The thickness variation during sheet deep drawing process has an impact on the quality of the final product and can lead to local material fractures. To minimize this phenomenon caused by varying degrees of stretching in different areas of the sheet, various methods can be employed. This research paper introduces a novel technique for metal sheet deep drawing, specifically designed for parts with complex geometric shapes that exhibit significant variations in deformation levels across different areas. The objective of this method is to enhance the quality of the deep drawing process by reducing thickness variations in the final part. In this proposed approach, the vertical movement of the punch is accomplished through two vertical rotational movements. This increases the flexibility of the deformation process, ensuring that the active tools elements occupy the most advantageous positions determined by the material flow in the die. As a result, the material's deformability is improved, allowing for a higher degree of deformation. Additionally, this new method offers a relatively simple design and kinematics solutions for the press and eliminates the need for lengthy assembly-disassembly times.

Rapid Prototyping is the rapid fabrication of a part, model, or physical assembly that was designed using any design software (Autodesk Inventor Professional in this case), which is a CAD (Computer-Aided Design) application that helps in the creation of a digital prototype. The creation of the part, model, or assembly is usually completed using the manufacture of additives or more commonly known as 3D printing. The paper presents a 3D design, 3D printing, and verifying the actual dimensions of the printed „washer”. The purpose of this paper is to verify that printing errors are controllable and can be reduced. The paper contains and explains all the mandatory steps required to do this experiment and the laboratory equipment that was used to do this.

Duralumin 2024-T351 is an alloy characterized by a good mechanical strength, relatively high hardness and corrosion resistance frequently used in the aeronautical, automotive, defense etc. industries. In this paper, the variation of axial forces and torques when drilling aluminum alloy 2024-T351 was investigated, analyzing the measured values for different cutting regimes. Experimental data on the forces and moments generated during the drilling process were collected using specialized equipment, and these data were preprocessed and analyzed using MatLab R218a. The experimental plan included 27 combinations of the parameters of the cutting regime (cutting depth, cutting speed, and feed), for which energetic cutting parameters were measured, the axial force and the torsion moment, respectively Based on these data, a neural network was trained, using the Bayesian regularization algorithm, in order to predict the optimal values of the cutting energy parameters. The neural model proved to be efficient, providing predictions with a relative error below 10%, indicating a good agreement between measured and simulated values. In conclusion, neural networks offer an accurate alternative to classical analytical models, being more suitable for materials with complex behavior, such as aluminum alloys.

Polymeric materials represent synthetic macromolecular products, from which objects of various shapes can be manufactured, through mechanical or thermal processing. These materials are used in various industries due to their versatility and ability to adapt to various applications. The paper presents an analysis of deviations from circularity in the drilling process of three types of polymeric materials: PA6 (polyamide), PEHD (high-density polyethylene) and POMC (polyacetal). The main purpose of this analysis is to evaluate and measure the deviations from circularity in the drilled plates using specific drills on the EMCO MILL 55 CNC machine and the precise determination of these deviations is realized with the help of the Sinowon 3D measuring machine. In the context of the processing of polymeric materials, both technical performance criteria and their associated factors in drilling operations are examined. In the study, two types of helical drills were used, with two rectilinear cutting edges, having different diameters, Ø8 mm and Ø10 mm, made of high-speed steel.

Recognizing the crucial role that transport and lifting installations play in various sectors, including industry, construction, and extraction, as well as in mechanizing loading and unloading operations, and the movement of equipment or materials, special attention must be oriented to the diversification and the production of these installations by using the most advanced technologies. The paper presents some operating principles and characteristics of a lifting and transport Spider Crane installation equipment. This installation is considered a more economical and efficient alternative to traditional cranes for works where lifting requirements are below certain limits and significant height. Thus, an analysis of the hydraulic lifting system was carried out, based on the calculation of hydraulic fluid flows for the drive pumps. Also, was evaluated the specific speeds and forces of the hydraulic cylinders, a mechanical analysis of the clamping system with hook, as well as a finite element analysis of some mechanical and hydraulic components.

This paper presents a variant for determining the enwrapping condition, in the case of rack gear type tools. This variant was called the “virtual pole method”. The position of the virtual pole Pv is defined by the movement angle of the blank together with the centrode associated with the generated profile. The virtual pole method allows translating in the centrodes’ absolute movements, a point on the generated profile, on to the rack tool profile, thus determining the geometric locus representing the generating tool profile. The new method is easier to apply, while remaining scientifically rigorous. By applying the proposed algorithm, it is no longer necessary to write explicitly the relative movements between the tool and the piece, which simplifies the calculation process and eliminates some of the possibilities for errors.

In this study is presented a systematic analysis of already published works on the field on sheet metal rubber-pad forming. This analysis consists on a comparative approach about different methods used in metal forming processes. During last year’s different technologies were developed and studied. New approaches and research directions were identified. Using new materials for punches and dies the metal forming processes become more and more competitive from cost point of view and also they are in trend with aerospace and automotive industries which use the knowledge to improve their products and their cost reduction/saving strategies. This overview of the actual status of the researches developed in sheet metal rubber-pad forming provide a basis for future work and futures development projects.

The quality of the refill friction stir spot welding (RFSSW) process is heavily dependent on the selected welding parameters that influence the resultant joint characteristics. Thermomechanical phenomena integral to the process were investigated using finite element (FE) analysis on two dissimilar materials. This FE analysis was subsequently validated through controlled experiments to ensure reliability. An artificial neural network (ANN) was employed to create a neural model based on an experimental setup involving 120 different sets of welding parameters. The parameters adjusted in the experimental plan included pin penetration depth, rotational speed, retention time, and positioning relative to material hardness. To assess the neural model’s accuracy, outputs such as maximum temperature and normal stress at the end of the welding process were analyzed and validated by six data sets selected for their uniform distribution across the training domain.

In this paper two constructive solutions for central conical worm from composition of helical compressor are analyzed. First is a worm with cycloid frontal profile and the second one is a worm with circle arc frontal profile. The conjugated worm for the conical rotor is determined based on the fundamental theorems of surface enwrapping. Afterward, the area between the flanks of lobes for drive and driving worms are calculated in sections perpendicular to the axis of driving worm. For equals dimensions of worms it is estimated the volume included between the drive and driving worms, as determining factor defining the compressor flow.

The paper presents an algorithm for profiling the hob tool designed to generate by plastic deformation the worm shafts from the composition of worm-wheel gear type, used in the seat adjustment mechanisms of some Audi and Mercedes cars. The active surface of the hob tool is a cylindrical helical surface of constant pitch. Two such tandem tools are used for deformation, the semi-finished product being positioned between them. During generation, the tools rotate around their own axes, which, combined with their helical surface, causes a helical movement of the blank. The active surfaces of the tools are mutually winding on the helical flanks of the generated worm. In the paper, two applications were developed for the generation of worms whose dimensions were determined by 3D scanning.

This paper presents the profiling of the hob mill designed to generate the active surface of the cam of a cycloidal reducer. The algorithm allows determining the active surface of the generating rack gear, which is reciprocally enveloping with the active surface of the cycloidal disk. The novelty of the algorithm, based on the determination of the intermediate surface, consists in the fact that an innovative method of determining this surface is used, called the "virtual pole" method. The method allows determining the enwrapping curve of an ordered curl of surfaces, generated in the rolling movement of two conjugated centrodes. Using the "virtual pole" method, the calculation time for tool profiling is significantly reduced and the disadvantage of the resulting error, small enough to be neglected from a technical point of view, is fully compensated by this reduction in calculation time.

With the continuous and steady development of rapid prototyping technologies and the use of personalized 3D printed parts obtained through these technologies, their optimization was the next step in order to maintain or even reduce the amount of material needed to print the various elements/parts, while maintaining, if not increasing their strength, as well as optimizing the time required to print the same or a larger number of elements/parts. Based on the results obtained in the previous paper, [1], we proceeded to the experimental validation. In this paper, it is proposed to 3D print the samples previously researched, respectively, the model with a predefined infill structure and the sample with an infill structure optimized to the expected stresses to occur during a normal exploitation and having an „ogive” type rib. Based on the stresses that are expected to occur during a normal operation, the laboratory experiments will be videotaped and the photo images extracted from these video materials obtained after the tests, will be use to check the possible deformations that appear on the samples. The deformations obtained by subjecting them to compression are then analyzed using the GOM Inspect and GOM Correlate programs. The favorable results will contribute to the development of an algorithm that will allow the generation of optimized infill patterns for different types of stresses expected to appear and possibly applying the custom infill structure concept to other rapid prototyping technologies. The rapid prototyping technology used in this paper is FFF/FDM (Fused Filament Fabrication/Fused Deposition Modeling), with an Ultimaker 3 Extended 3D printer.

The issue of generating surfaces which are ordered curl of surfaces, using profiled tools, is a current concern of the international research teams. The performance of the generating by machining depends by the cutting tool's geometry, and the 3D modelling allows a simple and rigorous analysis of the actual geometry of tool's cutting edges. Initially, the issue of surface generating by enwrapping has a graphical approach and subsequently an analytical one. This analytical way to study the generating by enwrapping processes is yet frequently used by researchers. A fundamental contribution had F. Litvin which approaches the modelling of the teethed wheel, in analytical form, as base of the general issue of design for this type of parts [1]. Obviously, the analytical approach of the surface generation is very important in this domain, but this can and has to be completed or, where the methodology allows, replaced with alternative methods. Sometimes, these methods are easy to use and induce minimum errors from technical point of view. The continuous development of the graphical design environment allows returning to the graphical or grapho-analytical approach for the surface's enwrapping problems, using capabilities offered by AutoCAD, CATIA, Solid Edge or other graphical design programs. At "Dun.area de Jos" University of Galati, in the department of Manufacturing Engineering, a research team, of which the authors of this chapter are also part, developed applications in the graphical design environment, solving problems of the tool's profiling for the generation of: ordered curl of surfaces associated with a couple of rolling centrodes and tools bounded by revolution surfaces, generating helical cylindrical surfaces with constant pitch. All these approaches give solutions based on enwrapping fundamental theorem, like the Olivier or Gohman theorems, for enwrapping problems. In the frame of the same research team, an alternative method was developed based on the simplification of the Willis theorem, method published as method of "virtual pole". During the elaboration of previous works, it was observed that it is possible the elaboration of some scripts which allows automatizing the process of tool's profiling, in the frame of previously mentioned graphical design environments. In the present chapter, the method of "virtual pole" is presented and a program for profiling the generating tool was developed for the first time. The programs were written in Visual Basic for Applications (VBA), which allows profiling of tools like: rack-gear tool, gear shaped cutting tool or rotary cutter.

In industrial practice, is sometimes needed to manufacture specific parts without blueprints. This part of engineering process is known as reverse engineering. Usually, this assumes that an existing piece is measured or scanned and based on this result is made a new part. If the part can be machined with universal cutting tools the manufacturing process don’t rise problems, but in case of parts which needs specific tools, these must be designed to be suitable for machining the piece. In this paper, a tool profiling algorithm is proposed, which is based on the capacity to measure and represent some surfaces in a methodical cloud of points form. The proposed profiling algorithm is based on the “virtual pole” method. This method is used together with the intermediate surface theorem for profiling tools characterized by a helical primary peripheral surface. This article will represent a continuation of a research which was been published in 2021, in Bulletin of Polytechnic Institute from Jassy. In that published article, the profiling of the hob mill tool was presented in a theoretical way and the ”virtual pole” theorem was applied for an any type of profiles. The proposed algorithm allowed the determination of the tool’s profile reciprocally enveloping with a piece’s profile known in discrete form. Now, in this paper, the discrete form profile will represent exactly a cycloidal disk from a cycloidal reducer whose coordinates were determined using specific reverse engineering processes. Considering that the determination of the relative movements between the tool and the part, as well as the determination of the enveloping condition are relatively complicated and can be a source of errors, the purpose of this work is to highlight the advantages of the ”virtual pole” method compared to the other specific methods of tool profiling that generate by enwrapping. At the same time, it is investigated if the ”virtual pole” method can provide a support for the identification of the intermediate surface, with the help of graphic design environments, for profiling, in this case, the worm tools, since the ”virtual pole” method cannot be applied as such in the case of disk-type tools, worm tools and cylindrical-frontal tools, due to the fact that the theorem is intended for the study of planar gearing. The advantages of using the ”virtual pole” method are obvious compared to the classical tool profiling methods. The results demonstrated the accuracy of the method, by the fact that, using the ”virtual pole” method, the calculation time for profiling the hob mill tool for generating a profile known in discrete form, namely the profile of the cycloidal disk, is significantly reduced.

The blast furnace sludge is a waste product of the steel industry which is produced in considerable quantities and there is permanently concern to use them, to limited environmental pollution. Our work presents the chemical and mineralogical characterization of the blast furnace slurries for the preparation of ultrafine ferrous slurries resulting from the process of obtaining cast iron in the blast furnace. The main chemical elements, from XRF analysis are as iron, calcium, silicon, magnesium, combined in chemical compounds such as silicates, silicon oxide, hematite or magnetite. The sintering laboratory tests using sludge showed better results for the proportion of minerals that include iron and its oxides in the ferrous agglomerate, compared to the furnace sludge, from XRD measurements and SEM-EDX analysis. It is a possible to use them on the existing industrial flows, introduction into the agglomeration batch, in order to obtain the ferrous agglomerate needed for the technological process in the furnaces. In this way, there is a solution, to reduce significantly environmental pollution by avoiding their handling, transport, and storage in open dumps and preventing contact with human settlements.

Refill friction stir spot welding (RFSSW) technology is a solid-state joint that can replace conventional welding or riveting processes in aerospace applications. The quality of the new welding process is directly influenced by the welding parameters selected. A finite element analysis was performed to understand the complexity of the thermomechanical phenomena during this welding process, validated by controlled experiments. An optimization model using neural networks was developed based on 98 parameter sets resulting from changing 3 welding parameters, namely pin penetration depth, pin rotation speed, and retention time. Ten parameter sets were used to verify the learning results of the optimization model. The 10 results were drawn to correspond to a uniform distribution over the training domain, with the aim of avoiding areas that might have contained distortions. The maximum temperature and normal stress reached at the end of the welding process were considered output data.

In most situations, for the proper design of a gerotor pump, numerous parameters must be taken into account: the pump geometry, the properties of the materials from which the pumps are made (Young’s modulus, Poisson’s coefficient, friction coefficients, etc.), the hydraulic characteristics of the circulated fluids (fluid density, kinematic viscosity, etc.), the working performance of the pump (speed ranges, pressure, flow rate, etc.), with greater or lesser influence on volumetric efficiency, work capacity, or energy consumption. The paper presents a study regarding the inspection of the reciprocally enwrapping surfaces of the gerotor pumps using a three-dimensional measurement technique specific to reverse engineering, which involves 3D scanning of the pump components in gearing movement. The components were measured by means of a specific software (GOM Inspect) and compared, by overlap, with the CAD models made with the help of CATIA software (CATIA V5R21). At the same time, an analytical calculation algorithm was developed for the complementarity of virtual representations. Finally, the advantages of the reverse engineering technique compared to the developed theoretical algorithm and traditional CAD design are presented.

The paper proposes a method for identifying the front profile of a worm-type active element, consisting of a three-screw compressor. The purpose of this identification is to study the frontal enwrapping between the profiles of the driver and the driven element, in order to produce a possible replacement element. As is it well known, the two profiles are mutually enwrapping profiles, which means that the problem can be treated as a plane enwrapping problem. The identification of the profiles was performed by specific reverse engineering methods, the parts being scanned on an ATHOS 500 scanning system. Subsequently, the analytical shape of the driven screw was identified and, applying the “virtual pole” method, the corresponding shape of the driver screw profile was deduced. The obtained profile was compared with the real profile, obtained by 3D scanning. The obtained results demonstrated not only the good match between the theoretical and the real profile but also the simplicity and robustness of the method applied for the study of the enwrapping, namely the “virtual pole” method.

Recently, 3D measurement systems have developed more and more in various fields. With the help of 3D measuring systems, the measurement time in design, manufacture, assembly and production is substantially reduced. In this paper, it is proposed to redesign two pieces of a helical pump (driver and driven screws) based on numerical models obtained by scanning. These models are obtained based on the processing of point clouds resulting from the 3D scanning of the respective pieces. After completing the actual scanning process, the numerical models were measured using specific software to determine the dimensional characteristics and their modeling was performed in a computer-aided design program. Subsequently, the inspection was performed by overlapping the scanned model and the CAD model of each piece, in order to be able to compare the analytical models with the real pieces. This comparison allows to appreciate the degree to which the analytical model obtained by redesign corresponds to the real piece. In this way, the ability of future pieces obtained based on the analytical model to be able to accomplish the desired functional role can be appreciated.

There are known methods of corrective profiling of tools, which can predict the quality of parts generating obtained with cutting tools that process by enwrapping. The purpose of this profiling is to avoid errors caused by improper profiles of generating tools, using the so-called method of "reverse generation", which is based on the reproduction of the relative movement between the tool and the part, but in which the tool profile is known, and the goal is determining the part’s profile. The method presented in this paper uses the "virtual pole" method to profile the tools generating by enwrapping, by the rolling method and avoids the need to explicitly write the enveloping condition. This paper demonstrates the possibility of applying this method to the profiling of gear-shaped tools and presents the application of the proposed algorithm for a tool whose profile was determined directly by measurement. The numerical application developed demonstrates the ability of the method to simply solve the problems related to the corrective profiling of the tools that generate by rolling.