Papers by Stefano Tornincasa
Lecture Notes in Mechanical Engineering, 2016
3D face was recently investigated for various applications, including biometrics and diagnosis. D... more 3D face was recently investigated for various applications, including biometrics and diagnosis. Describing facial surface, i.e. how it bends and which kinds of patches is composed by, is the aim of studies in Face Analysis, whose ultimate goal is to identify which features could be extracted from three-dimensional faces depending on the application. In this study, we propose 54 novel geometrical descriptors for Face Analysis. They are generated by composing primary geometrical descriptors such as mean, Gaussian, principal curvatures, shape index, curvedness, and the coefficients of the fundamental forms. The new descriptors were mapped on 217 facial depth maps and analysed in terms of descriptiveness of facial shape and exploitability for localizing landmark points. Automatic landmark extraction stands as the final aim of this analysis. Results showed that the newly generated descriptors are suitable to 3D face description and to support landmark localization procedures.
Lecture Notes in Mechanical Engineering, 2016
Indirect estimation of the stiffening effect caused by the fitting process of an automotive wheel... more Indirect estimation of the stiffening effect caused by the fitting process of an automotive wheel is hereby presented to detect optimal interference of automotive steel wheels. The effects are related to components and assembly characteristics, such as masses and natural frequencies. Both the components of the wheel, which are disc and rim, are subject to generalised tolerances and uncertainties, mainly related to elasto-plastic material properties, dimensional and geometrical tolerances and manufacturing process parameters. Taking into account the theoretical change in the dynamic properties of a pre-stressed structure with respect to its non-stressed condition, the stiffening effect caused by the fitting process is expected to bring consequences on the natural frequencies of particular and representative modes of the assembly. Moreover, the dynamic behaviour of the assembly can be related to the one of the two separate components, in order to improve the indirect estimation of the pre-stressed condition. The methodology is developed starting from numerical and experimental modal analysis, building a meta-model based on these training data, then evaluating the performance of that on a production wheel case. The optimal interference fit estimations are tested on a standard steel wheel for the Iveco Ducato commercial vehicle. Then to evaluate the robustness of the method, the meta-model is used for a compact spare tyre of a saloon car.
Today's virtual environments are expected to be distributed to allow collaboration for common... more Today's virtual environments are expected to be distributed to allow collaboration for common purposes. However, they must ensure a high level of operative efficacy to the user, especially in an open context with unknown man-in-the-loop event occurrence. This paper presents how the Distributed Virtual Environment Collaboration Model could be a right and efficient innovation in the archaeological content.
In the automotive industry a significant part of research is dedicated to design and produce bett... more In the automotive industry a significant part of research is dedicated to design and produce better products. The unavoidable presence of uncertainties in manufacturing processes and structural parameters leads to the necessity to develop stochastic models able to correctly represent physical behaviours. This paper presents numerical and experimental investigations on the effects of the fitting process on the stress/strain map of assembled automotive rim-disk systems. Different strategies of geometrical decomposition are used to condense large volumes of data by retaining essential information for the whole design process including not only manufacturing pre-stresses and operational loads but also dimensional tolerances of mating parts by means of a probabilistic model. Efficient approaches are used to identify the relative importance of input factors on the output uncertainties. A real test case of a wheel assembly is presented and discussed.
The Journal of Strain Analysis for Engineering Design, 2014
This article presents a methodology for the treatment of uncertainty in nonlinear, interference-f... more This article presents a methodology for the treatment of uncertainty in nonlinear, interference-fit, stress analysis problems arising from manufacturing tolerances. Image decomposition is applied to the uncertain stress field to produce a small number of shape descriptors that allow for variability in the location of high-stress points when geometric parameters (dimensions) are changed within tolerance ranges. A meta-model, in this case based on the polynomial chaos expansion, is trained using a full finite element model to provide a mapping from input geometric parameters to output shape descriptors. Global sensitivity analysis using Sobol’s indices provides a design tool that enables the influence of each input parameter on the observed variances of the outputs to be quantified. The methodology is illustrated by a simplified practical design problem in the manufacture of automotive wheels.
Aim of this paper is to present the concept of "industrial incubator" and its role for the develo... more Aim of this paper is to present the concept of "industrial incubator" and its role for the development of innovative Small and Medium Enterprises (SME's). Analyzing different incubator typologies the paper focus its attention on the reason why different incubation strategies could be implemented. Moreover the paper presents which are the main parameters that characterize an incubator structure and how the different incubation methodologies can answer selectively to market needs. The last part of the paper give a concrete view of the theoretical aspects cited presenting the incubator experience developed in Zenica (Bosnia Herzegovina.
Product design and manufacturing are all intrinsically collaborative processes. From conception a... more Product design and manufacturing are all intrinsically collaborative processes. From conception and design on through to project completion and ongoing maintenance, all points in the lifecycle on any product involve the work of fluctuating teams of designers, suppliers and customers. For this reason companies are in the process of creating a distributed design and manufacturing environment that enables integrated product, processes, and protocols development, finding effective methods for communication and sharing of information throughout the entire enterprise and the supply chain. Actually the ownership of the 3D models management tecnologies is stiill linked with the 3D CAD propritary even if the new trend is moving in the direction of new standard and technologies based on World Wide Web platforms. This new tendency tryes to extend the life of 3D product data moving these design information downstream thorough the entire product lifecycle. Unfortunately the actual lack of a unique 3D web-based standard has stimulated the growing up of a lot of proprietary and open source standards and consequently a production of an incompatible information exchange over the WEB. The paper proposes a structured analysis of web-based solutions, trying to identify the most critical aspects to promote a unique 3D digital standard model capable of sharing product and manufacturing data more effectively-regardless of geographic boundaries, data structures, processes or computing environment.
During the post-manufacturing life-cycle(assembling, packaging,…) the object surface could intera... more During the post-manufacturing life-cycle(assembling, packaging,…) the object surface could interact with other surfaces modifying its morphology with the introduction of local damages (scratches, bumps,…). Following quality principles and especially working with aesthetic components it is very important to detect these defects on the objects surface in order to fix it and to grant to the costumer a acceptable product. While for elementary geometries the inspection procedure are already standardized, working with sculptured ones (FREE-FORM), typical of the aesthetic components, the shape inspection strategies are not so known. In fact normally working on single components the inspection phase can be implemented manually by an expert operator that develop a complete visual inspection of the surface. But moving the attention on automated production lines this manual approach has to be substituted by an automatic one. So starting from the experience developed with reverse engineering and 3D scanner systems this work wants to propose an automated inspection strategy based on a segmentation reverse engineering strategy.
Biosystems Engineering, 2015
Anisotropic material properties Three point bending test FEM In order to improve the performance ... more Anisotropic material properties Three point bending test FEM In order to improve the performance of shelling machines, and to enhance the numerical modelling of anisotropic behaviour of hazelnuts shells, the mechanical properties of shells are useful experimental data. A procedure to obtain an effective numerical model and to calibrate anisotropic material properties by means of experimental testing is described. The procedure was applied to a commercial variety of Italian hazelnuts and the mechanical properties were experimentally obtained for shell on specimens obtained from conform hazelnuts. The numerical finite element model investigates single and double curvature geometry simulation performance of the shell specimens.
Purpose: The study proposes a structured methodology for soft-tissues landmarks formalization in ... more Purpose: The study proposes a structured methodology for soft-tissues landmarks formalization in order to provide a methodology for their automatic identification. Method: Working in the Differential Geometry domain, through the Coefficients of the Fundamental Forms, the Principal Curvatures, Mean and Gaussian Curvatures and also with the derivatives and the Shape and Curvedness Indexes, a Matlab® algorithm for extracting nine landmarks is built. Each landmark is unique for the behaviour of these geometrical descriptors in correspondence of its zone of interest. This particular behaviour of the descriptor is used to localize each landmark and for extracting it. Result: Nine landmarks were extracted for each of the seventy-nine faces of our database. Results were shown to an expert, a maxillofacial surgeon, who confirmed their correctness. So, the Matlab® algorithm elaborated for the landmarks extraction correctly works for all of them. Discussion & Conclusion: This research provided...
Conference Proceedings of the Society for Experimental Mechanics Series, 2014
In this paper experimental investigations of interference fit effects on the dynamic behaviour of... more In this paper experimental investigations of interference fit effects on the dynamic behaviour of assembled wheels are provided. The performed analyses on the automotive components take into account manufacturing pre-stresses and dimensional tolerances of mating parts.
Journal of Sound and Vibration, 2013
ABSTRACT This paper presents the application of semi-active control for optimising the power harv... more ABSTRACT This paper presents the application of semi-active control for optimising the power harvested by an electro-mechanical energy harvester. A time-periodic damper, defined by a Fourier series, is introduced for energy harvesting in order to increase the performance of the device. An analytical solution for the transmissibility and the average absorbed power is derived based on the method of harmonic balance. The coefficients of the semi-active model are optimised to maximise the harvested power. The harvested power from the optimum periodic time-varying damper at a particular frequency is compared and is shown to be greater than that from an optimum passive damper and a semi-active on-off damper not only at that particular frequency but also at other frequencies. In addition, the performance of the optimised periodic time-varying damper is also compared with an arbitrary semi-active time-periodic damper, which has the same transmissibility at resonance. An optimisation is carried out to maximise the power in a frequency range and the optimum damper is derived as a function of the excitation frequency. The numerical results are validated with the analytical approach.
Journal of Intelligent Material Systems and Structures, 2011
This article presents multidisciplinary optimization methods applied to the design and performanc... more This article presents multidisciplinary optimization methods applied to the design and performance evaluation of a magneto-mechanical energy scavenger for automotive wireless tire sensors. Optimal performance strictly depends on source characteristics, volume, weight and power density targets, energy scavenger typology, technological and manufacturing capabilities, optimization and reliability of performance, environment requirements, and so on. Thus an optimization study has been conducted on equivalent viscous damping due to strong magneto-electrical-mechanical coupling. To do this, an optimization tool has been developed that maximizes the power output in specific working conditions by varying the number and size of coils.
International Journal of Adhesion and Adhesives, 2014
ABSTRACT The adhesive bonding technology can be used in combination with other traditional joinin... more ABSTRACT The adhesive bonding technology can be used in combination with other traditional joining methods, such as mechanical fastening techniques (e.g. rivets or bolts) or welding techniques, generating a hybrid joint. Hybrid adhesive joints are designed to exploit the advantages of the different techniques and, if possible, overcome their drawbacks. This study focuses on the interference fitted/adhesive bonded joining technique. This method consists in two cylindrical components coupled together by inserting one into the other, after having placed an adhesive on the mating surfaces. This hybrid joint, generally realized by exploiting acrylic anaerobic systems, has been studied to evaluate the interaction between the tensile field of the components (at the interference level) and the adhesive strength under both static and dynamic loading conditions. Notwithstanding this, the contributions of the adhesive and the interference on the performance of the final joint are still not completely clear. The aim of this research is then to further study the factors affecting the resistance of this hybrid joint. Hub-shaft samples, joined by means of a press fit, were tested under an axial push out load. Hybrid joints were compared to both adhesive joints in clearance conditions and interference joints. In particular, different levels of interference were analyzed in order to clarify the role played by the tensile field between the hub and the shaft, and the influence of the friction effects between them. Numerical simulations were also employed to support the experimental data in the evaluation of the behavior of the adhesive and its relation with all the phenomena influencing the hybrid system. It was found that tribological phenomena played an important role in governing the mechanical behavior of the unbonded samples, while they can be considered negligible in presence of the adhesive. The correlation between bonded and unbonded press-fitted joints was investigated pointing out that the maximum strength of the hybrid joint is mainly related to the resistance of the epoxy adhesive.
IEEE Transactions on Magnetics, 2010
This paper presents a multi-physic modeling of an electromechanical energy scavenging device. A p... more This paper presents a multi-physic modeling of an electromechanical energy scavenging device. A permanent magnet, connected to the inner liner of a tyre, is accelerated along a guide by the tyre deformation during car motion; by interacting with coils it generates a power which is conditioned by a proper electronic interfaced to an external load. The energy conversion process takes into account the simulation of different phenomena like: dynamic behavior of the seismic mass, electromagnetic coupling between moving mass and coils, transfer of the generated power to an external load by means of a nonlinear circuit interface. An integrated model of the cascaded energy steps is developed inside the Simulink environment. A good agreement is found in the comparison between theoretical model and experiments. The accurate modeling of the energy conversion device is a breakthrough in the modeling of these kinds of devices and allows to reach interesting power/volume ratios: small dimensions (about one cubic centimeter) and relatively high power output (more than one milliwatt).
Computers in Industry, 2008
From a theoretical point of view, people are used to think that the adoption of innovative busine... more From a theoretical point of view, people are used to think that the adoption of innovative business solutions, for optimizing the product lifecycle, should always guarantee a sufficient return on the investment (ROI), even if the concrete benefits that the investment has given to the company are sometimes difficult to evaluate. Looking at the technical literature it is possible to find a lot of ROI 's estimation metrics for the evaluation of business strategies, even if after the analysis of the theorical concepts no one faces with a real implementation of the methodology proposed. This paper proposes a solution, based on the Key Performance Indicator (KPI) method, for evaluating the benefits introduced by the adoption of a PLM tool in a one of a kind company. The methods have been validated with its implementation into an Aerospace and Defence company (Alcatel Alenia Space), highlighting the improvement created by the implementation of the PLM solution in the every day activities and showing the system's contribution for some key-process as Configuration, Change and Documentation.
Knowledge is embedded in people and unlike information, knowledge creation occurs in a process of... more Knowledge is embedded in people and unlike information, knowledge creation occurs in a process of social interaction. As our service-based society is evolving into a knowledge-based society, there is an acute need for more effective collaboration and more effective knowledge sharing systems for use by geographically scattered people. Starting from the work made with the Leonardo da Vinci Project "3DWebEPL", the paper proposes a structured analysis for investigating the use of Web 3D components and standards for e-Learning purpose in the product development context.
Uploads
Papers by Stefano Tornincasa