Mechanics and Advanced Technologies

Correction of the Control Program for End Milling on a CNC Machine

2025-08-25T12:19:08+03:00

The results of experimental testing of the correction of the CNC-programs for end milling on a CNC machine are presented. The correction is performed for serial and single-piece production conditions using the method of control using a posteriori information. A posteriori information is determined during measurements directly on the CNC machine with a three-coordinate probe from Renishaw. Moreover, for serial production, the pre-machined part is measured, and for single-piece production, the machining allowance is divided into two parts and the surface machined in the first pass is measured. The correction is performed using the experimentally determined transfer function of the machining system. The effectiveness of the developed methods has been experimentally proven: after milling the first part, the average error was 0.1 mm, and after machining the second part (and subsequent ones) using the corrected control program, the error decreased to 0.012 mm, i.e. the machining accuracy is increased by more than 8 times. In the conditions of single production, when dividing the allowance into two parts and determining the correction according to the calculated transfer function, the machining error decreased by more than 6 times. The time loss for performing two passes in the conditions of single production does not exceed the machining time according to traditional technology, when to ensure the specified accuracy it is necessary to perform several passes according to the same control program.

Comparison and Evaluation of Conventional and Machine Learning-Assisted Reverse Engineering Workflows

2025-06-23T11:19:57+03:00

Reverse engineering workflows play a crucial role in converting physical components into digital CAD models, impacting efficiency and accuracy in various industries. Traditional manual approaches, while highly precise, are often slow and resource-intensive, prompting exploration of machine learning (ML) methods promising accelerated results. The aim of this study is to perform a comparative overview and practical evaluation of conventional and ML-assisted reverse engineering workflows, identifying their accuracy, speed, and applicability to support evidence-based recommendations for workflow selection. As part of the study, a steel chuck-jaw was scanned using a high-precision scanner as an example of a part for reverse engineering. Three distinct CAD models were created: the first by manual surfacing in CATIA V5, the second by semi-automatic fitting in Geomagic Design X, and the third using the ML-based Point2CAD pipeline followed by post-processing in Geomagic Design X. The models were then assessed by comparing surface-to-cloud deviations and the total time required for reconstruction. The manual CATIA workflow achieved the best accuracy but demanded significant time and hands-on effort. The semi-automatic Geomagic workflow offered an effective balance between accuracy and efficiency. The Point2CAD approach dramatically reduced reconstruction time but resulted in significant local deviations, even though the overall geometry was acceptably maintained. These results suggest selecting manual workflow for tasks where accuracy is critical, semi-automatic workflow can be recommended for standard precision tasks with balanced effort, and ML-assisted workflow – for rapid prototyping or digital archiving when moderate inaccuracy is permissible and the necessary hardware is available. Additionally, the comparative overview underscores that selecting a suitable reverse engineering workflow depends significantly on project-specific requirements, particularly regarding required accuracy, available hardware, and acceptable processing time.

Automation of Laser Beam Technological Applications

2025-05-26T18:14:33+03:00

The object of the analysis is condition and the level of usage of laser beam as a tool (both quantitative and qualitative) in different technological environments (medicine, material processing, measurements at al.).
Practical experience in the development and implementation of technological application of laser beam and extensive research of world best practices confirmed that the main factors of its applications are the efficiency of interaction with various materials, wide range of controllable beam power (up to 2.3 MW) and high levels of beam intensity in laser beam processing zone (up to 10²⁰ W/cm²) due to its small cross-section (up to 10^–9 m) and short interaction time (10^–15 s). On the other hand, some properties of laser beam were not taken into account as they are rarely used in technological applications.
The goal of this publication data is to increase the quality of technological applications of laser beam as a tool by utilization of the full spectrum of its unique properties.
Among them are the non-materiality of laser beam as a tool, transparency, and ease of control of its key parameters (wavelength, energetic and spatial characteristics). Successful management of these characteristics significantly increases organizational properties of numerous technological applications of laser beam as a tool.
Transparency and non-materiality of electromagnetic energy of laser beam allow to combine the interaction of laser beam with material and simultaneous evaluation (measurement) of laser beam processing results. Such an active control gives data to manage the progress and outcome of processing by controlling laser beam processing parameters, introducing self-adaptivity of technological operations. Unfortunately, there is no information on adaptive development of technological processes that use laser beam as a tool.

Digital Twins as a Tool for Improving the Efficiency of the Milling Process

2025-08-27T16:35:52+03:00

In modern mechanical engineering, milling remains the most widespread and highly productive shaping process. However, the complex dynamics of the cutting forces between the tool and the workpiece, along with other phenomena accompanying machining, limit productivity improvements without compromising surface quality. One of the effective approaches to enhancing milling productivity while maintaining accuracy is the application of digital twins for monitoring and controlling the milling process.
The aim of this study is to review and summarize current approaches and developments related to the creation and use of digital twins to improve the efficiency of the milling process.
The methodology is based on a systematic review of publications from 2018–2025 in leading scientific databases (Scopus, ScienceDirect, SpringerLink, Google Scholar), selected according to the following criteria: concept development, availability of structural (architectural) descriptions, experimental results, and practical implementation of digital twins in milling.
More than 30 publications were analyzed, of which 12 articles meeting the above criteria and focusing exclusively on digital twins of the milling process were examined in detail.
The results of the study showed that the most successful digital twin architectures for milling are based on multi-layer structures integrating sensor data, mathematical models, and artificial intelligence algorithms. The implementation of bidirectional feedback enables real-time prediction of tool wear, compensation of thin-walled workpiece deformations, and stabilization of surface quality parameters. Several studies reported reduced dimensional errors, fewer defective parts, and increased tool life.
Digital twins in milling demonstrate significant practical value by combining simulation, monitoring, and process control. Further development requires the unification of architectures, the creation of open integration platforms, and the adoption of hybrid computing solutions, which will ensure scalability and industrial implementation of this technology.

Horizontal Biomass Gasifier in Zakho: Computational Guide and Investigation

2025-05-22T03:03:35+03:00

The horizontal biomass gasifier represents a promising and sustainable solution for addressing both the growing energy needs and environmental challenges in Zakho City, Iraq. This study explores the utilization of locally available biomass waste to produce clean, renewable energy through a horizontal burner gasifier system. By converting organic waste into combustible gas, the system offers a practical pathway toward reducing pollution and mitigating the environmental impact of waste accumulation. The primary goal of this research is the development, validation, and optimization of a computational model capable of accurately predicting the thermal and fluid dynamics of a horizontally configured gasifier under local operating conditions. Using Computational Fluid Dynamics (CFD) simulations in ANSYS Fluent 2024 R2, the study investigates combustion dynamics, temperature distribution, flow behavior, and heat transfer within the gasifier. The model was constructed based on actual geometry, fuel properties, and pressure-driven boundary conditions, ensuring realistic physical representation. A mesh-independence study confirmed numerical stability, while turbulent flow and combustion were modeled using the standard k–ε and eddy-dissipation approaches. Validation against published experimental data demonstrated excellent agreement, with less than 6 % deviation from reported results. Parametric optimization revealed that an air flow rate of 28–32 m³/h yields a maximum temperature of approximately 1450 °C and a thermal efficiency near 91 %, establishing the optimum operational range for this configuration. The horizontal orientation exhibited more uniform temperature gradients and improved mixing compared to vertical systems. This revised investigation not only strengthens the physical and computational understanding of biomass gasification in horizontal systems but also provides a robust modeling foundation for future 3D simulations and experimental validation, supporting broader adoption of biomass-based renewable energy technologies in similar regions.

Study of the stability of the formation of the primary layer of steel powder in the technology of Powder Bed Fusion by Tungsten Inert Gas welding

2025-08-11T13:56:40+03:00

A comprehensive study of the possibility of using TIG (Tungsten Inert Gas) arc welding as Powder Bed Fusion (PBF) for additive manufacturing of metal products was conducted. The method of forming the primary surfacing layer by local melting of the pre-applied layer of metal powder without adding filler material is proposed and experimentally verified. Steel powder with an average particle size of about 300 μm, applied dry on a St3 grade steel substrate, was used as the starting material. The optimal parameters of the welding process were determined: current strength 120 A, arc voltage 30.5 V and torch movement speed 455 mm/min. The stability of the arc process, the formation of a homogeneous continuous deposited layer without obvious surface defects was confirmed experimentally. The obtained results indicate the significant potential of the proposed TIG-PBF technology as an economic alternative to traditional laser and electron beam methods in additive manufacturing, which can become the basis for the development of hybrid manufacturing technologies that combine 3D printing and mechanical processing.

Numerical modeling and Digital Twins in Wire Arc Additive Manufacturing

2025-09-09T06:49:29+03:00

Wire Arc Additive Manufacturing (WAAM) has become a valuable tool for cost-effective production of large metal structures with complex geometry using established arc-welding hardware and wire feedstock. However, the complexity of underlying physics makes it difficult to predict the geometry and stress state of final products. Heat accumulation, inter-pass temperature, and path planning influence bead shape and defect formation, while cyclic thermal loading induces residual stresses and distortion, which hinder repeatability and certification. High-fidelity numerical modelling, while being important for studying and optimization of WAAM process, remains unsuitable for real time simulation and control due to high computational cost. In order to overcome the limitations of pure physics-based models, the interest has shifted to hybrid workflows— combined physics-based and data-driven models calibrated by real-time sensing—embedded in Digital Twin architectures to support prediction, monitoring, and process control. The objective of this study is to systemise recent advances in multi-scale multi-physics numerical modelling for wire arc additive manufacturing (WAAM) and provide insight into Digital Twin (DT) architectures alongside data-driven approaches based on artificial intelligence (AI), machine learning (ML) and data management. The extensive literature review was performed to reveal advantages and limitations of these simulation method and how they could transition WAAM to intelligent manufacturing, driven by multiple data streams, with real-time monitoring, predictive analytics, and autonomous correction. The results of the review can be used in future studies to organize and assemble intelligent WAAM systems in laboratory experimental conditions with a perspective of industrial applications.

A Review of Abrasive Water Jet Cutting Technology for Composite Materials

2024-11-22T14:12:28+02:00

With the growing demand for high-precision and high-reliability machining of composite materials in aerospace, automotive, and electronics industries, abrasive waterjet (AWJ) technology has emerged as a promising method for cutting non-metallic composites due to its cold cutting nature and multi-material adaptability. Compared with pre-2020 studies that mainly focused on parameter trials, recent research has shifted towards modeling of cutting-induced damage, microstructure-level precision control, intelligent optimization, and real-time monitoring, indicating a dual advancement in mechanism understanding and system-level integration. This review summarizes typical damage modes and modeling methods in AWJ cutting of composite materials, compares the applicability of various predictive models and quality indicators, and evaluates representative optimization strategies across different composite systems. Furthermore, it highlights trends in AWJ system intelligence, including acoustic emission monitoring, AI-based modeling, and the integration of digital twin technologies. Future challenges are identified, such as multi-scale modeling of damage–performance coupling, closed-loop process control, and standardized quality assessment frameworks. This review aims to provide structured insights and forward-looking references for advancing AWJ in composite precision manufacturing.

Response of the Structure and Characteristics of the Outlet Flow of a Vortex Mixing Chamber to Changes in Design Parameters. Part 1

2025-08-11T14:24:40+03:00

The results of an experimental study of the little-studied phenomenon of the influence of vortex formations of the dead end part of a vortex mixing chamber of the end type on the structure and integral characteristics of the output flow are presented. Thermoanemometric studies on a model sample of a vortex chamber of a typical design made it possible to identify the reaction of the profiles of the components of the time-averaged local velocity and the relative intensity of the flow velocity pulsations, which determine the efficiency of mixing and heat and mass transfer, to the complex variation of the axial angles a of the tangential supply of the medium to the chamber cavity and the relative depth of its dead end part L^* = L/d₀ (d₀ is the diameter of the chamber). Zones of localization of almost isotropic turbulence with uniform mixing of the working medium in coherent vortex formations were identified. It was found that at a = +20° the increase in the value of L^* from 0 to 4.4 is accompanied by a more regular in terms of Re number character, compared to the chamber variant with a = –20°, of the redistribution of the kinetic energy of the swirling flow from the rotational to the axial components of the motion with a simultaneous increase of 15–17 % in the intensity of transverse pulsations in the studied range of Reynolds numbers
Re = 47080÷86530. Under these conditions two-dimensional pulsation intensity averaged over the output cross section for the chamber with a = +20° increases from 13 % to 17 % against (3–9) % increase for the variant a = –20°. Therefore, the combination of chamber parameters a = +20° and L^* = 4.4 can be considered as one of the simplest constructive and effective control actions on the transfer processes in swirling flows of working media, which is important in the design of combustion chambers, rocket engines, power plants, chemical reactors, etc.

Mathematical Modeling of the Interaction Between Propulsion Systems of High-Mobility Ground Robotic Systems and Soil

2025-08-08T16:09:00+03:00

This study focuses on improving the off-road performance of ground and hybrid mobile robotic systems (MRS) operating under challenging terrain and surface conditions, particularly on soft soils and uneven surfaces. The focus is on the development of mathematical models and computer simulation of the interaction between different types of propulsion systems wheeled and tracked - and the terrain. A methodology for evaluating contact interaction, taking into account the nonlinear properties of materials and complex geometrical shapes, is proposed. In particular, a series of numerical experiments was conducted in ANSYS (Transient Structural module), simulating the deformation interaction of wheeled and tracked propulsion systems with the soil. To enhance the reliability of the results, an orthotropic soil model was used, reflecting its layered structure and anisotropy of mechanical properties, along with exponentially nonlinear characteristics of rubber determined from experimental stress–strain curves. This approach allowed for a mathematical description of the complex process of contact patch formation, evaluation of stress and pressure distribution within the contact zone, and determination of the patterns of contact area and settlement changes under applied external loads. The practical significance of this work lies in the possibility of using the developed models during the design phase of robotic systems, particularly for predicting traction performance, estimating energy consumption, and optimizing mobility parameters under various terrain conditions.

Analysis of Energy-Saving Methods in Hydraulic Drives of Mobile Machines

2025-06-20T15:43:13+03:00

Search for Effective Energy-Saving Methods in Hydraulic Drives of Mobile Machines through the Analysis of Experimental Test Results of Hydraulic Distributors and Motors.
The study focuses on identifying effective energy-saving solutions in positive displacement hydraulic drives of mobile machines by analyzing experimental data on power losses caused by pressure drops and fluid leakage in hydraulic distributors and motors. Additionally, the study includes a comparison of methods for regulating the displacement volume in axial piston hydraulic machines and high-torque radial piston multi-cycle hydraulic motors.
The research object comprises hydraulic components, particularly hydraulic distributors and motors. Dependencies between pressure drop and flow rate in both distributors and motors, as well as fluid leakage and mechanical power losses, are analyzed based on various displacement regulation methods when comparing axial piston machines to radial piston multi-cycle hydraulic motors.
A comparative analysis was conducted on motor displacement regulation methods, including a power regulation method without altering the phase angle of fluid distribution to the pistons, and a phase-based method involving a variable number of pressurized pistons.
The study addresses the need to provide engineers and master's students with a clear understanding of how modern hydraulic component design features affect power losses and contribute to improved energy efficiency in positive displacement hydraulic drives.
Based on the analysis, explanations are provided for the observed reduction in power losses in hydraulic distributors and machines. The results highlight the promising potential of phase-based regulation methods in axial piston hydraulic machines.
The research findings are considered valuable for professionals engaged in the development of advanced hydraulic components, as well as for master's students studying subjects related to the design, development, and testing of hydraulic and pneumatic systems.

Design of a Thrust Cut-off System for Launch Vehicles with Solid Rocket Motors

2025-08-10T02:12:54+03:00

The article investigates a thrust termination system for solid-propellant vehicles motors, aimed at achieving precise shutdown of thrust without separating the vehicle’s payload section. Despite the existence of various thrust termination techniques, the influence of nozzle configuration on post-shutdown impulse and combustion stability remains insufficiently studied. The objective of the research is to minimize the residual impulse through the application of a reverse-thrust system utilizing dedicated termination nozzles mounted on the forward dome of the motor casing. To achieve this, the study analyzes nozzle geometry, flow orientation, chamber pressure before and after shutdown, and thrust coefficients for both main and termination nozzles. It is established that placing the termination nozzles at an angle of 40° relative to the motor axis and selecting an appropriate throat area enables significant reduction of post-shutdown impulse to a level that ensures stable thrust termination without degrading trajectory accuracy. This effect is attributed to the compensation of the main thrust vector by the directed reaction force produced by the termination nozzles. Unlike charge quenching or annular slit opening methods, the proposed solution does not require nozzle block displacement or injection of extinguishing agents, which simplifies the system and improves reliability. The results can be applied in the development of special-purpose vehicle systems, where structural integrity and high trajectory precision after motor burnout are critical.