Annals of ”Dunarea de Jos” University of Galati, Fascicle V, Technologies in machine building

FEM Study on the Efficiency of 3D Printed Gears

2026-01-21T08:32:35+02:00

This paper presents the 3D modeling and static structural analysis in ANSYS of a spur gear set manufactured from four different materials: two conventional steels, 36Mn5 and 18CrNiMo7 and two 3D printable Ultrafuse 17-4PH and 316L. The study aimed to compare maximum elastic deformations, Von Mises stresses, and material-specific mechanical properties in order to evaluate their suitability for gear applications. Significant differences were observed in hardness, yield strength, and wear resistance. The carburized steel 18CrNiMo7 exhibited superior strength and hardness, confirming its suitability for heavy-duty industrial transmissions, while 36Mn5 proved adequate for moderate-load applications. Among the Ultrafuse materials, 17-4PH demonstrated a favorable compromise, with acceptable ductility and the potential for post-printing heat treatment, making it suitable for functional prototypes and gears with moderate loads. The analysis concludes that while Ultrafuse materials can be effectively employed in prototyping and testing, carburized steel 18CrNiMo7 remains the recommended choice for industrial series production of gears subjected to high loads and wear.

Flowchart Identification in the Case of Maintenance Process Management

2026-01-21T08:32:38+02:00

The implementation of an integrated management system in industrial companies involves the identification of the processes needed and associated performance indicators. The complete and correct definition of performance indicators plays an important role in both process performance monitoring and impact of the process on the company results identifying. Considering the maintenance of the machine-tools as one of the main support processes for manufacturing, it is important to analyze, identify and solve the maintenance problems as fast as possible. The definition and implementation of maintenance programs, which request some resources is needed to prevent the machine-tools downtime. Taking into consideration the importance of machine-tools availability, it is necessary to define and validate a method for data collecting and analyzing the machine-tools’ performance in terms of available time usage. In the present paper, a case study is conducted using a database including data collected from industrial environment, in the case of the manufacturing process of bearing components. An integrative method for the identification, control and optimization of the total defect time was defined and validated with the main purpose of identifying the flowchart for collecting, analyzing, and database updating.

Recent Advances and Environmental Considerations in Brake Disc Material Development

2026-01-21T08:32:38+02:00

Brake discs operate under extreme thermal, mechanical, and chemical stresses, requiring materials that balance durability, braking efficiency, cost, and environmental impact. This paper reviews recent developments in grey cast iron, titanium alloys, and ceramic–matrix composites, along with surface coatings, cryogenic treatments, and design-based thermal management. Improvements in material microstructure, surface engineering, and rotor geometry have improved wear resistance, heat dissipation, and overall braking stability. Growing environmental concerns are encouraging the adoption of cleaner, more sustainable materials and designs that reduce particulate emissions and prolong component lifespan.

A Review of CNC Machine Tool Types, Applications and Programming Approaches

2026-01-21T08:32:39+02:00

This review paper delves into the evolution, capabilities, and practical applications of CNC machines, which have revolutionized the field of mechanical processing. The paper provides an in-depth analysis of various types of CNC machines, including milling, turning, and multi-axis systems, highlighting their adaptability and efficiency in performing complex machining tasks. It presents the fundamental principles of mechanical machining and it also explores key aspects of CNC machine programming, emphasizing the significant role of ESPRIT TNG software in optimizing processing workflows. This advanced software enables intuitive and flexible CNC programming, providing users with powerful tools for simulation and G-code generation. This software offers comprehensive capabilities for simulation, toolpath generation, and seamless integration into diverse manufacturing environments. By integrating technical information this paper aims to become a valuable resource for both specialists and beginners in this domain. The focus is placed on knowledge transfer and fostering innovation in computer-assisted mechanical processing.

Investigation of the Clinching Process Under Variable Forming Speeds Using Finite Element Modelling and Post-Joint Extraction Analysis

2026-01-21T08:32:39+02:00

This study investigates the clinching joining process at different forming speeds using Finite Element Method (FEM) simulations. The objective is to analyze how process velocity influences material flow, stress distribution, deformation behavior, and final joint geometry. A numerical model was developed to replicate the clinching process, enabling the extraction of relevant mechanical characteristics such as local strain accumulation, contact pressure profiles, and residual stress fields in the joint region. The resulting clinched connections were further subjected to a simulated pull-out test to evaluate joint strength and separation behavior. Force–displacement curves were generated to quantify the extraction forces under different joining conditions, with particular attention to peak force levels and the onset of structural failure mechanisms. The data obtained provide insight into the correlation between forming speed and structural integrity of clinched joints. The outcomes of the research contribute to a deeper understanding of process parameters governing clinching, facilitating improved design and optimization of mechanically formed joints in thin-sheet applications.

A Review of Image Processing for Detecting and Analysing Transmission Error in Gears

2026-01-21T08:32:40+02:00

Transmission error (TE) of gear pairs is the main cause of gear vibration and noise. Over the last years, non-contact optical and vision-based techniques have developed in conjunction with present image processing, point cloud analysis, and machine learning to enable direct, high-resolution assessment of tooth profiles and surfaces appropriate for TE estimates and diagnostic monitoring. Acquisition modalities, image processing pipelines, mathematical techniques for TE computation or profile extraction, and validation criteria are all summarised in this paper.

Finite Element Analysis of The Deep Drawing Process of Magnesium Sheets

2026-01-21T08:32:40+02:00

This study presents a finite element simulaation of the deep drawing process applied to a 2-mm thick magnesium sheet using Simufact Forming. The forming operation was investigated under four different punch velocities, 10 mm/s, 20 mm/s, and 30 mm/s, to assess the influence of deformation speed on material response. The numerical results revealed distinct differences in stress distribution, effective plastic strain, and deformation pattern as a function of forming velocity. The simulations also produced force evolution curves along the Z direction, which demonstrated clear correlations between forming speed and required forming load. At lower speeds, material flow was more homogeneous with smoother strain gradients, whereas higher forming speeds resulted in intensified stress concentrations and more localized deformation. The analysis provides insight into the strain-rate-sensitive forming behavior of magnesium sheets and supports the selection of optimal forming conditions for improved manufacturability in lightweight structural applications.

Identification of The Flowchart for Manufacturing and Inspection of Industrial Spare Parts

2026-01-21T08:32:40+02:00

In the actual development of technologies and related devices it becomes important to develop the manufacturing processes considering the integration of the main factors concerning the technological steps, inspection steps and reaction plan in the case of non-conforming parts. To optimize the manufacturing steps, the flowcharts should give a theoretical overview of the production and inspection processes and the correlation between them. In the present paper the application of a tool used in the automotive industry is proposed for sampling in the case of a fastening lug. During the development phase, activities for manufacturing steps identification and the related inspection methods were determined. Also, the reaction plan was identified in the case when a non-conforming part resulted from processing. In the development phase of a product, one of the most important jobs of a process designer is to integrate, in a suitable manner, in the same flowchart, the main requirements regarding the products process, inspection and cost saving. The defined flowchart was implemented in the case of an industrial spare part used in fixing devices, by considering two different variants. A comparison between the results obtained was made. Both proposed alternatives were validated, so they can be used in practice.

Joining Methods for Aluminium Sheets

2026-01-21T08:32:41+02:00

Aluminium and its alloys can be joined using various mechanical methods, by adhesive bonding, by welding, or through hybrid (combined) methods. This paper briefly presents methods for joining sheets and flat bars with overlapping edges, including traditional methods such as riveting, resistance spot welding, and cold spot welding, as well as more recent techniques such as cold welding on cogged edges, self-piercing riveting, hybrid joining by welding and self-piercing riveting, and cold spot welding with an interlayer, developed in our laboratories.

Analysis of the Functionality of a Linear Hydraulic Motor in a Low-Pressure Hydrostatic System

2026-01-21T08:32:41+02:00

The document proposes the analysis and design of a low-pressure hydrostatic drive system, an area of interest from the perspective of resource optimization and technological performance improvement, with reference to the analysis of the functionality of a linear hydraulic motor.

The way of fluids transfer energy is examined, with an emphasis on essential hydrostatic calculations such as determining transmitted speeds and forces. These principles will form the basis for simulations performed using OMEGON Fluid software, which will facilitate the visualization and optimization of assembly diagrams.

Another main aspect is the design and analysis of a linear hydraulic motor, using CAD tools and FEM methods, studying the mechanical behavior of the motor, identifying how stress and deformations are distributed under load.

Geometric Characterization and Parameters Selection of Gielis Superformula-Based Pitch Curves for Undercut-Free Noncircular Gears Design

2026-01-21T08:32:41+02:00

The paper is concerned with the insertion of the Gielis’ supershape in the non-circular gears’ theory, by selecting a subset of the modified elliptical shapes to define the pitch curve of the driving gear. A one-factor-at-a-time sensitivity analysis enables a proper selection of the Gielis’ supershape defining parameters, to achieve convex shapes, with maximum curvature limited by the undercutting phenomenon occurring during gear manufacture. A simulation of the gear’s teeth generation wherein a pinion-type shaper cutter serves as a cutting tool, enable to illustrate the tooth flank profile geometry, as a graphical validation of the developed analysis. Manipulating the driving pitch curve geometry, through the Gielis’ superformula parameters, the transmission ratio variation can be easily achieved.

Structural Calculation, Lubricant Consumption and FEM Modeling For 7211 BE and NUP 211 EC Bearings

2026-01-21T08:32:41+02:00

In the machine building industry, the reliability and performance of mechanical systems, including bearings, directly depend on the quality and efficiency of lubrication.

The paper aims to evaluate the behavior of lubricants under specific operating conditions, dealing with the principles of calculating their consumption and highlighting calculation, simulation and testing methods relevant to bearings. It also addresses several criteria for selecting lubricants, lubrication systems and relubrication intervals, as well as the programming of their use in the industrial environment.

By modeling and analyzing FEM (Finite Element Method) bearings incorporated in real mechanical assemblies, the effects of various types of lubricants on the distribution of stresses, deformations and durability over time are investigated. The aim is to provide an applicative vision on how lubrication contributes to increasing the service life of components, reducing maintenance costs and improving the energy performance of bearings.