This paper investigates the effect of a major overhaul on the positioning accuracy and repeatability of a KUKA KR6 R900 industrial robot. The robot has been used extensively for teaching and programming activities, during which occasional collisions and long-term mechanical wear may have affected its positioning performance. To assess the changes resulting from the overhaul, experimental measurements we (…)
The abrasive blasting process is designed for blasting structurally complex components or structures. The target of blasting is to achieve an optimal surface finish on structures, for example, prior to the application of an anti-corrosion coating. The effectiveness of abrasive blasting technology is highly sensitive to the settings of key operating conditions, which include air pressure and air flow rat (…)
This study examines the mechanical behaviour and ballistic performance of Twaron CT 737 para-aramid/epoxy laminates manufactured by vacuum-assisted resin transfer moulding, with particular emphasis on damage development across different structural scales. Tensile, three-point flexural, and Shore D hardness tests were complemented by ballistic experiments using 9 × 19 mm full metal jacket (FMJ) ammunitio (…)
This study examines the effect of annealing on the mechanical properties, deformation behaviour, and fracture mechanisms of PETG specimens fabricated using Fused Deposition Modelling (FDM). Samples with infill densities of 25%, 50%, 75%, and 100% were subjected to thermal treatment at 90°C, 100°C, and 110°C, followed by controlled cooling conditions. Mechanical performance was evaluated using tensile te (…)
This article focuses on the application of ultra-low-carbon martensitic high-strength M300 maraging steel in the field of with emphasis on defence industry applications and machine gun components. Main aim of this article is analysing the effect of different heat treatment regimes, in particular solution annealing and precipitation hardening (aging), on the results of nanohardness and reduced elastic mo (…)
This study examines the correlation between progressive flank wear and chip formation mechanics dur-ing high-feed milling (HFM) of DIN 1.2343 tool steel. The research compares length-based and weight-based methods for determining the chip compression ratio and shear plane angle ϕ, evaluating their sensitivity to tool degradation. Reaching the tool life limit is associated with a decreased angle ϕ, incre (…)
This study presents a comprehensive analysis of dissimilar lap joints made of S235JR (4 mm) and S355MC (3 mm) structural steels using G3Si1 (1 mm) filler wire. Welding was performed using the MAG (Metal Active Gas) process in CMT (Cold Metal Transfer) mode. Four specimens were welded with different heat inputs (Q) from 0.4 to 0.6 kJ/mm. The welding parameters had a significant effect on the weld geometr (…)
Thermal properties are key parameters in many industrial processes involving particulate materials, yet their determination remains challenging due to the heterogeneous nature of bulk solids. This study presents an experimental method and laboratory device for evaluating thermal conductivity under controlled heating conditions. The setup is based on unidirectional heat conduction and determines relative (…)
This work examined and showcases the change in wettability of motor oils in relation to their degradation and treatment of the surface they wet. Wettability is a complex scientific discipline which focuses on the interplay of a liquid placed upon a surface, their surrounding atmosphere, their „compatibility“, and their properties. Over 485 measurements were done, using the sessile drop method, to furthe (…)
The paper focuses on summarizing the application possibilities of composite materials with natural reinforcements and bioplastic matrices in the automotive. The first section describes composite materials with natural reinforcements and the key reasons for their use. Within the text, the abbreviation NFRB-P is introduced to distinguish composite materials with a bioplastic matrix and natural reinforceme (…)
Machining thin-walled components often suffers from dynamic instabilities like chatter due to low structural rigidity. While cryogenic support structures formed by expanding liquid CO₂ and a lubricant provide a promising stabilisation method, they introduce complex dynamic trade-offs. Specifically, sub-zero temperatures elevate workpiece material strength, leading to higher process excitation forces. Co (…)
High-Feed Milling (HFM) is a highly productive method for machining tool steels. However, selecting the optimal cutting environment remains a critical factor for ensuring tool life and energy efficiency. This study compares five different cooling strategies – dry machining, conventional external fluid cooling, high-pressure internal fluid cooling, cooling via compressed air through the spindle, and exte (…)
This paper presents the identification of a multilinear isotropic hardening material model for PETG produced by fused filament fabrication (FFF) using a noncontact computer vision extensometer. A tensile test was performed on flat specimens with surface line markers, and the marker displacements were measured without contact by tracking them in recorded images. Strain was calculated from these displacem (…)
The aim of this study is to investigate the application of deep Echo State Networks (DeepESN) combined with wavelet decomposition for short-term forecasting of daily natural gas consumption in a building. The proposed approach includes extracting the temperature-related component using linear regression, wavelet decomposition of the residual signal, and independent forecasting of the resulting component (…)
An ultrasonically generated pulsating water jet (UPWJ) can be produced by the action of an ultrasonic sonotrode on a liquid in an acoustic pressure chamber, whereby its acoustic action may affect the resulting outflow velocity. This study presents a theoretical approach to estimating the peak UPWJ outflow velocity that, in addition to hydraulic pressure, accounts for the possible acoustic contribution o (…)
This paper numerically compares the axial stiffness and local stress of three BCC lattice specimens under compression. The intact REF model is compared with the INT and SIDE models, which have one missing internal strut and one missing strut near a lateral surface, respectively. All variants use the same linear elastic structural steel model, end plates, and prescribed axial displacement of 0.01 mm. Cal (…)
The rapid emergence of the Low-Altitude Economy (LAE) is transforming unmanned aerial vehicles (UAVs) from experimental research platforms into practical carriers of parcels, medical supplies, and sensor data at altitudes below approximately 1000 m. Urban airspace and complex mountain terrain remain among the most demanding operational environments for autonomous UAV control, because flight trajectories (…)
Surface roughness is one of the main quality indicators and often a technical requirement specified for mechanical components, where achieving the proper surface quality is crucial for part functionality. In actual machining, surface roughness is influenced by numerous factors, including cutting parameters, tool variables, and workpiece variables. One of the key factors affecting surface roughness and c (…)
This article presents the design and implementation of a software-based IoT monitoring system with interactive data visualization. The system simulates a pneumatic piston controlled by a virtual PLC server, transmits process variables through the OPC UA communication protocol, and displays real-time and historical data through a web interface. The backend is implemented in Python using FastAPI library; (…)
The vibration-oriented optimization of cyclically symmetric bladed structures subjected to aerodynamic excitation remains computationally demanding because conventional strategies typically require repeated harmonic response analyses throughout the optimization process. Controlled modifications of blade geometry, mass or stiffness can reduce critical resonant responses; however, the most favourable modi (…)
This paper presents an innovative mathematical modelling paradigm for intelligent CNC machine tools based on the Steiner Roman surface as a geometric core of digital twins. The use of this topological abstraction is investigated for analytical determination of the cutter-workpiece engagement (CWE) zone during multi-axis milling of free-form surfaces. An approach for detecting kinematic singularities and (…)
This study evaluates a positioning method using multiple hole-and-pin sets to improve assembly accuracy by decreasing "assembly shift" caused by clearance fits. While typical two hole-and-pin configurations are standard, they often introduce undesirable assembly shift due to necessary clearances. Although prior research has addressed translational assembly shift suppression, the impact of multiple sets (…)
Thermographic diagnostics serve as an important tool for monitoring thermal processes and identifying potential operational deficiencies in industrial equipment. This method enables non-contact measurement of temperature distribution on object surfaces, analysis of heat transfer, and the detection of thermal anomalies that may indicate functional malfunctions or excessive thermal stress on individual co (…)
Porosity is one of the significant internal defects of pressure castings and can negatively affect their mechanical properties. One of the methods for reducing the amount of air and gases trapped in the die cavity during filling is die vacuuming. This study aims to experimentally evaluate the effect of die vacuuming on the porosity of pressure castings. The experiment was carried out on a CLH 250 horizo (…)
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