Surface roughness is a critical parameter that measures the overall surface quality of a machined component. Most surface roughness measurement techniques are usually time-consuming to set up and measure, and require specialized equipment. This study proposes an alternative method for measuring the expected surface roughness on a machined component by utilizing the programming interface of a commercially available Computer-Aided Design (CAD) system. In contrast to the standard CAD models that the manufacturers provide, which usually lack critical geometrical aspects, the proposed algorithm takes into consideration the full geometry of the cutting tool, which influences the surface profile to a great extent. The CAD system utilized is a generic software, namely SolidWorks™. Specifically, the Application Programming Interface (API) and its methods were used to develop the algorithm that can simulate the kinematics of the machining process. The selected process is the external turning. Additionally, the surface profile, topography, as well as standard measurements were generated. All data were acquired with respect to typical machining parameters such as the depth of cut, feed rate, and cutting speed. Finally, to verify the accuracy of the algorithm, a set of nine cutting tests was carried out, under a widely used range of conditions, suggested by the tool manufacturer. Concluding, the experimental and the simulated measurements were compared in terms of the Ra, Rz, and Rt surface roughness values. The increased correlation percentages, exceeding 90% in most cases, proved the validity of the developed algorithm.

Ergonomics is a crucial element in industrial engineering, contributing to the optimization of production processes while ensuring safe, sustainable, and efficient working conditions. This study focuses on simulation-supported ergonomic improvements within the production system of a selected manufacturing company. The main objective was to identify ergonomic deficiencies and propose solutions to reduce workers' physical strain. A digital model of the existing workstation was created using Tecnomatix Process Simulate software, enabling detailed analysis of worker movements and postures in a virtual environment. The RULA (Rapid Upper Limb Assessment) method was applied to assess postural load before and after implementing proposed improvements. The key intervention involved introducing spring-loaded carts to reduce frequent bending and lifting during material handling. Simulation results showed a significant decrease in the risk of musculoskeletal disorders and improvement in worker posture. The study demonstrates that integrating simulation technologies with ergonomic analysis is an effective approach to enhancing workplace conditions. This method emphasizes the value of incorporating ergonomic design early in workstation planning to improve both safety and production efficiency.

It is well known that the analysis of the consequences that the interaction of the ship's body with the navigation environment has on its behaviour is one of the difficult problems of naval architecture. The responsibility of a naval architect is to develop design methodologies and building technologies that, considering the complex actions of the navigation environment, allow the efficient operation of ships, in accordance with their functionality. For ships operating in the proximity of offshore drilling platforms, more than in the case of others, it is essential to anticipate, well know and control the consequences that the navigation environment has on the general behaviour of the ship. The paper aims to make some contributions to solving the complex problem of the movements of a supply ship (understood as a rigid solid with a complex architecture) in the hydrometeorological conditions of the North Sea and Baltic Sea. The aim is to substantiate a model for the analysis of static and dynamic nautical qualities, computer-assisted by advanced software instruments (AutoHydro and Octopus Office). To exemplify the study, a supply ship built in Tulcea Shipyard was used. The authors were interested in modifying the architecture of the original hull by introducing a cylindrical portion in the stern area of the ship. This architectural choice was justified by the need to provide, on the deck, additional spaces for various equipment intended for work near the offshore drilling platforms, and, below deck, additional storage spaces for various purposes. Using the analysis facilities offered by the two software tools mentioned, the consequences that these changes have on nautical qualities have been analysed (the study exemplifies, with comments and interpretations, the hydrostatic diagram and the stability diagrams). The study was computerized by AutoHydro software for the analysis of static nautical qualities. For the analysis of the dynamic behaviour of the wave profile characteristic of the North Sea, with the help of Octopus software, the oscillatory movements of roll and pitch were analysed, both for the original hull and for the modified version. The paper aimed to support the advantages of computerized studies in the initial design phases, without minimizing the importance of tests in towing tanks or sea trials. For scenarios such as the one proposed in this paper (modification of the length of a ship already built, while maintaining the rest of the initial dimensions) the computer-aided study, with software tools specific to the field of naval engineering and navigation, highlights the following advantages: elaboration of various architectural variants, precision in design, speed in the realization of constructive solutions, simulations of the dynamic behaviour on the wave according to various parameters (draft, speed, encounter angle).

Designing machine tool bodies requires consideration of high structural stiffness, reduced mass, and stability under operational loads. This article presents a concept for a milling headstock inspired by biological structures such as the beak of a toucan and a woodpecker, which exhibit advantageous mechanical properties. The objective of the study was to develop an alternative form of the headstock body that combines lightweight construction with high stiffness, while simultaneously increasing its natural frequencies. Topological and parametric optimization methods were employed, utilizing the MOGA algorithm and finite element analysis (FEA) tools. In addition, the shape was optimized using fig and blackberry leaf models as biological analogues, refining their geometric form to ensure effective distribution of material for load transfer. The analysis of the headstock body demonstrated improved static and dynamic performance of the optimized design compared to a conventional box-type structure. The results confirm the potential of bionic design in the development of advanced machine tool components. This study highlights the importance of integrating biological inspiration with advanced engineering methodologies in the design process.

This study investigates the influence of cutting speed (V) and feed rate (f) on surface roughness average (Ra), total roughness (Rq), and mean depth of roughness (Rz) during Hard Turning (HT) and Surface Defect Machining (SDM) of AISI 4340 steel, hardened to (51 ± 1) HRC. Experiments were conducted using CBN tools using a full factorial design (4² = 16 trials) with a constant depth of cut, as per Response Surface Methodology (RSM). Identical trials were performed for both HT and SDM to enable a comparative study. Results indicate that SDM yields significantly better surface finish, improving Ra by 41.65% compared to HT. ANOVA results support a quadratic model for predicting surface roughness variations. Feed rate emerged as the most influential factor in both machining methods, whereas cutting speed showed minimal impact. Optimization of cutting parameters was achieved to minimize Ra, Rq, and Rz, enhancing surface quality and overall machining efficiency.

This investigation systematically analyzes resistance spot welding parameters optimization for AISI 316L austenitic stainless steel sheet joints utilizing an L9 orthogonal array-based Taguchi design methodology. The experimental matrix encompassed three critical process variables: welding current (6-10 kA), electrode pressure (2-6 Bar), and weld time (4-8 cycles). Metallurgical characterization was conducted through optical microscopy, facilitating comprehensive analysis of fusion zone morphology, heat-affected zone (HAZ) characteristics, and base material transformation. Signal-to-noise (S/N) ratio analysis revealed that welding current exhibited the highest statistical significance in determining joint shear strength, followed by weld time and electrode pressure. The main effects analysis revealed that the optimal parameter combination, which had a maximum tensile shear strength of 306.22 MPa, was 10 kA welding current, 2 Bar electrode pressure, and 4 cycles of weld time. In the fusion zone, microstructural analysis showed characteristic dendritic solidification patterns with secondary dendritic arm spacing that correlated negatively with mechanical characteristics and cooling rate. The study provides a strong basis for process optimization in RSW of AISI 316L stainless steel by establishing quantifiable correlations between process parameters and joint tensile shear strength.

The formability of AA6061 T6 aluminium alloy is essential due to its high strength and low ductility, posing challenges in forming processes like Incremental Sheet Forming (ISF). Annealing mitigates internal stresses, reduces material hardness, and enhances ductility, thus improving formability. This study investigates the impact of annealing cycles on the formability, microstructure, and micro-hardness of AA6061 T6 sheets during ISF. Various annealing durations (1-15 hours) were tested, followed by ISF experiments. Results demonstrate a significant formability increase with longer annealing, with nearly 40% higher fracture forming height. Micro-hardness decreases with a longer annealing duration (almost 30%), indicating material softening. Microstructural analysis reveals grain growth and recrystallisation, facilitating plastic deformation and enhancing formability. These findings provide insights into the role of annealing in improving formability and mechanical properties in ISF processes, aiding in identifying optimal annealing duration for enhanced performance.

Bi-component 3D printing technology is an important topic for researchers worldwide, as it expands the field of use of multi-material parts/parts. Such products can present varied mechanical, thermal and structural properties, from elasticity to stiffness, from stability at lower to higher temperatures, etc., thus finding their applicability for a wider range of applications compared to samples printed from a single material. A very often used 3D printing technique, due to the multiple advantages it offers, is FDM - Fused Deposition Modeling. Through 3D printing, complex interfaces can be built with a large contact surface, which gives parts greater strength and a reduced likelihood of defects by eliminating existing stresses. The choice of interface design must take into account the end use of the resulting product, as tensile, compressive, shear and flexural strength is particularly important in butt joints. This study aims to investigate the influence of the interface type on the mechanical characteristics of the printed object. This will be achieved by finite element analysis. The proposed interface types to be studied are as follows: T-shape; U-shape; swallowtail shape; mirrored inverted shape; trapezoidal teeth. According to the results obtained, the type of interface that performed the best is the T-mirror interface.

Traditional methods of machining Inconel 718 alloys using conventional cooling cause a significant decrease in tool life, so the research attempted to determine how the use of cryogenic cooling will affect the machining. The article contains the results of experimental research, the main goal of which was to determine the possibility of using DIPS dry ice cooling for machining difficult-to-machine materials. The research involved comparing of the tool life for three types of cooling system: conventional cooling with oil emulsion, cryogenic cooling with CO2 using - Dry Ice Powder System (DIPS) and CCA (Cooled Compressed Air). Inconel 718 alloy was used as the machined material. The research methodology consisted in determining tool wear curves and determining tool life for various cooling methods. Tool wear symptoms and types of chips that appeared during machining with the tested tool inserts were also compared. The tools used for the tests were SiALON KYS30 cutting inserts from Kennametal and ceramic SEC-W Whisker-reinforced cutting inserts from Genicore. The tests were carried out for rough turning. The results showed a decrease of tool life for DIPS cooling compared to oil emulsion cooling, during Inconel 718 rought turning, therefore the tests should be extented for another group of processed materials. e.g., for hardened steels, or for another cases of machining e.g. finishing turning.