optimising models, rather than the imitating ones. The study provides a broad definition of the technological process as a set of actions aimed at product manufacturing, designing the sequence of relevant steps. It defines production flexibility and adaptation of the manufacturing system to changing conditions. These solutions can be used in automation in manufacturing, computer aided design (CAD) and modelling (CAM), computer aided engineering analysis, flexible manufacturing systems, flexible automation and production engineering.

Preface

We are pleased to introduce the Proceedings of the 31th International Conference of Young Scientists and Students “Topical Problems of Mechanical Engineering 2019” (TopME 2019).The Conference was held from December 4th to December 6th, 2019 in Moscow, Russia. It was organized by the Blagonravov Mechanical Engineering Research Institute of the Russian Academy of Sciences (IMASH RAS).The scientific sections of the Conference covered a wide range of topics on materials science, strength, survivability and safety of machines, tribology, vibration processes and systems, machines mechanics and biomechanics.

Внедрение систем автоматизированного проектирования (САПР) на машиностроительном предприятии: ограничения и возможности

The article highlights issues related to factors that affect the introduction of computer-aided design (CAD) systems in modern machine-building industries. The purpose of the work is to determine the main limitations and possibilities of using CAD in production and to consider the main trends in the development of system solutions for mechanical engineering problems. The theoretical basis of the work is data analysis and analytical study of the current state of proposals for CAD solutions. Electronic modeling systems allow not only to optimize the production process, reduce costs, but also are indispensable requirements for the competitiveness of modern engineering products on the world market. They allow you to carry out operational, remote interaction on the development and production of products, bringing it to the international market. Despite the variety of possibilities offered by CAD solutions from various companies and vendors, the request for its implementation by enterprises is very limited. The crisis state of the economy and industrial production is also not an incentive to implement such solutions. In this regard, it is necessary, on the one hand, to study in detail the evaluation of the effectiveness of implementing CAD technologies, and on the other hand - the most flexible software products that are adapted to the real capabilities and requirements of a particular enterprise, production process, and final product.