Recently, non-contact sensor technologies are more and more often used for quality inspection tasks as well as for process monitoring in manufacturing. As a matter of fact, recent advancements in laser scanners and machine vision systems provide the potential to greatly improve the performance of Statistical Process Control (SPC) approaches. In this paper, a PC- based machine vision system, which provides rapid measurement of freeform geometric features, is presented. The measuring system is based on appropriate hardware and software modules. The hardware module consists of a laser scanning device and setup fixtures that can provide proper location and orientation for the part to be measured. The software module generates optimal scan plans so that the scanning operation can be performed accordingly. Furthermore, measurements for each geometric feature are automatically stored by the software module in order to perform on-line statistical analysis. The system described in this paper has been designed for on-line data acquisition, quality inspection, and statistical monitoring of actual manufacturing processes. To these aims, a user-friendly, menu-driven graphical interface has been implemented in order to give the operator an effective overview of the process state (either in-control or out-of-control). A real case study, related to the production of stamped metal panels in the automotive industry, is described.

Bending can be considered one of easier sheet metal forming processes. In fact, it represents one of the basic variants of applied deformations to metal blanks. However, the numerous research contributions dedicated to sheet metal bending that have been published over the past decade and the constant stream of announcements by R&D departments of machine constructors are strong indications that not all research challenges related to sheet metal bending have been done. This paper reports the developed activity carried out to design a bending testing rig characterized by: a working horizontal axis, a maximum bending length equal to 200 mm, a maximum applicable force equal to 80 kN. A partitioned blankholder has also been designed to allow bending operations on tailored blanks. Moreover, a Graphical User Interface hollows to set up the process parameters and the acquisition of testing data (Temperature and/or Force as function of the process time or punch stroke). CAE tools application had a strategic role to develop the best layout and to find the optimum solutions for the process variables tuning. CAE techniques have allowed to investigate and verify different layout solutions both for the bending process and the structural components of the tooling.

In order to perform a successful sheet metal forming operation and to avoid shape deviations and tearing and wrinkling defects, process and material variables, such as tools geometry, blankholder force, friction, blank shape, sheet thickness and material properties, should be optimized. One of the main parameters which must be defined at the beginning of any sheet metal forming process design is the initial blank shape and its main dimensions [1]. In this paper, the authors’ attention is focused on a non-conventional sheet HDD process for which optimal blank shape and dimensions are not fully explored yet [2]. It will be demonstrated that, when the traditional One Step finite element method calculation, realised through the implicit code, is applied to HDD, the process shows various limits. In fact, while the One Step analysis is able to predict the optimal initial blank for the traditional Deep Drawing (DD) process, the same blank could not be the optimal one in a HDD process. The goal of this paper is to develop a methodology by which, with the aid of optimization algorithms, it will be possible for the user to define the best shape and dimensions for the initial blank in HDD processes, even when starting from the blank obtained by a One Step analysis.

Blank shape is one of the most important parameters of sheet metal stamping. In fact it can directly affect the forming quality of parts and it has to be taken in account in sheet hydroforming design. Reasonable blank shape not only can reduce materials and production cost but, also, it can improve the strain distribution of the material and product quality in the hydroforming process. However, it is not easy to find an optimal blank shape because of complexity of deformation behavior and presence of many process parameters like die radius, punch radius, punch speed, blank holder force and friction. In fact, they affect the result of the process i.e. tearing, wrinkling, springback and surface conditions such as earing. Even a slight variation in one of these parameters can result in defects. This paper reports numerical and experimental correlation for axis symmetrical hydroformed component using initial blank with different shape and size. Experimental tests have been carried out through the hydroforming cell tooling, designed by the authors thanks to a research project, characterized by a variable upper blankholder load of eight different hydraulic actuators. Two different initial blank shapes, square and circular, of same material and thickness have been used.

Warm bulging test is a particular kind of sheet hydroforming. The presence of a warm fluid requires a proper tooling design in order to achieve the benefits related to these particular forming conditions, minimizing blank ruptures and wrinkles presence. The fluid is injected in a properly designed chamber and it produces a sheet bulging deformation. Also the tooling and the sheet are warmed in order to maintain a constant process temperature. In this working conditions, it is necessary to accurately design the tooling layout taking into account: interaction forces, fluid volume, vision system in order to record the deformation conditions and safety systems in order to prevent damage to the workers caused by the warm fluid possible leakage (approximately 200° ÷ 300° C). CAE techniques have a relevant role in order to define proper process parameters such as: sheet thickness, bulging height, fluid pressure. An explicit solver has been used to calculate the forces distribution, developed during the warm sheet bulging, and the needed fluid volume. The obtained values have been used as input data in the structural tooling validation. The authors have designed a warm bulging test layout. The sheet deformation, etched with a grid, is detected through CCD cameras. Diffuse lights, a thermometer and a laser beam adopted to detect the dome height complete the tooling control system.

Most of the aeronautic skin parts are made through stretch forming of aluminium or titanium sheet metals over rigid fixed dies. In the aerospace industry, the stretch forming of aluminium or titanium sheets is widely used to produce aircraft skin, such as blended wing body sections, fuselage sections and nacelle skins. As the demand for more efficient and economical commercial transport increases, the requirements for reduced weight and improved performance become greater. In this work explicit FEM simulations have been used to analyze the forming process of an aeronautical engine fairing in order to numerically compare: tangential stretch forming, extensively used in the aerospace industry and single action drawing processes effects on the studied component. Titanium alloys have their advantages and disadvantages, and two important tasks are the understanding of the behaviour of the alloys and the matching among particular alloys and processes in order to maximize structural and operational efficiency. Equally important it is the ability to develop a fabrication practice that does not severely degrade material properties and that can be implemented at reasonable cost.

Rubber pad forming (RPF) is a novel method for sheet metal forming that has been increasingly used for: automotive, energy, electronic and aeronautic applications. Compared with the conventional forming processes, this method only requires one rigid die, according to the shape of the part, and the other tool is replaced by a rubber pad. This method can greatly improve the formability of the blank because the contact surface between the rigid die and the rubber pad is flexible. By this way the rubber pad forming enables the production of sheet metal parts with complex contours and bends. Furthermore, the rubber pad forming process is characterized by a low cost of the die because only one rigid die is required. The conventional way to develop rubber pad forming processes of metallic components requires a burdensome trial-and-error process for setting-up the technology, whose success chiefly depends on operator’s skill and experience. In the aeronautical field, where the parts are produced in small series, a too lengthy and costly development phase cannot be accepted. Moreover, the small number of components does not justify large investments in tooling. For these reasons, it is necessary that, during the conceptual design, possible technological troubles are preliminarily faced by means of numerical simulation. In this study, the rubber forming process of an aluminum alloy aeronautic component has been explored with numerical simulations and the significant parameters associated with this process have been investigated. Several effects, depending on: stamping strategy, component geometry and rubber pad characterization have been taken into account. The process analysis has been carried out thanks to an extensive use of a commercially finite element (FE) package useful for an appropriate set-up of the process model. These investigations have shown the effectiveness of simulations in process design and highlighted the critical parameters which require necessary adjustments before physical tests.

In the typical scenario of a helicopter crash, impact with the ground is preceded by a substantially vertical drop, with the result that a seated occupant of a helicopter experiences high spinal loads and pelvic deceleration during such crash due to the sudden arresting of vertical downward motion. It has long been recognized that spinal injuries to occupants of helicopters in such crash scenario can be minimized by seat arrangements which limit the deceleration to which the seated occupant is subjected, relative to the helicopter, to a predetermined maximum, by allowing downward movement of the seated occupant relative to the helicopter, at the time of impact with the ground, under a restraining force which, over a limited range of such movement, is limited to a predetermined maximum. In practice, significant benefits, in the way of reduced injuries and reduced seriousness of injuries, can be afforded in this way in such crash situations even where the extent of such controlled vertical movement permitted by the crashworthy seat arrangement is quite limited. Important increase of accident safety is reached with the installation of crashworthy shock absorbers on the main landing gear, but this solution is mostly feasible on military helicopters with long fixed landing gear. Seats can then give high contribution to survivability. Commonly, an energy absorber is a constant load device, if one excludes an initial elastic part of the load-stroke curve. On helicopter seats, this behavior is obtained by plastic deformation of a metal component or scraping of material. In the present work the authors have studied three absorption systems, which differ in relation to their shape, their working conditions and their constructive materials. All the combinations have been analyzed for applications in VIP helicopter seats.

Structural Optimization techniques are a well-known approach in order to improve Product Performances. Optimization procedures, many times, do not include manufacturing constraints arising from the Corporate technologies. This aspect becomes a disadvantage in the Design revue phase when the final Product release is a trade-off between the Optimization results and the Manufacturing constraints. This paper describes a specific new approach which considers product/process guidelines an input/output data in the optimization phase. The study case is represented by a high performances aeronautic seat structure having as mission profiles the SAE-AS Standards, in order to demonstrate occupant protection when a seat/occupant/restraint system is subjected to statically applied ultimate loads and to dynamic impact test conditions. The authors’ aim, in accordance to standards requirements, is to achieve a final design based on an optimized structural solution for the chosen process technologies taking into account the low volume production, typical attitude of the aeronautical industry. The presented study case offers the proper reference in order to extend this methodology to more complex structural applications.

The metal stamping is a forming process by plastic deformation of a metal surface carried by a punch in a die. During the process different deformation modes are possible. Thus, formability, the proneness of the material to be subjected to this kind of operation, it is very important for the process feasibility. If the blank is restrained between the die and the blank-holder, the metal stamping is said by stretching. In this case, the deformation status is of pure stretching. The Erichsen test is usually adopted to verify the material formability in this deformation conditions. In this test, the blank deformation is obtained thanks to a spherical punch. The friction in the contact of the sheet metal and the punch has influence in the deformations distribution. An alternative testing procedure for stretching conditions it is represented by the conventional bulging test. In this case, the deformation action is made by a pressurized fluid avoiding the effect of friction during the material deformation. This test condition better represents the deformation conditions when an unconventional process like direct hydroforming is adopted. In the present work authors have developed appropriate numerical models for the Erichsen test and, using the same tooling, except for the punch, a new bulging test has been developed. For the two different testing conditions the deformation status has been evaluated. The obtained results from the numerical analysis have confirmed a better formability in the case of the non conventional bulging test, with a more uniform distribution of the plastic deformation and of the thickness percentage reduction of the formed blank.

Nowadays the main target in the automotive field is the realization of lightweight and safe components. In this way it is possible to reduce costs and improve fuel consumption and, at the same time, enhance passenger safety. The use of tailored blanks has increased considerably in the automotive industry. Tailored blanks are a combination of different thicknesses or different materials, obtained by welding together two or more blanks, used in particular in car body panels. A new requirement in the automotive sector is the application of aluminum tailored blanks. The main target of this paper is the development of accurate numerical models for bending tailored blanks made from thin aluminum sheets, joined by laser welding, without filler metal. The FE bending simulations have been carried out using an explicit solver. The accuracy of the numerical models has been estimated and improved through a comparison with the results from an experimental study. The experimental tests have been performed using bending testing equipment, designed and developed by the authors. Three different bending radii have been tested. Tailored blanks, used as specimens, have been made by laser welding of thin A16061 sheets. The considered outputs, used for the numerical-experimental comparison, are the punch force and the bending angle. The experimental results have been compared with the numerical ones in order to verify the accuracy of the FE model related to thickness and radius variations

The aim of this work is to analyze the influence of cutting conditions on surface roughness with slot end milling on AL7075-T6. The considered parameters are: cutting speed, feed, depth of cutting and mill radial engage. Response surface models based on experimental data obtained with physical tests have been developed, the authors have performed a consistent set of experimental tests based on design points selected within the four-dimensional design space. Each test has been repeated 3 times to ensure the stability of the collected statistical data. These welldistributed results has been subsequently used to create RS models through approximation techniques based on polynomial and neural network methods and to verify their reliability in terms of correct responses behaviour. The obtained results show that the most significant factors affecting the surface roughness are feed and speed.

Springback is a really troublesome effect in sheet metal forming processes. In fact changes in geometry after springback are a big and costly problem in the automotive industry. In this paper the authors want to analyse the springback phenomenon experimentally in sheet metal hydroforming. Compared with conventional deep drawing, sheet hydroforming technology has many remarkable advantages, such as a higher drawing ratio, better surface quality, less springback, better dimensional freezing and capability to manufacture complicated shapes. The springback phenomenon has been extensively analysed in deep drawing processes but there are not many works in the literature about springback in sheet metal hydroforming. In order to study it, the authors have performed an accurate measuring phase on the chosen test cases through a coordinate measuring machine and the obtained measurements have been utilised for the determination of springback parameters, taking into account the method proposed by Makinouchi et al. The authors have focused their attention on the possibility of adopting a modified Makinouchi et al. approach in order to measure the springback of the large size considered test cases. Through the implemented methodology it has been possible to calculate the values of the springback parameters. The obtained results correspond to the observed experimental deformations. Analysing the springback parameter values of the different combinations investigated experimentally, the authors have also studied the pre-bulging influence on the springback amount.

The use of lightweight alloy offers significant potential to improve product performances. However, the application of formed lightweight alloy components in critical structures is restricted due to this material’s low formability at room temperature and lack of knowledge for processing lightweight alloys at elevated temperature. Warm forming is becoming of great interest in order to increase the formability of these materials and many conventional processes are adapted including the temperature as a new parameter. In addition to this option, warm hydroforming technology for the lightweight materials is currently emerging to achieve reduced number of manufacturing steps and part consolidation. The warm hydroforming process makes use of the improved formability at elevated temperature and it also utilizes the fluid to transport the forming action as well as heat. In the present work, the authors have studied the warm hydroforming process using two different numerical approaches in order to simulate it. The first software is traditionally used in metal stamping simulations (also warm and hot) unlike the second. The analyzed material is an Al 6061 alloy 2,03 mm thick. Process responses such as: bulge height, thickness reduction and strain distribution have been evaluated different temperature levels (room temperature, equal to 23°C, 100°C and 200 °C). The obtained results have been used to study the accuracy of the second software in sheet warm hydroforming simulation. The authors have also defined the more reliable numerical environment in order to develop material damage models in warm forming conditions.

In this work, a novel technological solution for the traceability of hides throughout the leather manufacturing process is addressed. The proposed solution relies on marking the raw hide with a permanent sub-surface tattoo, made with specific substances used as identification markers. In practical applications, the markers can be embedded so as to form a pre-established pattern, thus creating a unique identification code. To experimentally demonstrate the feasibility of the proposed solution, in this work, different types of markers were injected in a raw hide (i.e., prior to its tanning). After the tanning process, the persistence of the markers and of their pattern was verified by comparatively inspecting the hide with two different sensing technologies: microwave reflectometry and X-ray imaging. The obtained results demonstrated that the proposed traceability system is a promising solution to circumvent the age-old problem related to counterfeiting and fraudulent substitutions of raw materials in the leather manufacturing industry.

In the production of aerospace engine components, metal cutting processes are characterized by a strong demand for increased productivity that does not compromise the high quality of the product. The antithesis stands in the fact that it is necessary to maximize the feed rate and cutting velocity in order to reduce the processing time without compromising the quality of the worked component. In aerospace machining applications on hard-cut materials like: nickel based alloys, titanium alloys, etc, it is fundamental to keep under control the local cutting zone phenomena in order to assure the final product quality. The machining process design development can be summarized by the following steps: definition and verification of the Part Program (PP) through dedicated CAD–CAM software applications, post processing of the produced PP, CNC machine simulation and physical tryout. A further development of this procedure foresees the application of the kinematic optimization to improve the cutting process with a significant time reduction through the optimization of material removal along tool path. In this study a new multidisciplinary procedure is proposed. The aim of the authors is to modify the operation parameters set in the already kinematically optimized PP according to the constraints arising from the physical nature of the cutting process obtained by FEA. A milling operation that include the use of rough and finish tools related to an aeronautical engine component made by Inconel 718 has been chosen to test the developed methodology. The aims of the procedure is to minimize the execution time of the cutting process in compliance to physical micro-scale constraints (maximum admissible cutting edge temperature and maximum admissible Cutting Forces).This foresees the integration of the CAM softwares: Vericut for tool-path verification and Optipath for kinematic optimization of the given PP in the iSIGHT model. The procedure automatically extracts the values of feed and speed in all the blocks of the PP, which have been kinematically optimized, to verify if they respect upper limits (previously set) of: analyzed responses. In the PP blocks where the physical constraints are violated, a Pointer algorithm it has been used to automatically identify the optimal set of the process parameters within the defined design space of the RSM in order to respect the required physical constraints. The new set of process parameters has been updated into the blocks of the analyzed PP.

Fracturing by ductile damage occurs quite naturally in metal forming process due to the development of microcracks associated with large straining or due to plastic instabilities associated with material behavior and boundary conditions. Metal forming processes generally introduce a certain amount of damage in the material being formed. Predictions of the damage formation and growth in a series of forming steps may assist in optimizing the individual operations and their order. This is particularly true for operations such as cutting and blanking, which rely on the nucleation of damage and cracks in order to separate material. In this work numerical simulation of the blanking process, using Deform 2D, taking in account the damage, has been performed. In order to evaluate the accuracy of the numerical solution, experimental test have been performed. Furthermore a numerical experimental correlation has been carried out

Different parameters are used to evaluate the machined surface quality; roughness, residual stress and white layer are the most common factors that affect the surface integrity. Residual stress, in addition, are one of the main factors that influence the component fatigue life. Superficial residual stresses depend on different factors, such as cutting parameters and tool geometry. This article describes the development of an automated optimization procedure that allows the matching of a residual stress Target Profile by varying process parameters and tool geometry for a typical aeronautic superalloy, such as Waspaloy, for which a reliable numerical model has been developed for comparison to experimental data. The objective of this procedure is to maximize the Material Removal Rate under physical constraints represented by appropriate limits assigned to: Cutting Force, Thrust Force, Tool Rake Temperature and residual stress Target Profile. The developed optimization procedure has shown its effectiveness to match a given residual stress profile in accordance to process responses numerically evaluated.

Aero Engines main components made by nickel super alloys are mainly obtained by machining of large forged parts. The work piece machining process generates distortions and in some cases they may be relevant. In this contest, in many cases the removed volume in the machining operations represents a large percentage of the forged component in order to obtain the thin-walled wanted geometry. Due to this reason, the residual bulk stresses induced by the process history can lead to significant 3D geometric distortions in the machined component with unacceptable dimensions and shapes of the obtained product for comparison with the wanted geometry. Moreover, it is a matter of fact how, the final component distortions depend by the cutting strategy adopted in the machining process. The experimental study of such cutting strategies on real components are particularly time consuming and costly and for this reason the chance to study the problem using reliable numerical models it is particularly welcome. In the present work authors report the numerical model development to simulate the forging and machining processes needed for the production of an aircraft engine component and the comparison of the obtained results with the ones physically measured from a production batch.

The HDD process performance and the quality of the formed parts can be influenced by many process variables, such as: fluid pressure, blankholder force, pre-bulging pressure, friction and punch speed [1]. Many studies report how pre-bulging characterization may be done in accordance with the fluid pressure variation [2] or with the maximum bulge height [3][4] value. In this paper, the authors use the maximum bulge height to characterize pre-bulging levels influence on the process feasibility. The effects of three different pre-bulging levels as well as the traditional geometric and process parameters on a specific component characterized by an inverse drawn shape have been analyzed. In the experimental phase, for each considered process condition the Thickness Reduction (TR) has been detected on the formed component in sixteen different points of interest, to verify numerical and experimental correlation. The good accuracy shown by the numerical model allowed to develop an appropriate numerical campaign to obtain an ANOVA analysis to evaluate the pre-bulging heights influence on TR distribution. The obtained results have shown that the pre-bulging height influences the TR distribution significantly but in a less way than punch radius and blankholder forces profile.

Ecological awareness and economic analysis force industry to decrease the weight of transportation vehicles and to achieve a higher product quality with a reduction of production costs. Lightweight constructions made out of Tailored Blanks (TBs) and advanced manufacturing technologies, like sheet metal Hydromechanical Deep Drawing (HDD), help to reach these goals. From this point of view, HDD techniques have been largely accepted by the industry for the production of components characterized by: complex shapes, good surface quality and small residual stress. In this work, starting from previous studies of the same authors about hydroformed components with a redrawing area, an original approach based on Thickness Percentage Reduction (TPR) distribution has been implemented to design a particular TBs for HDD applications. Numerical and experimental results about the studied test case have been allowed the verification of their correlation as well as the necessary reliability of the implemented process simulation methodology.

Sheet metal hydroforming has gained increasing interest during last years, especially as application in the manufacturing of some components for: automotive, aerospace and electrical appliances for niche productions. Different studies have been also done to determine the optimal forming parameters making an extensive use of FEA. In the hydroforming process a blank sheet metal is formed through the action of a fluid and a punch. It forces the sheet into a die, which contains a compressed fluid. Many studies have been focused on the analysis of process and geometric parameters influence about the hydroforming process of a single product with main dimensions till to 100 mm. In this paper the authors describe the results of an experimental activity developed on two different large sized products obtained through sheet metal hydroforming. Different geometric and process parameters have been taken into account during the testing phase to study, in particular, the punch radius influence on the process feasibility. An ANOVA analysis has been implemented to study the influence of geometrical and process parameters on the maximum hydroforming depth. Through this work it has been possible to verify that in the hydroforming process of large size products geometry and, in particular, punch radius, are some of the main factors that influences the feasibility of the products. Different considerations can be made about the effects of the blankholder force and the fluid pressure on the maximum hydroforming depth. As further developments, the authors would perform a numerical study in order to enlarge the knowledge of the process design space to other possible values of the punch radius.

Due to the widespread use of highly automated machine tools, manufacturing requires reliable models and methods for the prediction of output performance of machining processes. The prediction of optimal machining conditions for good surface finish and dimensional accuracy plays a very important role in process planning. The present work deals with the study and development of a surface roughness prediction model for machining Al7075-T6, using Response Surface Methodology (RSM). Machining operations of work pieces made by Al7075-T6 covering a wide range of machining conditions have been carried out with by flat end mill with four teeth made by High Speed Steel. A RS model, in terms of machining parameters, was developed for surface roughness prediction using the Radial Basis Functions (RBF) technique. This model gives the process response sensitivity to the individual process parameters. An attempt has also been made to optimize the surface roughness prediction model using Genetic Algorithms (GA).

The NESSiE Collaboration has been setup to undertake a conclusive experiment to clarify the muon- neutrino disappearance measurements at short baselines in order to put severe constraints to models with more than the three-standard neutrinos. To this aim the current FNAL-Booster neutrino beam for a Short-Baseline exper- iment was carefully evaluated by considering the use of magnetic spectrometers at two sites, near and far ones.

Sheet hydroforming has gained increasing interest during the last years, especially as application in the manufacturing of some components for automotive, aerospace, and electrical appliances[1,2]. Many parameters influence the process of sheet hydroforming, one of them is the pre-bulging[3]. Different studies have been also done to determine the optimal forming parameters through FEA[4,5]. In the case of sheet hydromechanical forming process the blank is first placed on the lower die (a fluid chamber combined with draw ring) and then, after sealing the blank between blank holder and draw ring, punch progresses to deform the blank[6]. Pressure of the fluid chamber is also increased simultaneously with the punch progression[7]. In this paper, the pre-bulging effect on active hydromechanical deep drawing process has been investigated experimentally and numerically. Pre-bulging includes two parameters: pre-bulging height and pre-bulging pressure, which influence the forming process significantly[3]. Numerical simulations and experimental tests were carried out for a given shape to investigate the pre-bulging effect on the maximum hydroforming depth. During this activity, the authors have verified that the low numerical – experimental accuracy detected it was caused also by the simulation of the pre-bulging phase. The authors have analyzed the problem to define a correct procedure to simulate the pre-bulging phase. From this point of view, nine different levels of pre-bulging (taking into account the level equal to zero also) have been tested to experimentally calculate the Thickness Percentage Reduction (TPR) at the maximum pre-bulging height. For each level, the experiment has been conducted two times for a total number of eighteen experiments. The experimental TPR values have been compared with the numerical ones reaching a good accuracy only in the case of pre-bulging height greater than forty millimeters. The experimental activity has given a valid contribution to improve the simulation models reliability and to obtain useful information on the process itself. The effects of pre-bulging on the process performance are also discussed.

Finite element analysis (FEA) is a powerful tool to evaluate the formability of stamping parts during process and die design development procedures. However, in order to achieve good product quality and process reliability, FEA application has to be performed many times exploring different process parameters combinations. Meanwhile, it is very difficult to perform an exhaustive process design definition when many parameters play a fundamental role to define such a complex problem. So, under the needs of reduction in: design time, development cost and parts weight, there is an urgent need to develop and apply more efficient methods in order to improve the current design procedures. For a generic component it is clear how its shape, among several parameters, has a direct influence on its feasibility. Starting from this assumption, the authors have developed a new approach grouping components upon their shapes analyzing component formability within a given “component family”. Nowadays, it exists only a process designer “sensitivity” that produces a ranking upon shape/feasibility ratio. Having as reference industrial test cases, the authors have defined appropriate shape parameters in order to have dimensionless coefficients representative for the given geometries. In particular, the components have been classified using a parameters set defining similarity families: related to geometrical aspects and to constitutive material. From the geometrical point of view the following parameters have been defined: family name, shape factor, punch radius-thickness ratio, die radius-thickness ratio, while for the constitutive material a code has been defined. FEA has been extensively used in order to: define, investigate and validate each shape parameter with a proper comparison to the macro feasibility of the chosen component geometry. The feasibility configuration definition, for a given shape, has been made through an appropriate study of the influence of each process variable on the properly process performances.

The increasing application of numerical simulation in metal forming field has helped engineers to solve problems one after another to manufacture a qualified formed product reducing the required time [1]. Accurate simulation results are fundamental for the tooling and the product designs. The wide application of numerical simulation is encouraging the development of highly accurate simulation procedures to meet industrial requirements. Many factors can influence the final simulation results and many studies have been carried out about materials [2], yield criteria [3] and plastic deformation [4,5], process parameters [6] and their optimization. In order to develop a reliable hydromechanical deep drawing (HDD) numerical model the authors have been worked out specific activities based on the evaluation of the effective stiffness of the blankholder structure [7]. In this paper after an appropriate tuning phase of the blankholder force distribution, the experimental activity has been taken into account to improve the accuracy of the numerical model. In the first phase, the effective capability of the blankholder structure to transfer the applied load given by hydraulic actuators to the blank has been explored. This phase ended with the definition of an appropriate subdivision of the blankholder active surface in order to take into account the effective pressure map obtained for the given loads configuration. In the second phase the numerical results obtained with the developed subdivision have been compared with the experimental data of the studied model. The numerical model has been then improved, finding the best solution for the blankholder force distribution.

The machining processes simulation are commonly used by manufacturing industries in order to produce high quality and very complex products in a short time. These machining processes simulation include large number of input parameters which may affect the cost and quality of the products. Selection of optimum machining parameters in such machining processes is very important to satisfy all the conflicting objectives of the process. There are two options to choose the optimal cutting parameters for a given economic objective. The first one is concerned with the need of a machine expert that manually selects the machining parameters on the basis of its own experience and by means of a proper machining handbook. That way generates many uncertainties and drawbacks in terms of efficiency of solutions and time/cost requirements. As an alternative to the above mentioned approach, many research efforts have been made to state a comprehensive mathematical model of a turning process that, in practice, entails a set of cutting constraints to be handled. Machining optimization problems become tricky whenever a given objective function must be optimized with respect to a large number of constraints. This paperwork is focused about the generation of an automated optimization procedure, for turning processes of nickel superalloys, under certain process conditions. For the automated optimization procedure the response surface methodology (RSM) has been used to detect the influence of the process variables on its performances.

Le tecnologie che sfruttano metodi di rilevamento senza contatto sono sempre più utilizzate per migliorare l’efficienza dell’ispezione qualità in ambito manifatturiero. E’ evidente come, i recenti progressi dei sistemi di scansione laser e di visualizzazione hanno fatto si che sia possibile migliorare anche l’efficienza del controllo statistico dei processi di produzione. In questo articolo, gli autori presentano un sistema messo a punto per fornire in modo rapido misure di interesse delle features geometriche, che normalmente caratterizzano gli imbutiti da lamiere piane, integrato ad un modulo software di elaborazione delle misure per automatizzare l’ispezione della qualità e il controllo statistico di processo. Il sistema è costituito da componenti hardware e software appositamente sviluppati per le finalità di utilizzo della macchina messa a punto. La parte hardware è costituita da un’apparecchiatura a scansione laser e dall’attrezzatura che consente di riferire opportunamente i componenti al sistema durante la fase di misurazione. La parte software ha la finalità di generare part program di scansione ottimizzati in funzione della geometria del componente. Ciascuna scansione viene registrata e va a fare parte di un database che opportunamente organizzato consente di fornire informazioni utili per il controllo della qualità e il monitoraggio del processo di produzione preso in esame. Il sistema realizzato è stato progettato per consentire il rilevamento dei componenti a bordo linea. In questo articolo, gli autori, oltre a descrivere nello specifico le principali caratteristiche del sistema di acquisizione messo a punto, riportano i risultati del suo utilizzo su di un caso pratico dato dall’analisi di un lotto di produzione di un componente automobilistico ottenuto per imbutitura di lamiera piana.

The springback response on a stamped part, calculated by finite element analysis has been evaluated taking into account the uncertainty of some process conditions. In fact, in the simulation of sheet metal forming and springback, a traditional deterministic approach is not able to take into account the uncertain physical variations related to material characteristics, friction conditions, tools active surfaces status, etc. During sheet metal forming operations many different sources of non-controllable process variations usually display their effect leading to a degree of uncertainty in the final parts’ quality. For this reason, statistical tools and methods are increasingly being used in combination with FE numerical simulation. Then, if one of the purposes of process design is to study and model robustness or reliability of a given process in aleatory conditions, a CAE study might become a feasible way to do it. Today, the evaluation of the performances of a sheet metal stamping process, under uncertainty of the main variables, is possible using several commercial FEA packages. These software tools automatically allow the pre-emptive evaluation of the robustness of technological decisions and the process sensitivity to a random variation of uncontrollable parameters or conditions. For accurate calculations these innovative numerical approaches usually require a considerable amount of computational work both in terms of CPU time and in terms of number of CPUs. A specific experimental and numerical activity has been developed in order to better understand the technical capabilities in terms of process simulation in stochastic conditions.

Turning operations on complex components such as aircraft engines casings require the insert replacement at the end of each geometric feature manufacturing, independently from the actual tool wear level. For this reason, it is important to generally preserve tool integrity during the machining operation especially when the tool engages the workpiece (i.e., the most critical phase of operation). In fact, if the tool is damaged in this stage the quality of the whole operation is compromised. The attention has been focused on engage cutting conditions since the phenomenon that appears in this critical step plays a large influence on tool integrity and, consequently, on the quality of the operation. For this purpose a ring-workpiece of nickel-based super alloy (Inconel 718) has been machined in lubricated cutting conditions by using a CNC lathe with carbide coated tools. Two variables have been investigated in this study: the Depth Of Cut (DOC) and the approaching Engage angle (En), while the Cutting Speed (S), Feed-rate (F) and removed volume (Vrim) were kept constant. Both tool wear and cutting forces evolution during cutting have been analyzed.

Nickel super-alloys are characterized by: high temperatures resistance, high hardness and low thermal conductivity. For this reason they are widely used in critical operating conditions. However, due to their excellent mechanical properties, nickel super-alloys are hard to machine. Tool wear is a major problem in nickel super-alloys machining; the high temperature at the tool rake face is a principal wear factor. Flank wear is the most common type of tool wear; it offers predictable and stable tool life evaluation. In this work, the authors present a flank wear evaluation in Inconel 718 turning, in order to develop a predictive model for CAM optimization. An appropriate database has been developed thanks to an experimental activity (V-B as a function of: the cutting time T, cutting speed S and feed rate F). The objective of the optimization procedure is to maximize the Material Removal Rate (MRR) under the constraint represented by the flank wear limit. The developed procedure operates directly on the part program code, using the original one as starting point for the application of the knowledge about the wear behaviour. After the optimization phase the given output is represented by a new part program code obtained in accordance with: the maximum MRR within the respect of the wear limit

The present invention pertains to a methodology for the identification and traceability of materials in industrial process, with particular focus on the traceability of leather and leather-like materials throughout the manufacturing process of leather or leather-like products. Said methodology comprises, at least, the employment of the following: identification markers (3); a method for permanently embedding the markers inside the item (2) to be traced; a device for generating an electromagnetic signal to be used as stimulus for the marked material; a device for acquiring the response of the marked material to the applied stimulus; and a device for recording the aforementioned response.