ACTA TECHNICA NAPOCENSIS - Series: APPLIED MATHEMATICS, MECHANICS, and ENGINEERING
History of the Journal Beginning with no. 35/1992, of the scientific Bulletin of the Cluj-Napoca Polytechnic Institute, edited since 1958, will continue to appear under the new name ACTA TECHNICA NAPOCENSIS, Technical University of Cluj-Napoca. This message has appeared in Romanian and in English by the year 2002, on the same page with the College editorial office. The magazine enjoys a good name and good reputation has a both in country and abroad, as seen from the list of works and of Xerox copies of the file. I WILL PASS THE PERIODICITY AND THE NAME ACCORDING TO THE RECORDS OF THE LIBRARY OF UTCN: SCIENTIFIC BULLETIN, SERIES: MATHEMATICS-PHYSICS-MECHANICS APPLIED, 1977-1979 BUILDING CONSTRUCTION MACHINERY 1979-1982 MATEAMATICA-APPLIED MECHANICS-CONSTRUCTION MACHINES 1983 – 1989 APPLIED MATHEMATICS MECHANICS 1990 – 1991 ACTA TECHNICA NAPOCENSIS SERIES: APPLIED MATHEMATICS AND MECHANICS 1992 to CONTINUE Since 1992 the scientific Bulletin of IPCN was divided into 4 separate magazines, each has a name and serial number ISSN assigned, with an Editor of the series. One of these represents ACTA TECHNICA NAPOCENSIS, Sesies: Applied Mathematics and Mechanics, ISSN 1221 – 5872, series editor: Prof. Dr. IOng. Mariana ARGHIR, being unchanged since 1992. Each article has a summary in English, French or German, and at the end of each article is article title and summary in English, and finally it has a title and an abstract in Romanian. In 2007 the magazine was named by CNCSIS in category B, the situation in which the magazine has its own web page, and in 2009 became class B +, with registration in the database world COPERNICUS. The fields are: 1A Mathematics; 1B Informatics; 2A Mechanical engineering; 2F Industrial engineering The Code Commission: 2. Commission for Science Engineering
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APPLICATION OF MACHINE LEARNING TECHNIQUES FOR MODELING THE REACTOR OF THE CATALYTIC CRACKING PROCESS
This paper presents the research and results obtained by authors regarding the modeling of the reactor of the fluid catalytic cracking unit (FCCU), using various machine learning techniques based on supervised learning algorithms Compared with the analytic mathematic modeling methods, machine learning techniques (ML) can solve the difficulties in FCC process modeling, such as strong correlation between variables, nonlinearities, the complexity of kinetic models, and feedstock complexity. The ML method establishes a mathematical correlation between the input and output variables of the process using industrial data. Five supervised learning machine methods are used to model the reactor: random forest regression (RFR), decision trees regression (DTR), k-nearest neighbors (KNN), support vector machines (SVM) and gradient boosting regression (GBR).
COLLABORATIVE ROBOTICS: CASE STUDY, OPPORTUNITY AND CHALLENGES
The technological advances emerging with Industry 5.0 and the difficulties of maintaining flexibility and competitiveness are pushing companies towards new work scenarios that involve the use of collaborative robots. However, such developments are throwing up new challenges in terms of occupational health/safety. the purpose of this paper is to present real case feedback and associated challenges related with collaborative robots as well as different tools and methods to face it. The presented results show that cobots are still at the “test level” and their design must overtake the internal contradiction in the human (variability)-robot (invariant) system. Different tools and methods are proposed such as VR or usage method. The new challenges need to be undertaken by considering new knowledge and preventive measures. This is vital for employee health and overall business success.
INNOVATIVE REPRESENTATION OF DOUBLE ORTHOGRAPHIC PROJECTION USING 3D PRINTING TECHNOLOGY
This paper discusses how to use 3D printing to exhibit double orthographic projection and actualize a functional, didactic physical model using FDM technology. Two articulated plates enable positioning at a 90° angle and folding into a common plane, effectively illustrating geometric projections. Flexible cylinders and a sphere symbolize the geometric point, facilitating the analysis of its position relative to projection planes. A spotlight enhances projection visibility and supports better visual understanding. The optimized technical parameters, such as temperature, print speed and the height of the deposited layer, ensured the accuracy of the obtained components. Results confirm the efficiency of 3D printing in clarifying descriptive geometry principles and developing an interactive and precise educational tool.
USE OF AI LANGUAGE MODELS IN GENERATING 3D PRINTABLE MODELS
This paper presents aspects regarding the integration of artificial intelligence (IA) with OpenScad to generate STL files used in 3D printing. Conventional CAD modeling and manual writing of parametric scripts often require advanced technical knowledge and are prone to errors. It simplifies this process by interpreting the instructions in natural language and the automatic generation of optimized Openscad scripts. The experimental study focused on the design of a grooved tree-functional bore system, demonstrating the ability to ensure geometric accuracy, functional adaptability and perfect integration in the sectioning software. The results obtained confirm the efficiency, reproducibility and flexibility in the design, positioning as a transforming tool in parametric workflows for 3D printing.
3D DESIGN TECHNIQUE TO REDUCE REDESIGN TIMING
The current industry imposes a dynamic market in which the requirements are no longer clear from the first phases of project development, so the designed products require improvements and changes that sometimes totally change the appearance of the products. The present paper proposes a case study on a 3D design technique to reduce the time and costs of redesigning. Using the basic skeleton technique, designers build a parameterized system on which they build the 3D model. The technique is part of the top-down -based product design concept and is often mandatory in the 3D design of products. This paper proposes an ECU module product designed in the Catia V5 R16 design software as example to evaluate the impact on development costs and times. The study resulted in a significant reduction in research and development effort and costs.
INFLUENCE OF CUTTING PARAMETERS ON SURFACE QUALITY OF AL7075 ALLOY UNDER DRY AND LN2 COOLING CONDITIONS
The aim of the present paper was to investigate the influence of cutting parameter under dry and LN2 (liquid nitrogen cooling) cooling condition on surface quality. Experiments were conducted on the AL7075 aluminum alloy and three cutting speeds and two cutting depths were tested in the presence and the absence of the cryogenic cooling. The increase of cutting speeds under the cryogenic cooling conditions led to a decrease of surface roughness from 0.28 µm (in dry condition) to 0.16µm (with LN2 cooling). Similar behavior was observed in the case of the increase of the cutting depth, thus for higher cutting depths the use of cryogenic cooling liquid generated lower surface roughness values that the dry milling. In conclusion the use of the cryogenic cooling technique is recommended for AL7075 milling as it generated better results that the dry machining and it is also considered an environmentally friendly technique.
POSTPONING DEEP DOCUMENTATION TO GENERATE INNOVATIVE SOLUTIONS
Ensuring the competitiveness of products and technologies requires addressing innovation activities. The didactic work of the authors of this paper has led to the observation that, under certain circumstances, a deep documentation activity when aiming to identify innovative solutions can turn into a psychological obstacle in terms of generating innovative solutions in a given time. One way to reduce such a consequence of deep documentation can be to postpone it, that is, resort to extensive documentation only after identifying at least one supposedly innovative solution. However, one cannot give up on deep documentation, which is necessary to validate the innovative nature of the identified solution and the possibilities of its use. Postponing deep documentation can be applied when there is a certain level of professional knowledge. Arguments and explanations have been formulated according to which, at least in certain situations, a postponement of deep documentation may be indicated.
ANALYSIS OF CAVITATION PHENOMENON AS A CRITERION FOR OPTIMIZATION OF CENTRIFUGAL PUMP DESIGN
In the given paper, the problems of describing the cavitation process by means of CFD methods are presented. The role of cavitation process study as an optimization criterion of centrifugal pump construction is also described. At the same time the theoretical part related to modeling the cavitation process in centrifugal pumps is discussed. At the end of the paper, the process of determining the NSPH value by means of CFD simulations and comparison of the results with the results of physical testing of a serial pump produced by CRIS Hermetic Pumps is presented.
SHEET METAL ASSEMBLY DESIGN METHODS ANALYSIS
This paper analyzes some design methods (from simple to complex) regarding time and problems encountered. The aim is to quantify the advantages of parametrized design based on parameters, relations, and design switches, either using solid activation/deactivation or profile switch. Deactivation of features is not recommended as it could lead to errors later on. This study is meant to find a way to avoid the method of feature deactivation, use the curve parameter type instead and check the method's failure possibilities. The results reveal the success of the method and its limitations in SMD. The curve parameter method seems robust mostly when used in PD and GSD.
MULTI-OBJECTIVE OPTIMIZATION OF LASER ENGRAVING PARAMETERS USING GREY RELATIONAL ANALYSIS
Laser engraving is an advanced technique for precise application of markings on the surface of molds, offering advantages such as high accuracy, wear resistance, execution speed and the ability to mark complex surfaces. This environmentally friendly method ensures good long-term readability without the use of chemicals. The study presents multi-objective optimization of engraving parameters, using experimental design and gray relational analysis to simultaneously improve surface roughness, engraving depth and processing time. By analyzing seven input parameters, the research identified the optimal settings and the factors with the greatest influence on the process, demonstrating the effectiveness of the method and opening new perspectives for improving the process performance.
STUDY OF THE CUTTING FORCES АND QUАLITY PАRАMETERS OF THIN-WАLLED PАRTS MАCHINED BY MILLING
The study in this pаper аims to аnаlyze the effect of two factors (i.e., feed rаte аnd cutting speed) on cutting force аnd two quаlity pаrаmeters of pаrts (residuаl stresses in the surfаce lаyer аnd surfаce roughness) when milling thin-wаlled pаrts. It wаs found thаt increаsing cutting speed аnd feed rаte usuаlly cаuses аn increаse in cutting force аs well аs surfаce roughness аnd residuаl stresses. The meаsured residuаl stresses were аll of the compressive stress types.
SOFTWARE TOOL FOR DETERMINING OF METAL MILLING PARAMETERS
This paper presents an original software tool for the calculation of cutting parameters in metal milling, named Determining Milling Parameters (DetMilP). Developed in the RAD Studio programming environment, this software tool calculates cutting parameters and provides the user predictions about the process. Additionally, it allows the creation and management of a database for cutting tools, the search and insertion of tool parameters from various suppliers through an adapted search engine. The software also has the facility to launch ChatGPT to provide the users a quick technical support. The results of the calculations can be exported as a report or text file. The text file can be imported into the CAM module of the Creo software, facilitating the direct use of calculated parameters in CNC programs.
PRODUCT CONFIGURATION FOR MASS PERSONALIZATION
In mass personalization, the customer is integrated into the product design process during the configuration phase. The paper presents different strategies and approaches to product configuration, the integration of product and process configurations, product configuration systems that satisfy customers, ensuring production efficiency, and mass customization. An attribute/function-based configurator is proposed that integrates process, product configuration, and process planning decisions. It was also proposed that an open architecture product configurator be developed to integrate both a customer interface and an application used by engineers involved in product design.
IMPROVING THE FUNCTIONAL TESTING PROCESS BY APPLYING THE 6 SIGMA METHODOLOGY IN THE AUTOMOTIVE FIELD
The article describes the benefits of using the Six Sigma DMAIC cycle to enhance delivery timing to clients in the automotive industry. The DMAIC cycle tools were used at each stage, and each consecutive step was built on the results of the preceding one, with the goal of achieving a long-term solution to the examined issue through the deployment of corrective actions. The use of corrective actions resulted in improvements, eliminating the waste in the assessed organization. The root cause was a lack of information between the teams, which resulted in waste. The solution for this challenge was to strengthen collaboration with other teams while creating papers for upcoming tests based on their duration and difficulty.
PARAMETRIC MODELLING OF INVOLUTE GEARS WITH CURVILINEAR SHAPED TEETH
Gears are mechanical components used in various industrial applications. They ensure a constant transmission ratio and efficient operation at different speeds and power levels. The 3D modeling of gears with curved teeth allows design optimization, reducing noise and vibrations, as well as cost reduction through virtual testing and the minimization of manufacturing errors by integrating CNC processes and 3D printing. The article presents the parametric design of cylindrical gears with curved teeth with epicycloidal flanks. Using the parametric equations of the epicycloid and involute, calculation programs were developed to determine points on the flanks. These points were used in CAD software to obtain the 3D model, which allowed the observation of the theoretical position of the contact area.
RESEARCH ON THE NUMERICAL MODELING OF THE INCREMENTAL PLASTIC DEFORMATION PROCESS USING A HEMISPHERICAL TOOL
This study presents the numerical modeling of incremental plastic deformation using a hemispherical tool on AA6061 aluminum alloy. A finite element model was developed in ABAQUS, using the explicit method. The thermo-mechanical behavior of the material was defined by the Johnson-Cook law, the modeling of thermal phenomena was based on an adiabatic approach, and the simulation time was reduced by using mass scaling. Validation, based on comparing the simulation results with experimental deformation forces and temperatures, revealed similar trends, although some differences in the maximum values appeared due to modeling assumptions. The analysis of deformation forces, temperatures, 3D shape evolution and plastic equivalent strain provided key information on the SPIF process. Key points identified include the onset of plastic deformation, stabilization of forces, and temperature during the process.
SIZE AND BUILD ORIENTATION EFFECT ON THE TENSILE PROPERTIES OF POLYMERS MANUFACTURED THROUGH STEREOLITHOGRAPHY
This study aims to investigate the geometry scale effect and printing orientation on the tensile properties of common photosensitive resins produced via stereolithography (SLA). Through tensile tests, the research evaluates how variations in part size and orientation on the build-platform influence mechanical performance, with a particular focus on challenges in scaling SLA technology for practical applications. By analyzing the interaction between printing parameters relative to tensile forces and resulting mechanical properties, this study provides insights into optimizing SLA processes for enhanced tensile strength and stiffness. The results contribute to understanding how SLA can evolve from prototyping to reliable production of functional parts, offering supplementary insights in additive manufacturing.
ARCHITECTURE PROPOSAL FOR IMPLEMENTATION OF ARTIFICIAL INTELLIGENCE ON CNC MACHINE TOOLS
Today, the emergence of new industrial values and the integration of advanced technologies have ushered in a significant evolution in industry through the implementation of Industry 4.0 strategies. As Taylor noted in 1911, a production system must be analyzed starting from its elementary processes. Building on this idea, this paper proposes a control system with artificial intelligence at a foundational level of production systems, specifically focusing on CNC machine tools. Two types of artificial intelligence control systems are proposed for manufacturing processes: one aimed at increasing processing accuracy and the other designed to reduce processing costs or enhance productivity
WAVELET SYSTEM FOR INTELLIGENT MEASURING, DESIGNED TO ENHANCE THE MANUFACTURING PROCESS OF A PHOTOVOLTAIC MODULE. PRELIMINARY RESULTS
Intelligent measuring is related to smart systems and automated measurements of weather conditions or solar irradiance, to help the manufacturer to optimize solar cell features. Technology should strive to minimize the impact of human activity upon the environment, developing greener solutions for energy consumption. In this paper, we propose a prototype for a wavelet based system, which should analyze several parameters collected by a photovoltaic system - using the Stationary Wavelet Transform. We aim to develop a general mathematical model, which should allow us to improve the manufacturing process of the solar modules. The Stationary Wavelet Transform and several mother wavelets families were tested. The most accurate results were obtained with the Daubechies mother wavelets.
NUMERICAL SIMULATION OF DISSIMILAR FRICTION STIR WELDING OF ALUMINUM ALLOYS AA7075 AND AA2024: INFLUENCE OF TOOL GEOMETRY ON TEMPERATURE DISTRIBUTION
Friction Stir Welding (FSW) is an innovative joining process widely applied for aluminum alloys, offering low-cost and efficient solutions for complex industrial applications. This study focuses on welding dissimilar aluminum alloys AA7075 and AA2024, emphasizing the importance of temperature control and the influence of tool geometry on the process. Numerical modeling was performed Abaqus software to simulate the thermal behavior during welding and analyze key parameters such as pin profile and coefficient of friction. The results reveal that the cylindrical threaded pin generates moderate temperatures, making it most suitable for welding these alloys, while the square pin produces higher temperatures, posing a risk of overheating, particularly for AA7075. In contrast, conical and cylindrical pins generate insufficient heat for effective joint formation. This research highlights the value of numerical simulations in optimizing FSW parameters for defect-free joints in dissimilar aluminum alloys.
CONSIDERATIONS ABOUT COST ESTIMATES IN PRODUCT DESIGN OF A CUTTING TOOL
In the project management of new product development, the cost estimates of a project are directly influenced by the scope of the project. In product development, the scope of a project is the finished product. Unless the new product is a combination of existing sub-components for which the costs are known, a decomposition of an unknown product is necessary in order to form the estimates. A quick and easy method for cost estimation will be investigated involving the use of Axiomatic Design method applied to a custom design milling machine. The results confirm the utility of the method in cost estimation of a new product.
STUDIES ON THE DESIGN AND PERFORMANCE OF A MAGNETIC PLANETARY GEAR
Magnetic gears are innovative devices that emulate the functionality of traditional mechanical gears using magnetic fields instead of physical contact between teeth. The subject of our concerns is the study of the performances and design elements for a planetary magnetic gear. The originality of the proposed magnetic gear lies in the fact that the arrangement of the gears and the geometric shape of the teeth allow, at the limit, mechanical engagement. The problem that arises is to determine as precisely as possible the torque capable of being transmitted at the level of two teeth and then by extrapolation, the torque capable at the level of the planetary magnetic gear can be determined.
SUSTAINABILITY IN ENGINEERING. EVALUATION OF THE MECHANICAL BEHAVIOR OF POLYOXYMETHYLENE THROUGH REPEATED INJECTION CYCLES
The increasing global production of plastics raises sustainability challenges and underscores the necessity of transitioning to a circular economy. This study evaluates the mechanical behavior of polyoxymethylene (POM) after multiple mechanical recycling cycles to determine its potential for reuse in industrial applications. The research involved the initial injection of POM specimens, followed by successive grinding and reinjection over ten cycles. The analyzed mechanical properties included tensile strength, maximum tensile force, elongation at break, and Young’s modulus. Results indicate a gradual decrease in tensile strength (4.1%) and elongation at break (29.7%), while Young’s modulus remains stable. The study confirms the feasibility of mechanical recycling of POM for non-critical structural applications, with recommendations to limit recycling cycles or blend recycled material with virgin polymer to mitigate property degradation.
THE USE OF HIERARCHICAL MODELS WITH COLORED PETRI NETS IN THE STUDY OF ROBOTIC MANUFACTURING PERFORMANCE
This paper is a study through which robotic manufacturing cells can be modeled using hierarchical Petri nets. They are an efficient tool due to their ability to model dynamic processes. The subject addressed in the paper is that of modeling and improving the manufacturing workflow for the pipe bending process. Within the research carried out, three models are compared with Petri nets made in the CPN IDE program with the aim of improving the system. The first model represents the initial production flow. The second model improves the sequence of robot movements by introducing additional tasks to the robot serving the production process. The third model introduces a double clamping system, allowing the simultaneous manipulation of two pipes, which leads to a significant increase in productivity. The streamlining of the workflow and improvement of resource use are confirmed by the simulation results.
THE IMPLEMENTATION OF A DECISION-MAKING SYSTEM BASED ON FUZZY LOGIC FOR OPTIMIZING PRODUCTION SCHEDULING OF PLASTIC PARTS MANUFACTURED BY INJECTION MOLDING
This paper presents the development of a user interface for a fuzzy logic decision-making system designed to optimize production scheduling in the injection molding industry. The system integrates input variables such as production time, due date, the client negotiation possibility, project complexity, safety stock and profit rate, to dynamically determine order priorities. The user interface enables intuitive interaction, allowing users to provide real-time data as input and visualize the output. By using fuzzy logic, the system can overcome uncertainties, which are common in production environments, enhancing scheduling efficiency and decision-making accuracy. The interface simplifies the interpretation of complex data, ensuring better utilization of resources and adherence to deadlines, resulting in an improved operational performance.
STANDARDS TAXONOMY SUPPORTING MANUFACTURING IN INDUSTRY 4.0 TOWARD 5.0
The article presents the approach of a taxonomy development with standards providing support to technologists and designers in manufacturing to better manage production processes. The approach is intended to consider the current manufacturing framework marked by the transition from Industry 4.0 to Industry 5.0; the taxonomy framework design approach consists of eight steps: (1) defining the scope, (2) conducting literature reviews, (3) collecting data, (4) conceptualizing the basic items, (5-8) documenting, classifying, validating, refining and maintaining the created database. Consulting various specialists during the testing and validation phase of the taxonomy highlighted the usefulness of the approach and its result in facilitating the process of navigating the complexity of standard aspects related to smart manufacturing, to boost innovation and compliance.
EVALUATING 3D PRINTING AS A PERFORMANCE-DRIVEN ALTERNATIVE IN MEDICAL RECONSTRUCTIONS
3D printing is changing the way medical devices are made, offering new possibilities for customization and material efficiency. However, traditional manufacturing methods, such as milling and casting, are still widely used due to their proven reliability and strong mechanical properties. This paper compares these two approaches by looking at key factors such as structural integrity, mechanical performance, and cost-effectiveness. We focus on medical applications, including patient-specific fixation plates, re-movable dentures, and zirconia dental restorations. The results show that while 3D printing allows highly customized solutions and efficient material usage, conventional manufacturing remains the bet-ter choice for certain applications requiring high mechanical strength. Our analysis highlights the strengths and weaknesses of each method, providing insights into when and where each approach is most effective.
EXPLORATIVE AI FOR CONCEPTUAL DESIGN AND SPECIFICATION ENGINEERING OF A MULTI-FUNCTIONAL AUTONOMOUS ROBOTIC PLATFORM FOR SMART URBAN SERVICES
The design of autonomous robotic systems involves selecting and integrating components while ensuring feasibility across functional and environmental constraints. This study introduces an Explorative AI-driven methodology for generating and refining modular robotic platform configurations. The AI model analyzed millions of design configu-rations, identifying over 1400 feasible variants based on mobility constraints, energy consumption, subsystem com-patibility, operational scalability, and regulatory compliance. A multi-objective optimization process refined these variants, ensuring compatibility across subsystems while minimizing integration conflicts. From these, a final opti-mized robotic system configuration was selected, which was then documented in an extensive 100,000-word engineer-ing specification covering structural design, functional integration, and system-level justifications. This comprehen-sive output, covering every aspect of the design, ensures the system can be implemented with minimal design omissions or integration errors. The proposed methodology enhances early-stage robotic design by systematically generating, evaluating, and documenting configurations, reducing risks in later development stages.
DIGITAL MONITORING SYSTEMS IN THE FOOD INDUSTRY: A REVOLUTION IN QUALITY AND EFFICIENCY
The growing concerns about the increase in population necessitate modern technologies to increase the productivity in the food industry and support the new challenges of food safety and quality (FSQ) risks. The paper aims to discuss the application of digital monitoring systems (DMS) in the food industry, highlighting the integration of emergent technologies (e.g., Artificial Intelligence (AI), Internet of Things (IoT), blockchain, big data analytics etc.). These technologies enhance real-time monitoring, traceability, and control throughout the entire food supply chain, ensuring high standards of FSQ. Finally, there is presented the digital monitoring system development approach and generic architecture, considering the main characteristics and solutions present in the literature and in practice (based on the legal framework in Europe and stakeholders’ involvement).
UNLOCKING POTENTIAL: HOLISTIC AUTOMOTIVE RISK BREAKDOWN STRUCTURE MODEL IN CHALLENGING TIMES
The present study aims to establish a systematic conceptual framework based on Risk Breakdown Structure (RBS) to be used by the product development Team and Management for the dimension of risk sources identification in new holistic automotive product development, in challenging times. The study contributes a pragmatic direction for the business environment, whose risk sources and conceptualization were reviewed in a work group with remarkable experience and validated through an empirical analysis.
INFLUENCE OF CONSTRUCTIVE PARAMETERS OF FDM 3D PRINTING IN THE PIPE WITH HOLE FABRICATION
In this study, the authors focus on establishing constructive characteristics that can influence the additive manufacturing process of a pipe with hole or a simple pipe with high-speed polylactic acid material. In the paper, after an initial study on the main current aspects of additive manufacturing, the main components used to carry out the study are presented. One of the important elements, along with the dimensional one, was that of the emissions generated in the additive manufacturing process, including CO2 emissions. Next, the main constructive elements that affect the manufacturing process are detailed and determined in the logical order of the implications in the manufacturing process.
INTEGRATING SMART TECHNOLOGIES INTO MODULAR AND FLEXIBLE ARCHITECTURE
The built environment is undergoing transformation, as integrated smart technologies with modular and flexible architecture enhance sustainability, efficiency and adaptability. These include the Internet of Things (IoT), artificial intelligence (AI), and robotics, which improve modular constructions by prefabrication, scaling, and adaptable spatial configuration. AI-based design can enable real-time customization and accelerate assembly through automation, minimizing costs and errors. This study focuses on modularity, complexity and integration of smart systems, addressing issues of data privacy, interoperability, technology obsolescence, and examining the potential of resilient futures-ready architecture.
A METHOD TO EVALUATE THE LIFE CYCLE SUSTAINABILITY VALUE OF ALTERNATIVE SOLUTION DESIGNS
The paper focuses on developing an integrative methodology to evaluate environmental, economic, and social sustainability of alternative solution design options. Core approach is to extend the classic method of Quality Function Deployment (QFD) towards a holistic integrated model to overall evaluate the different aspects of all three pillars of sustainability (economy, ecology and social) across the product life cycle. The methods identify key aspects and allow users to consider and weigh different life cycle aspects in a overall scoring scheme.
A NOVEL APPROACH TO REAL-TIME TORQUE MEASUREMENT THROUGH IOT-INTEGRATED STRAIN GAUGES AND NEURAL NETWORK CALIBRATION
The paper emphasizes the conceptual design and theoretical evaluation of an Internet of Things (IoT)-enabled torque measurement system for vehicular drivetrains. The proposed system integrates cost-efficient components, including a Wemos D1 Mini ESP8266 microcontroller, BF350-3HA-E strain gauges, and an HX711 load cell amplifier, to enable real-time monitoring of rotational forces. Calibration is performed using a dynamometric wrench compliant with ISO 6789:2017 standards, covering a torque range of 5–50 Nm. The system is theoretically expected to achieve ±1.5% accuracy at a cost below 30 euros. The novelty lies in its ability to combine affordability, portability, and precision with IoT-enabled intelligent measuring and control capabilities. This work offers a scalable solution for cost-sensitive automotive applications, with potential for experimental validation and broader adoption.
WELDED STEEL BRIDGE INTEGRITY ENABLED BY SMART INFORMATION MANAGEMENT ACROSS THE ASSET LIFECYCLE
This paper presents a BIM-enabled framework for improving decision-making, quality control, and asset management applied to steel bridges. By integrating information management throughout the asset lifecycle, non-destructive testing, and predictive maintenance concepts, it addresses challenges like fatigue failure and material degradation considered linked to execution class. A key contribution is the “backward standard correlation” approach, that ensures integration of operational needs in design, aiming to optimize procurement and reduce lead times, while enhancing overall lifecycle cost efficiency. The proposed BIM-based approach enables real-time monitoring, stakeholder collaboration, and structured data exchange within a Common Data Environment. The proposed approach supports Industry 5.0 principles, by advancing digitalization, enhancing design and execution practices, while offering a solution for long-term performance monitoring.
EVALUATION OF THE MECHANICAL BEHAVIOR OF G-AENIAL RESTORATIVE COMPOSITES USING MULTI-CYCLING INDENTATION
During the mastication process, the restorative materials are exposed to dynamic loading as tooth cusps and hard foods cyclically indent these materials. In this work, the indentation technique is used to investigate the mechanical behavior of G-ænial under various multi-cycling nanoindentation conditions and to study the mechanical properties, such as elastic modulus and hardness. First, static indentation tests were performed to assess the effect of the holding time on the mechanical behavior of G-ænial. Then, a series of dynamic indentation tests were conducted in which the number of indentation cycles varied from 6 to 30. The experimental results indicated that both the static indentation hardness and elastic modulus decrease with increasing holding time from 0 s to 30 s. Moreover, the elastic modulus and indentation hardness of the G-ænial composite decreased with the increasing number of cycle loadings, indicating that the restorative composite becomes more susceptible to fatigue damage.
Adriana-Madalina TURCANU (CONSTANTINESCU)
INFLUENCE OF PHOTOPOLYMER RESIN MIXTURES ON PHYSICAL AND FRACTURE PROPERTIES
This study examines the fracture behavior of Single Edge Notched Bending (SENB) specimens produced using Digital Light Processing technology. The focus is on the effect of blending two UV resins (from pure White to pure Black) on fracture properties and specimen accuracy. The research also explores crack propagation mechanisms, along with the characteristics of SENB fracture surfaces. Findings indicate that the resin mixture significantly influences the investigated properties. Among the tested specimens, W75B25 mixture shows the highest mode I fracture toughness and fracture energy, while B100 exhibits the lowest. Additionally, W25B75 and W75B25 mixtures present the smallest dimensional errors, and B100 has the lowest mass. The specimens exhibit brittle behavior, with cracks initiating from the notch tip and no observed plastic deformation.
INFLUENCE OF LAYER THICKNESS ON COMPRESSIVE BEHAVIOR OF KAGOME STRUCTURES
This study focuses on the behavior of mechanical metamaterial structures under compressive loads and investigates the influence of production parameters on final properties of Kagome structures manufactured through stereolithography (SLA) using photopolymer resin. Tough 2000™ is a resin used for engineering applications developed by Formlabs, known for its high tensile strength, stiffness, and impact resistance and provides an ideal material for lightweight yet durable lattice designs. The study evaluates the influence of layer thickness on mechanical performance and the results revealed that increasing the number of layers reduces structural strength due to cumulative deformation effect and increases the ductility of the materials. The findings highlight the versatility of SLA-printed Kagome lattices for advanced engineering applications requiring lightweight, high-performance materials with tunable mechanical properties.
STUDY ON THE POSITIONING ACCURACY FOR A NEURAL NETWORK CONTROLLED ROBOTIC ARM END-EFFECTOR
This paper explores the potential of using a neural network to position a robotic arm's end effector. Traditional methods rely on direct and inverse kinematics, but this study draws inspiration from human hand-eye coordination—how people learn their hand’s workspace and reach for objects. In robotics, a similar approach could involve using a depth camera to detect and grasp objects directly. The neural network learns the relationship between joint angles and end-effector positions within the camera’s field of view, with applications in manipulation, object handling, and collaborative robotics in dynamic environments. Simulations on a 3-DOF robotic arm tested 10 architectures, revealing feasibility for direct kinematics but challenges in inverse kinematics requiring further research.
OPTIMIZATION OF MANUFACTURING PROCESSES, THE NEW CNC TECHNOLOGIES IMPLEMENTATION
The paper presents the stages of manufacturing a part in a CNC milling center, stages chosen specifically to present new machining technologies on CNC machine tools. In some of them, comparisons were made between different machining processes with positive but negative recommendations regarding the machining options, which we consider useful for application engineers. In other cases, comparative graphs were drawn with the time achieved through different processes, graphs regarding the amount of material removed. Experience and permanent upgrading of knowledge are essential in computer-aided programming, to operate and program the machines with numerical control. The actual machining of this part was done to certify and validate the theoretical and simulated arguments on different CAM (Computer Aided Manufacturing) software.
LEAN AND SUSTAINABLE MANUFACTURING IN AGGREGATE PRODUCTION: A CASE STUDY
This study analyzes aggregate production at Mill 1 by integrating value stream mapping with sustainability indicators to address capacity underutilization and resource inefficiency. The analysis identifies key challenges such as excessive energy consumption, high sludge generation, aging technology, and downtime. To mitigate the identified issues, the study proposes strategies such as predictive maintenance, optimized conveyor scheduling, screening automation, and improved resource management. These improvements are expected to significantly increase operational efficiency, reduce environmental impact, and improve worker safety, ultimately contributing to a more sustainable production of building materials. The resulting framework is replicable and applicable to other intensive resource industries.
STUDY ON THE MEASUREMENT ERROR ANALYSIS OF AN OMM MEASUREMENT SYSTEM USING A PROBING MODULE CAD-CAM SOFTWARE
The purpose of this work is to establish and validate an efficient dimensional inspection system by using the On-Machine Measurement (OMM) process with the aid of a measurement module of a CAD-CAM program. In recent years, CAD-CAM software’s has introduced modules that allow the measurement of parts executed directly on the machine tool. Through this system, the quality of the executed part can be controlled. To perform this study, an aluminum part was designed and machined by milling on a 3-axis CNC machine. The finished part was dimensionally measured on the milling machine using an OMM system and on a dedicated Coordinate Measuring Machine (CMM), thus being able to compare the accuracy and errors of using an OMM system. According to the measured values, there are no significant differences between the measurement methods of the two OMM, but larger deviations can be observed between the measured values obtained from OMM and CMM methods.
STUDY ON AI-GENERATED 3D PRINTED ABS PARTS: INFLUENCE OF INFILL TYPE AND PERCENTAGE USING FACTORIAL ANOVA, REGRESSION, AND MULTI-OBJECTIVE OPTIMIZATION
This study presents a comprehensive factorial analysis and ANOVA-based approach to optimizing 3D printing efficiency by investigating the impact of infill type and infill percentage on printing time and material consumption. The research integrates text-based and code-based CAD generation based on AI tools for designing the 3D printed part, followed by statistical evaluation using MATLAB. The results provide useful insights into balancing print speed and material utilization, enhancing additive manufacturing efficiency. The material used for the investigated printed parts is ABS.
DESIGN AND MANUFACTURE OF A PIPE-CLAMPING DEVICE FOR EXPERIMENTAL ANALYSIS OF LONG THIN-WALLED- TUBULAR PARTS
The aim of the paper is to carry out experimental verifications regarding the elasto-plastic deformation of round, thin-walled pipes. The paper has two goals. The first goal was to create a clamping device for long pipes. The second goal was to carry out specific experiments with this device, which would verify the calculation relation obtained in a previous theoretical research. The paper presents aspects related to the design and manufacture of the device. The experiments carried out are also presented, through which the elasto-plastic deformation that occurs when processing holes in long, thin-walled pipes was highlighted, and compared to the theoretical relation previously established. The conclusions presented confirm the achievement of the proposed goals, through 100% original contribution.
MULTI-CRITERIA ANALYSIS OF FDM ADDITIVE MANUFACTURING PROCESS FOR COMPONENTS WITH CYLINDRICAL GEOMETRY
This work was carried out as a continuation of previous studies related to the influence of positioning of gear-type or tubular parts. The authors considered expanding the investigation process by approaching in parallel the modified psychological experimental analysis, but also considering the economic, environmental and dimensional aspects and the surface quality for stepped cylindrical parts. To make the parts, a material was used that has as its basic structure poly lactic acid which is modified to be able to work at high printing speed. To establish the optimal constructive orientation that can influence the manufacturing process of the parts, the printing surface was considered. Based on the present study, it was observed that making the parts in a vertical position best satisfies the environmental and constructive criteria and was positioned in the same place at a short distance from the economic point of view from the horizontal printing position.
FLEXIBLE, SMART MANUFACTURING SYSTEMS AND INDUSTRIAL ENERGY MANAGEMENT SYSTEM IN AUTOMOTIVE FIELD
In one word, to improve productivity, sustainability, and efficiency, the automotive industry is putting more and more emphasis on smart manufacturing, flexible manufacturing, and industrial energy management systems. Two important areas of development to handle the potential and challenges in this industry are the identification of energy flexibility measures and the incorporation of modern technology. An industrial energy management system (IMES) designed to meet the specific needs of the automobile industry must have several essential elements to manage energy in production facilities.
DESIGN METHODOLOGY FOR A RADIUS IMPLANT USING CATIA V5 R19
This study explores the use of CATIA V5R19 in designing a customized wrist implant for orthopedic applications. By importing CT scan data, a patient-specific 3D model is created to ensure anatomical accuracy and biomechanical compatibility. Using CATIA’s Part Design, Generative Shape Design, and Assembly modules, the implant is optimized for stability, mobility, material selection, and weight distribution. Results demonstrate the software’s precision in facilitating implant design and mechanical evaluation. This research underscores the potential of CAD-driven implant development for personalized medical solutions. Future work will incorporate advanced biocompatible materials and additive manufacturing to enhance implant performance and clinical applicability.
MANUFACTURING IN INDUSTRY 4.0 TOWARD INDUSTRY 5.0
The paper examines the transition from Industry 4.0 to Industry 5.0, focusing on significant transformations in manufacturing. While Industry 4.0 emphasizes digital connectivity, automation, and data-driven smart personalization, Industry 5.0 reintroduces human collaboration and sustainable practices, aiming for adaptive cognitive manufacturing systems. This new paradigm leverages advanced technologies like AI, smart sensors, blockchain, and digital twins to enhance efficiency, innovation, and human-centered approaches. The article outlines the evolution of production paradigms, moving from mass production to mass personalization, driven by big data and smart systems. It also highlights the development of smart manufacturing systems, including the integration of smart tools, real-time monitoring, and data analysis frameworks, alongside steps to implement sustainable, customized, and flexible production processes.
ARTIFICIAL INTELLIGENCE ASSISTED DESIGN AND INNOVATION FOR INDUSTRY 5.0
This paper proposes a reconceptualization of artificial intelligence in design, aligned with the philosophical foundations of Industry 5.0—where innovation is guided by ethics, purpose, and human values. It introduces Unified Design Intelligence (UDI), a framework that integrates four AI roles -explorative, generative, cognitive, and discoverative - to support co-evolutionary design processes. Unlike the use of AI for predefined, task-bound operations, UDI enables AI to contribute to value-driven ideation, contradiction resolution, and context-aware innovation. The framework is validated through case studies in manufacturing, robotics, mobility, and product authentication. Results confirm UDI’s capacity to align technological capabilities with societal relevance and ethical foresight, showing that the real shift in Industry 5.0 lies not in what AI can build - but in why and for whom we choose to build.