bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue behaviour of 10% wt. short glass fibre reinforced recycled Polypropylene with mineral filler in presence of notches
Authors: Coppola F , Ricotta M , Garilli M , Fabbro L , Azzalin I , Meneghetti G 
Published: February 2024

Abstract
An experimental investigation of the fatigue behaviour of plain and notched specimens made of 10% wt. short glass fibre reinforced partially recycled Polypropylene filled with mineral filler is presented. To this end, plain and V-notched specimens (with notch radius ranging from 0.07 mm to 10 mm) were produced by injection moulding and tested under tension-tension fatigue. During the fatigue test, the damage evolution was monitored using a traveling microscope to define the number of cycles spent for the fatigue crack initiation. The fracture surfaces were analysed at microscopic level in order to investigate the fatigue damage mechanisms of plain and notched specimens. The fatigue tests were first analysed in terms of net stress amplitude to define the stress-life curves. Then, an energy-based approach was proposed to reduce the scatter of the fatigue data of plain and notched specimens. Starting from the damage evolution observed during the fatigue tests, the model relies on the strain energy density numerically evaluated in the matrix and averaged on a structural volume embracing the notch tip.
Random vibration-based progressive fatigue damage monitoring in thermoplastic coupons: a preliminary investigation
Authors: Tsivouraki N , Tserpes K , Fassois S 
Published: February 2024

Abstract
In recent years there has been an increasing trend towards the utilization of composites, particularly thermoplastics, in various components of aerostructures. The prelusion of such materials has underscored the significance of investigating their fatigue behavior and developing reliable methods for detecting fatigue damage. In this context, vibration-based techniques hold significant potential as they leverage the inherent excitation provided by in-flight noise and turbulence. This study aims at assessing the progressively accumulated fatigue damage in thermoplastic coupons via random vibration signals while accounting for operational and inter-structural uncertainties. The experimental process consists of preliminary tension and fatigue tests, interrupted fatigue tests, C-Scan inspection tests, and non-contact random vibration tests. Consecutive fatigue states are obtained by performing fatigue tests at intervals of 10 000 cycles for a population of 7 coupons. At each interruption, ultrasonic C-Scan and vibration inspection tests are performed, allowing for the visualization of fatigue damage and random vibration signal analysis. Welch Power Spectral Density estimates are employed and are shown to have good potential for distinguishing among different fatigue states despite the inevitable population and experimental uncertainty. Furthermore, fatigue damage is found to progress symmetrically and laterally along the free edges of the test coupons, which is explained by the free edge effect.
Fatigue strength assessment of preloaded cross-toothed flange connections based on the FKM guidelines
Authors: Härtel H. , Ulrich C. , Fiedler M. , Kästner M. , Schlecht B. 
Published: February 2024

Abstract
Cross-toothed flange connections are used in drivetrains for form-fit coupling of shafts. They belong to the group of non-shiftable couplings. Compared to frictional connections, tooth flange connections can transmit significantly higher torques in the same space. In contrast to other tooth couplings, the crossed tooth flange coupling investigated here is characterized by a particularly complex load distribution. The preload force, which is necessary to transmit operational loads, is generated by tensioning bolts, which can be located centrally or decentralized. Thus, the stress condition in the notch of the coupling is always determined by a superposition of stresses from preload force and operating loads.
Extensive experimental and simulative investigations were carried out as a part of a research project. In addition to the development of a pragmatic, specially adapted calculation concept for cross-toothed couplings for practice, the experimental tests were accompanied by calculations with the FKM guideline “Analytical Strength Assessment” and the FKM guideline “non-linear”, The determination of local stresses was carried out with the help of elasticity theoretical and elastic-plastic FE full-contact calculations based on experimentally determined material data.
This article deals with the possibilities of calculations based on the FE simulation results using the above mentioned FKM guidelines. The experimentally determined load-carrying capacity is critically compared to the calculation results. The focus is on the implementation of the fatigue strength analysis in the context of the corresponding boundary conditions. Topics such as the assumed knee point of the Wöhler curve to the fatigue strength range are discussed as well as the evaluation options for elastic-plastic FE results for the guideline „non-linear”.
Notch approximation methods for components under thermomechanical stresses
Authors: Hamacher Jan , Kraft Jan , Vormwald Michael 
Published: February 2024

Abstract
In this paper two different kinds of notch approximation methods are presented. The proposed methods are known as the incremental notch approximation method (e. g. Neuber method [1] or ESED [2, 3]) and the structural yield surface approach (SFF) (after Köttgen et al. [3]), while two different approaches of the SFF are used. All methods are capable to handle multiaxial cyclic loading. For a validation, the methods are compared to the results of a finite element analysis (FEA) of a notched component. The presented comparison is made for a non-proportional loading case. One objective of the work is to find out, which is suitable to extend it to thermomechanical loads as a next step.
Wear and Friction Behaviour of Additive Manufactured PEEK under Non-conformal Contact
Authors: Chen Y K , Lin G B , Shukur Z M , Kukureka S N , Dearn K D 
Published: February 2024

Abstract
Tribological properties of laser sintered polyether-ether-ketone (EOS PEEK HP3) were investigated using a rolling-sliding test rig. This investigation aimed to study the wear and friction failure mechanism of EOS PEEK HP3. The main objectives included to conduct wear and friction tests under non-conformal contact, to monitor surface temperature, to carry out surface characterization with microscopy. With this rolling-sliding test rig, tests were carried out on an EOS PEEK HP3 specimen running against a steel disc unlubricated, with various slip-ratios under a contact pressure of 56 MPa, 48 MPa and 39 MPa respectively. Both wear and friction were measured. The results have shown that both friction and wear were increased with an increase of either slip-ratios or the contact pressures, exacerbated by high surface temperatures. It has also been observed that both friction and wear failures were associated with the degradation of the non-conformal contact surfaces due to crystallinity changes that correlated well with working conditions. Using microscopy it was found that such failures as pitting, fatigue and surface cracking were affected by the surfaces in contact, including the degree of melting of the surface. Based on the observation on the contact surfaces, the failure mechanisms of EOS PEEK HP3 include surface melting and contact fatigue failures with the high slip-ratio and the high contact pressure conditions. The findings of this investigation have the potential to help to design & develop additive manufacturing PEEK products. Typically, these results can be used in a design process for a more effective polymeric gear system.
Bird strike analysis of new composite inlet for tilt rotor aircraft
Authors: Doubrava R , Vlach J , Oberthor M , Bělský P 
Published: February 2024

Abstract
Bird strikes are an important phenomenon to consider when designing and servicing aircraft structures. Most major bird strike incidents result in aircraft propulsion damage. Because an engine is the sole thrust-providing system of an aircraft, the effect of bird strikes on engine inlets and systems must be investigated and mitigated to the maximum extent. Especially in the case of (vertical take-off and landing) VTOL aircraft, such as an aircraft with tilting rotors, this effect is critical from the point of view of the operation, from the point of view of flight mechanics and the overall control of the aircraft. This work aims to propose the proof of resistance of a new composite air inlet for a new tilting rotor aircraft, which is experimentally verified and supported by numerical simulations performed on flat and simple curved test panels. The new, very effective method was used to calibrate the composite material model, which is further used in the following numerical simulations.
Overview of the V International Conference on Applied Physics, Information Technologies and Engineering - APITECH-V 2023
Authors: Siddikova Sadokat , Yuldashev Narbek , Juraeva Malokhat , Abrorov Akbar , Kuvoncheva Matluba 
Published: February 2024

Abstract
The overview describes the main directions and results of the V International Conference APITECH-V 2023 held in Bukhara, Uzbekistan on 26-28 October 2023. It gives the details about the participants and the proceedings. The purpose of the Conference is to share the experience of leading experts in the application of modern methods of applied physics and information technology in high-tech production, in the fields of aerospace, energy, chemical and oil and gas engineering.
List of International Programme Committee is available in the Pdf.
Fatigue analysis of concrete structures using AI with the introduction of fractal corrosion detection
Authors: Donenko V , Donenko I , Bobrakov A , Kulik M , Ivanenko D 
Published: February 2024

Abstract
The article is devoted to the study of fatigue of concrete structures using modern artificial intelligence technologies. The main attention is paid to the use of machine vision for the fractal analysis of reinforced concrete structures. The article presents models optimized for operation in machine vision conditions, which makes it possible to detect signs of corrosion and fatigue with high accuracy and speed. A feature of the presented method is the use of a unique method of infinite fractal discrimination, which allows you to analyze the concrete structure in detail at the micro level. This method reveals unique features and heterogeneities in the structure of the material, which contributes to a more accurate prediction of its behavior under various influences. The application of this approach can become revolutionary in the field of diagnostics and maintenance of infrastructure facilities.
Analysis of the current density and electrolyte composition influence on the quality of micro-arc coatings
Authors: Pecherskaya E A , Li Qiang , Zhurina A E , Golubkov P E , Shepeleva J V 
Published: February 2024

Abstract
The results of an experimental study of oxide coatings obtained using an automated system developed by the authors in the anode-cathode mode at a ratio of the anode current to the cathode current equal to 1, at low current (0.125 A or 0.25 A) with different electrolyte composition are presented. An analysis of the dependence of the quality of the obtained coatings on the molding curves, which characterize the change in the electrical voltage on the samples depending on the time of their processing was made. It has been established that with increasing current density, the process is more intense, microdischarges begin to burn earlier, and, in general, the coating quality increases. However, at too high current densities (50 A/dm2), it is undesirable to carry out micro-arc oxidation treatment due to an increase in the coating roughness. In particular, it is expedient to use the results obtained for quality control of the technological mode under production conditions: the coating has inadequate quality if the molding curve has a distorted shape. The results obtained have been tested in the implementation of the method of formation by microarc oxidation of oxide coatings with specified properties.
To the theory of dimensional quantization in crystals in the Kane approximation
Authors: Ya Rasulov R , Rasulov V R , Eshboltayev I M , Kuchkarov M , Urinova K K 
Published: February 2024

Abstract
The microscopic mechanism of size quantization of the conduction band and valence band of semiconductors of cubic and tetrahedral symmetry has been theoretically studied in the Kane approximation. It is shown that the matrix Schrödinger equation obtained on the basis of the Kane model cannot be solved analytically for a potential well of an arbitrary profile. Therefore, expressions for the energy spectrum are obtained depending on the two-dimensional wave vector directed along the interface of the heterostructure for various cases that differ in the range of current carrier energy values.
Dimensional quantization in InSb and GaAs in three-zone model
Authors: Ya Rasulov R , Rasulov V R , Akhmedov B B , Muminov I A , Urinova K K 
Published: February 2024

Abstract
Various cases of size quantization in narrow-gap crystals of cubic or tetrahedral symmetry in the three-band Kane approximation are analyzed. Expressions for the energy spectrum depending on the two-dimensional wave vector are obtained for two different cases, differing in the range of current carrier energy values. The size-quantized energy spectrum of electrons in the conduction band and holes in the subband of light holes in InSb and GaAs semiconductors is analyzed in the three-band Kane model.
Fuzzy system of automatic tuning of electromagnetic excitation system of vibration-frequency liquid density meter
Authors: Huseynov T K , Abdulova N A , Huseymov T T , Hashimova A R , Shirinova A Y 
Published: February 2024

Abstract
A fuzzy system for setting the location of electromagnetic exciter of vibration-frequency density meter is presented, taking into account the possible nonlinearities of the object. This paper proposes a system and algorithm for tuning the location of electromagnetic exciter of vibration-frequency density meter using fuzzy set theory. The use of fuzzy control methods allowed us to obtain a system for tuning the location of the electromagnetic exciter of the vibration-frequency density meter without the use of cumbersome computational procedures characteristic of the classical control method.
Photocatalytic activity of ZnO-Zn nanoparticles after nanosilver covering and annealing
Authors: Gerasimov A S , Balezin M E , Ilves V G , Sokovnin S Yu 
Published: February 2024

Abstract
The research evaluated the photocatalytic activity (PCA) of zinc oxide nanoparticles (NPs) produced by pulsed electron beam evaporation (PEBE). The ability of NPs to accelerate the photodegradation of methyl violet dye under UV exposure was considered. The paper presents an analysis of changes in catalytic activity after annealing and coating with nanosilver of the studied samples. It has been shown that as the annealing temperature increases, the PCA increases, especially for doped particles. The highest catalytic ability was shown by doped NPs ZnO-Zn+Ag annealed at a temperature of 400 °C. This sample allowed to increase the photodegradation of the organic dye by more than 6.5 times compared to the control.
Investigation of the inlet useful temperature difference effect on the distribution of hydrodynamic characteristics of the vapor-liquid flow inside the falling-film evaporator heating tube designed for a nitric acid solutions evaporation
Authors: Khomyakov A P , Gushshamova V N , Mordanov S V , Khomyakova T V , Vlasova E A 
Published: February 2024

Abstract
We present the results of mathematical modeling of effect of inlet useful temperature difference on the vapor- liquid flow in the heat exchange tube of a vertical evaporating film apparatus, which is designed for evaporation of nitric acid solutions. Distributions obtained along the heat exchange tube length of local values of the: mass flow rate of the fluid and secondary steam, the velocity of the fluid film, the velocity of the secondary steam, the Reynolds criterion of the liquid and vapor phases, the absolute pressure depending on the values of this useful temperature difference. The study was carried out using numerical simulation. To study the effect of the initial useful temperature difference on the hydrodynamics of the vapor-liquid flow, the vertical evaporator equipped with the tube ø38x3 mm and length of L = 4 m was adopted. The linear nature of the distribution of hydrodynamic parameters along the length of the heat exchange tube is established. The absolute pressure in the tube space decreases along the heating tube due to pressure drop. The limiting factor in reducing the absolute pressure is the friction losses of the secondary vapor on the solution film surface. A decrease in the pressure in the tube space leads to decrease in the boiling point of the solution. This leads to increase useful temperature. This has a positive effect on the evaporation efficiency The obtained data should be used in the design of evaporation plants, which are designed for evaporation of nitric acid solutions.
Physical and mechanical modeling of shaping pneumatic formwork by bicubic splines
Authors: Yadgarov Uktam , Akhmedov Yunus , Asadov Shukhrat , Badiev Makhmud 
Published: February 2024

Abstract
The article deals with the hierarchical design structure, consisting of four stages of the stress state of pneumatic shells. The main tasks of designing and constructing pneumatic formworks during the construction of thin-walled architectural shells are considered. The introduction of pneumatic formwork into architectural and construction practice has a significant impact on the ability of the architect, builder and designer in the search for new and more advanced forms, as well as the builder in translating the creative ideas of the architect into steel and modern concrete. Thanks to the flexibility and elasticity of the material, it allows the construction of curvilinear spatial shells of a new elastic quality level. The proposed geometric model makes it possible to obtain a variety of software as well as the formation of a discrete-point frame of a finite shape by bicubic splines, which provides a predetermined accuracy for solving subsequent software design and construction problems.
Study of dynamics of the turning process in pneumechanical spinning in the presence of false torsion
Authors: Sayidmuradov Mirzokhid , Khudayberdiyev Abdukarim , Abdullajonov Nosirjon 
Published: February 2024

Abstract
The paper presents the results of a study of the dynamics of the process of torsion of yarn of pneumomechanical spinning in the presence of false torsion. Dynamic mathematical models of the process of torsion of yarn of pneumomechanical spinning in the presence of false torsion in unsteady modes of starting and stopping the forming-twisting device are constructed. By now, the question of yarn twisting in a transient mode of operation in rotor spinning remains unexplored. We have here made an attempt to fill the indicated gap by constructing mathematical models of a forming-twisting device during torsion. In connection with the above-mentioned problem arises to systematize the accumulated information on new methods of forming yarn and constructions of forming and torque devices, to clarify a number of questions of theory and technology, and also to classify methods of forming yarn. The main direction of development of new methods of yarn formation remains the improvement of the high-speed modes of the working organs and, above all, of the forming and turning devices, which raises a number of important problems of both technological and structural nature.
Computational approach based on use of multilayer neural networks in classification of rail line states
Authors: Tarasova Anna E , Tarasov Evgeny M , Zolkin Alexander L , Pestin Vyacheslav A , Bityutskiy Alexey S 
Published: February 2024

Abstract
The article considers the issue of classification of the states of rail lines using multilayer neural networks. It is shown that with significant external disturbing influences, the most promising direction is the retraining of classification models using neural networks. The representativeness of the sample is proposed to be realized by applying the scaling of informative features. It is proposed to minimize classification errors by gradient optimization methods. In the work during classification of rail lines states by neural networks, at the first stage, artificial classes of states are formed. At the second stage, the classification of states by the trained neural network is considered, classification errors are identified. On the basis of these errors the network is retrained until acceptable results are obtained. The article presents neuron learning algorithms: Hebb’s algorithm, error backpropagation method (for training a multilayer neural network), Konohen’s, Hopfield’s, Hamming’s algorithm and network. In the presented revision of the classification model, the correction is carried out according to the Widrow-Hoff algorithm.
Solutions to the problem of differential games with electric oscillations by finite difference methods
Authors: Mamatov Mashrabjon 
Published: February 2024

Abstract
The article deals with the issues of electromagnetic processes from the point of view of application technology. The problem of voltage normalization in lines in the presence of opposing external forces is studied. The process of realizing the solution of this problem is based on the introduction of a mathematical model of electromagnetic processes occurring in lines as a continuous differential pursuit game described by hyperbolic equations. The finite difference method transforms the continuous pursuit problem into a discrete game. Sufficient conditions are obtained getting into neighbourhood. And with the help of a well-known a priori estimate for the difference between the solutions of a continuous differential and the corresponding discrete game, sufficient conditions are obtained for the possibility of completing the pursuit of a continuous game. A pursuer outputs terminal set, which is voltage normalization.
Using numerical simulation to analyze the strength properties of the developed demountable body of a trolley
Authors: Peshkov R A , Tretyakov P A , Fedorov A V , Kuplevatsky D V , Mineev A V 
Published: February 2024

Abstract
One of the safest types of public transport is the metro, which is actively developing in many countries. Despite a number of advantages, the construction of metro tunnels is a rather labor-intensive process, which involves complex technical equipment in the form of tunnel boring complexes. Tunnel boring complexes include locomotives that perform the functions of hauling away rock using trolley with removable body. Trolley differs from their usual characteristics - in weight, dimensions, as well as the component composition of individual systems, in particular the compressed-air braking system. The article is devoted to the analysis of the parameters of the stress-strain state of one of the main load-bearing elements of a trolley- the casing. As a result of the analysis, design loading cases were selected, the most loaded parts of the body were determined, recommendations were formed for choosing the optimal material thickness of various elements and increasing the load-bearing capacity of the body.