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VALERIO MANGERUGA

Ricercatore t.d. art. 24 c. 3 lett. A
Dipartimento di Ingegneria "Enzo Ferrari"

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Pubblicazioni

2024 - Investigation on the Low Cycle Thermal Fatigue of a Hybrid Power Unit Transmission Clutch [Relazione in Atti di Convegno]
Barbieri, Saverio Giulio; Mangeruga, Valerio; Piergiacomi, Andrea; Giacopini, Matteo
abstract

A numerical methodology for the thermal-structural assessment of a clutch for a high-performance hybrid power unit is proposed. Clutches are commonly adopted in internal combustion engines to connect the crankshaft to the gearbox. However, the specific clutch under investigation is employed for the coupling between the electric motor and the engine transmission primary shaft in a P2 hybrid architecture. In this specific configuration, the clutch may be activated and deactivated frequently to maximise the efficiency of the power unit depending on the required output torque and on the particular control strategy developed. As a consequence, the thermal loads insisting on the clutch may differ with respect to the ones encountered in a typical full combustion architecture. The results of the presented research show the great influence of the thermal deformation on the stress state of this component, and the onset of possible failure due to low cycle fatigue phenomena is detected. In addition, the influence of different modelling strategies is considered.

2023 - Development of an Experimental/Numerical Validation Methodology for the Design of Exhaust Manifolds of High Performance Internal Combustion Engines [Articolo su rivista]
Lorenzini, Mariano; Giulio Barbieri, Saverio; Mangeruga, Valerio; Giacopini, Matteo
abstract

Several typical failure modes in the exhaust manifold of an internal combustion engine are commented on. In particular, thermal loading and the related thermal fatigue damage mechanism are addressed. The component under investigation is a cast exhaust manifold including the turbine involute. Finite Element simulations are performed, and a numerical methodology is presented to interpret and understand the observed failures, with the aim of developing a useful tool to virtually validate the component, before the manufacturing phase. The Finite Element analysis closely mimics the experimental validation procedure that considers several heating and rapid cooling cycles to simulate typical engine operating conditions. A static mechanical characterization at high temperatures of the materials involved is carried out, aimed at identifying a suitable alloy and its mechanical characteristics useful for feeding the numerical models. The developed design methodology proposes a damage criterion for thermal fatigue investigation, considering the elastoplastic behaviour of the material when subjected to high temperature cycles. In particular, the accumulated equivalent plastic strain range for a single thermal cycle (ΔPEEQ) is used, following the Ferrari expertise. The methodology appears to be well correlated with the experimental evidence, thus limiting the number of tests necessary for the approval of the component.

2023 - Effect of the Thermal Mean Stress Value on the Vibration Fatigue Assessment of the Exhaust System of a Motorcycle Engine [Articolo su rivista]
Barbieri, Saverio Giulio; Mangeruga, Valerio; Giacopini, Matteo; Callegari, Marco Severino; Bagnoli, Leonardo
abstract

The exhaust manifold of a high-performance motorcycle engine is subjected to combined thermal and vibrational loadings. In this research, the whole fatigue assessment of an exhaust manifold is addressed. First, a classic low-cycle fatigue analysis is performed. Then, a specific methodology for determining the fatigue cycle of components subjected to thermal and vibration loadings is developed and presented in a way that possible damages can be evaluated. The results are post-processed and the damage caused by fatigue cycles is computed referring to the Wöhler curve of the material using the Dirlik approach.

2023 - Finite Element Analysis of the Influence of the Assembly Parameters on the Fretting Phenomena at the Bearing/Big End Interface in High-Performance Connecting Rods [Articolo su rivista]
Renso, Fabio; Barbieri, Saverio Giulio; Mangeruga, Valerio; Giacopini, Matteo
abstract

Fretting fatigue is a well-known and dangerous damage mode that occurs on the mating surfaces of mechanical components, mainly promoted by a combination of stress distribution, contact pressure distribution, and relative sliding (micro)motion between the surfaces. However, predicting this mechanism is challenging, necessitating specific studies for each assembly due to variable influences. This article presents a methodology for evaluating fretting fatigue damage at the contact between a titanium connecting rod big end and the bearing, adopting the Ruiz parameter as a quantifying damage index. For this purpose, a thermal-structural finite element model is prepared. In particular, the machining and assembly of the split conrod big end are simulated, considering thermal effects. A full engine cycle is first simulated, and results are used for identifying critical instants to be considered for accurate yet computationally efficient calculations. The dependence of fretting fatigue on three factors is studied: bearing crush, bolts tightening torque, and friction coefficient between the big end and the bearing. In summary, the damage increases with a higher crush and friction, while tightening torque has marginal effects. Following a 20% increase in crush height, a corresponding 10% rise in the Ruiz parameter is observed. Conversely, reducing the crush height by 20% leads to an approximately 8% decrease in the Ruiz parameter. When the influence of the bolt preload is taken into account, only a marginal 1% increase of the Ruiz parameter is recorded despite a 30% rise in preload. Evaluating the impact of the friction coefficient on the Ruiz parameter reveals an almost linear relationship. These findings suggest that adjusting the screw preload can enhance the hydrodynamic behavior of the bearing without exacerbating fretting. Furthermore, exploiting the linear correlation between Ruiz and the friction coefficient allows for the generalization of results obtained with specific coefficient values. This methodology can, therefore, serve as a valuable reference for adjusting different variables during the initial design phases of a four-stroke internal combustion engine’s dismountable connecting rod.

2023 - Influence of the crankshaft dynamic phenomena on the fatigue behaviour of a transmission chain in a hybrid power unit [Relazione in Atti di Convegno]
Mangeruga, Valerio; Renso, Fabio; Raimondi, Francesco; Barbieri, Saverio Giulio; Giacopini, Matteo
abstract

This paper is part of an activity related to a specific hybridization process for an existing and commercialized motorcycle engine. The electric motor is mechanically connected to the engine using the original valvetrain transmission chain leading to a P0 hybrid architecture. The aim of this work is to analyse the structural behaviour of the chain now used as torque transmission device. Although on one side the maximum torque of the electric motor determines a stress state on the chain below its fatigue limit, on the other side, the dynamic behaviour of the system strongly influences the maximum stress on the chain. In fact, the main source of load on the chain derives from the torsional oscillation of the system. Engines rotational speed irregularity can be easily estimated through common analytical approaches which consider the contribution of combustion and inertial forces on the instantaneous torque produced by the crank mechanism and the overall inertia of the moving parts. However, more detailed lumped-parameters and Multibody dynamic models are here developed in order to estimate the actual instantaneous engine speed taking into account the arising of possible high order vibration phenomena. Specifically, the influence of the torsional vibration behaviour of the internal combustion engine isinvestigated on the resulting stress on the chain. Finally, the structural chain integrity is assessed by performing a fatigue analysis considering the actual operating conditions.

2023 - Influence of the pressure gradient during combustion on the fatigue behaviour of an internal combustion engine piston [Relazione in Atti di Convegno]
Bianco, Luigi; Barbieri, Saverio Giulio; Mangeruga, Valerio; Giacopini, Matteo; Perez, Fabrizio Fontana
abstract

In recent years, increasing demands for higher power density, lower emission and lower fuel consumption drive the research on internal combustion engines towards the adoption of innovative types of combustion like Homogeneous Charge Compression Ignition, Spark Controlled Compression Ignition and Gasoline Direct Injection Compression Ignition. All these systems exhibit aggressive combustion strategies and, as a consequence, a high-pressure gradient can be encountered in the combustion chamber at the early beginning of the combustion process. On one hand, the specific value of the pressure gradient marginally affects the kinematic analysis of the engine piston and its primary axial translational motion. On the other hand, it can possibly affect its secondary motions, namely piston transversal motion and piston tilting. Therefore, to investigate the influence of the pressure gradient, a numerical approach capable to capture the whole piston dynamic behaviour is mandatory. In this contribution, different pressure profiles are taken into account and then employed in different Multibody analyses to understand the influence of the pressure gradient on the piston secondary motions. In particular, three different pressure profiles exhibiting an increasing gradient, but with the same total heat released, are considered. In addition, three different radial clearances between the piston and the cylinder liner are simulated for each pressure profile. So that, a total of nine Multibody analyses are performed. The results are then post-processed and the Dang Van high cycle fatigue safety factor contour plot on the piston is obtained for each configuration. The results show a dependency of the fatigue life of the piston on the pressure gradient, albeit no detrimental structural issues are detected for the different configurations analysed. The presented methodology represents a useful tool for the structural assessment of pistons when a first original safe combustion strategy is modified towards more efficient ones characterized by pressure profiles presenting a higher gradient.

2023 - Investigation via Finite Element Analysis of the Influence of Boiling on the Thermo-Structural Behavior of the Engine Head of a High-Performance Combustion Engine [Relazione in Atti di Convegno]
Piergiacomi, Andrea; Barbieri, Saverio Giulio; Renso, Fabio; Mangeruga, Valerio; Giacopini, Matteo
abstract

This paper presents a numerical methodology for studying the effect of boiling on the structural behavior of high-performance internal combustion engines. Boiling occurs when the portion of engine coolant in contact with hot walls reaches high temperatures and vapor bubbles form. While incipient vaporization of the coolant can promote additional cooling, excessive vapor can act as an insulator and lead to potentially dangerous high temperatures in the engine. Boiling is typically analyzed using Computational Fluid Dynamic Analyses, which are usually computationally intensive. In this study, the authors propose a Finite Element methodology that combines semi-empirical formulations, less demanding than Computational Fluid Dynamic models, with thermal Finite Element simulations to detect and manage boiling. Two different empirical formulations for boiling were employed, proposed by Garro and Chen respectively, and their results were compared. Three thermal analyses were conducted: the first neglected the effect of boiling, which leads to results inconsistent with the assumption of single-phase fluid, while in the second and third simulations, the occurrence of boiling and its effects were managed using the Garro and Chen formulations. The results showed a significant decrease in wall temperatures around the regions where boiling was detected and a parallel reduction of the thermal gradients inside the component. The two semi-empirical approaches for boiling estimation produced similar results, suggesting their substantial equivalence. Then, the temperature fields obtained were employed in structural Finite Element Analyses to evaluate the effects of boiling on the fatigue life of the engine head. In the structural analyses, the more uniform thermal field leads to a reduction of thermal deformations and to a different stress state, affecting the safety factor distribution. This methodology has the potential to be a suitable tool for detecting boiling and its effect during the early stages of engine design.

2023 - Numerical Investigation of the Dynamic Effects on the Fatigue Behaviour of a Transmission Chain in a Hybrid Power Unit [Articolo su rivista]
Mangeruga, Valerio; Renso, Fabio; Barbieri, Saverio Giulio; Giacopini, Matteo; Raimondi, Franceco
abstract

2023 - Oil jets piston cooling: A numerical methodology for the estimation of heat transfer coefficients and optimization of the piston temperature field through a genetic algorithm [Articolo su rivista]
Renso, Fabio; Giacopini, Matteo; Barbieri, Saverio Giulio; Mangeruga, Valerio
abstract

High-efficiency internal combustion engines need specific methodologies to be developed for the design improvement of the components. Predicting and reducing the thermal loadings on the parts are critical tasks to be addressed. This contribution focuses on the thermal management of the piston through oil jets. The operating temperature of the piston deeply affects its thermo-mechanical behavior, thus possibly jeopardizing the structural integrity of the component. The design of piston cooling jets is usually addressed through Computational Fluid Dynamics, which can guarantee accurate results, usually at a high computational cost. In this contribution, a faster tool is derived to grasp the effect of the cooling jets on the temperature of the piston. Empirical correlations are applied to predict the instantaneous heat transfer coefficients on the piston. The reciprocating motion of the piston is considered since it affects the interaction between the surface and the oil jets. Instantaneous coefficients are cycle-averaged and used to estimate the temperature of the piston through a Finite Element thermal analysis. Finally, an optimization code is developed to find the best jet configuration capable to minimize the temperature of the piston. This methodology is a powerful tool to select the optimal oil jet nozzles for piston cooling.

2022 - Influence of the thermal deformation on the lubricating performance of the piston-gudgeon pin interface in an internal combustion engine [Articolo su rivista]
Bianco, L.; Barbieri, S. G.; Mangeruga, V.; Giacopini, M.; Capoccia, G.
abstract

This contribution describes a methodology to evaluate the influence of bellmouth profiles on the elastohydrodynamic behaviour of the contact interface between the gudgeon pin and the piston of a high-performance internal combustion engine. First, a thermo-mechanical simulation is performed to evaluate the piston bosses thermal strains. Consequently, a Multibody elastohydrodynamic model is set up to evaluate the tribological behaviour of this lubricated interface considering a perfectly cylindrical shape of the piston bosses and their thermal deformation. Then, a preliminary bellmouth profile is adopted and a second Multibody model is performed. Nevertheless, the results, together with issues encountered analysing some tested pistons, suggest that modifications of piston bosses have to be introduced. Finally, an optimised bellmouth geometry is proposed and analysed.

2022 - Structural Analysis of the Forming Process for Hairpin Windings for Electric Motor Applications: Torsional-Flexural Instability Issues [Relazione in Atti di Convegno]
Barbieri, S. G.; Mangeruga, V.; Giacopini, M.; Mantovani, S.
abstract

Electric motor manufacturing technology is evolving due to automotive transport development. Besides, environmental issues and the need of CO2 emission reduction have led to an increasing demand for electric drives efficiency. Permanent magnet synchronous machines are widely employed for traction systems and distributed windings produced by using insert techniques are growing in popularity. These methods require preformed wires such as the well-known hairpin shape. The advantages of hairpins are discussed in the pertinent literature. In the present paper, the manufacturing process of a hairpin is investigated by analysing its mechanical behaviour via Finite Element simulations. In fact, many problems might occur during the forming of a hairpin, depending on the shape required. In particular, this study aims at describing the influence of the geometry of the wire cross-section on the resulting final shape of the formed hairpin. Suitable ranges of geometrical and manufacturing parameters are identified to avoid torsionalflexural instabilities.

2021 - The Effects of the Specific Material Selection on the Structural Behaviour of the Piston-Liner Coupling of a High Performance Engine [Relazione in Atti di Convegno]
Barbieri, Saverio Giulio; Mangeruga, Valerio; Giacopini, Matteo
abstract

The materials commonly employed in the automotive industry are various and depend on the specific application field. For what concern the internal combustion engines the choice is guided by the thermomechanical performance required, technological constraints and production costs. Actually, for high-performance engines, steel and aluminium are the most common materials selected for the piston and the cylinder liner manufacturing. This study analyses the effect of possible material choice on the interaction between piston and cylinder liner, via Finite Element analyses. A motorcycle engine is investigated considering two possible pistons: one (standard) made of aluminium and one made of steel. Similarly, two possible cylinder liners are considered, the original one made of aluminium and a different version made of steel obtained by simply thinning the aluminium component in order to obtain two structurally equivalent components. In particular, four possible combinations of coupling between piston and cylinder liner are identified, derived from the two variants of applied materials. The components theoretically necessary for the Finite Element model are the engine head, the engine block, the bolts, the gasket, the upper part of the crank mechanism and the cylinder liner. Nevertheless, a simplified methodology is employed to reduce the computational effort. This analysis makes it possible to evaluate gap and interference with respect to the material choice. A first proposal of the barrel shape and ovality of the steel piston is obtained starting from the original aluminium piston and the thermal field involved in the analysis. Besides, the presented methodology consists of a useful tool to estimate the stress field and the fatigue safety factor of the components involved. The results obtained with this methodology can guide the definition of the correct piston profile, temperature field and stress distribution estimation, as a function of the specific materials employed for piston-liner coupling.

2020 - A simplified finite element methodology for the structural assessment of an engine piston under dynamic loadings [Relazione in Atti di Convegno]
Barbieri, Saverio Giulio; Bianco, Luigi; Mangeruga, Valerio; Giacopini, Matteo
abstract

The piston slap strongly affects the structural integrity of engine pistons. This phenomenon is caused by the dynamic effects of the piston secondary motions, both horizontal translation and tilting. This occurrence amplifies the contact forces between the piston and the cylinder liner if compared to the ones calculated by using simple kinematic analysis. A numerical approach is therefore mandatory. This paper presents a numerical methodology to predict the influences of piston secondary motions on the piston fatigue life. A combined Multy-Body/FEM strategy is developed to obtain truthful forecasts saving computational effort. First, Multi-Body simulations are performed to evaluate the piston secondary motions and the loadings involved. The most critical instants are retrieved and equivalent lateral accelerations are derived in order to prepare simplified quasi-static Finite Element models. Then, the stress field and the resulting fatigue safety factor distribution of the piston are obtained. The methodology reveals itself to be a useful tool to predict the fatigue life of pistons capable of limiting the computational effort and supporting the dimensioning of engine components during the early stages of the design process.

2020 - Investigation on the Dynamic Behaviour of a Torque Transmission Chain for an Innovative Hybrid Power Unit Architecture [Articolo su rivista]
Mangeruga, V.; Giacopini, M.; Barbieri, S.; Russo, M.
abstract

In this contribution, the mechanical torque transmission between the Electric Motor (EM) and the Internal Combustion Engine (ICE) of a P0 architecture hybrid power unit is analysed. In particular, the system is made up of a brand new, single-cylinder 480cc engine developed on the basis of the Ducati 959 Panigale V90 2-cylinders engine. The thermal engine is assisted by a custom electric motor (30 kW), powered by a Li-Ion battery pack. The Ducati 959 Panigale engine is chosen because of its high power-to-weight ratio, and for taking advantage of its V90 2-cylinders layout. In fact, the proposed hybridization process considers to remove the vertical engine head and to replace it by the electric motor directly engaged to the crankshaft using the original valvetrain transmission chain, thus achieving a very compact package. This solution could be suitable for many V-type engines and it aims to obtain a small hybrid power unit for possible motorcycle/small vehicle applications. The original timing chain object of this study is a silent chain, which is commonly employed as a transmission component in hybrid power units because it can operate at high speeds transmitting high loads and ensuring noise reduction. For this reason, the aim of this study is to assess the possibility of using the original chain to couple the EM and the ICE. This investigation allows the replacing of the minimum number of components during the hybridization process leading to a real plug&go solution. Therefore, the mechanical behaviour of the chain is investigated performing a dynamic analysis of the whole crank mechanism. In particular, the original twin cylinders model considering the original valvetrain system is compared with the single cylinder model engaged with the EM. The dynamic analysis provides the maximum load on the single chain link in both configurations, allowing the evaluation of a relative fatigue safety factor.

2019 - A Simplified Methodology for the Analysis of the Cylinder Liner Bore Distortion: Finite Element Analyses and Experimental Validations [Relazione in Atti di Convegno]
Barbieri, Saverio Giulio; Giacopini, Matteo; Mangeruga, Valerio; Bianco, Luigi; Mastrandrea, Luca Nicolò
abstract

Advances in modern engines are becoming more and more challenging. The intense increase of thermal and mechanical loads, as a consequence of a higher power density, requires the improvement of the main couplings encountered between moving engine components. In this scenario, the cylinder liner/piston coupling plays a crucial role in terms of engine performance and durability, especially with regards to pollution emission and friction reduction. In this paper a numerical methodology is proposed, which aims at simplifying the Finite Element evaluation of the cylinder liner bore distortion in an eight-cylinder V-type four stroke turbocharged engine. Finite Element simulations are performed to obtain a virtual approval of the component geometry, in advance with respect to the component manufacturing. In particular, preliminary Finite Element analyses are developed which accurately follow the experimental procedure, where a single engine bank is coupled with a simplified test engine head. The Finite Element model is properly tuned in order to obtain the same cylinder liner distortion registered by experimental measurements. Further Finite Element analyses, both thermal and thermo-mechanical, are then performed to evaluate the cylinder liner distortion considering the actual engine head. In order to speed up the analyses, the engine head, the gasket, and the bolt tightening are subsequently substituted by pressure distributions mimicking the actual contact interactions. The methodology reveals itself to be well correlated with the experimental evidences and with the complete Finite Element model of the engine bank thus consisting in a useful tool for reducing the time necessary for the component approval. © 2019 SAE International and © 2019 SAE Naples Section. All rights reserved.

2019 - A finite element numerical methodology for the fatigue analysis of cylinder liners of a high performance internal combustion engine [Relazione in Atti di Convegno]
Barbieri, S. G.; Mangeruga, V.; Giacopini, M.; Laurino, C.; Lorenzini, M.
abstract

In this paper a numerical methodology is proposed, which aims at predicting the fatigue behaviour of engine cylinder liners in an eight-cylinder V-type four-stroke turbocharged engine. A preliminary kinematic and dynamic study of the crank mechanism is fulfilled in order to properly identify the load cycle that involves the cylinder liner. Finite Element analyses, both thermal and thermo-mechanical, are performed to evaluate the stress and the strain of the component. In particular, non-linear models are developed to mimic the piston-liner interaction when subjected to different loading conditions. A simplified approach is proposed in order to reduce the computational effort of the simulations. FEM results are then processed employing the multiaxial Dang Van fatigue criterion.

2019 - Design of a Hybrid Power Unit for Formula SAE Application: Packaging Optimization and Thermomechanical Design of the Electric Motor Case [Articolo su rivista]
Mangeruga, V.; Giacopini, M.; Barbieri, S. G.; Berni, F.; Mattarelli, E.; Rinaldini, C.
abstract

This paper presents the development of a parallel hybrid power unit for Formula SAE application. In particular, the system is made up of a brand new, single-cylinder 480 cc internal combustion engine developed on the basis of the Ducati "959 Superquadro" V90 2-cylinders engine. The thermal engine is assisted by a custom electric motor (30 kW), powered by a Li-Ion battery pack. The performance of the ICE has been optimized through CFD-1D simulation (a review of this activity is reported in a parallel paper). The main design goal is to get the maximum amount of mechanical energy from the fuel, considering the car typical usage: racing on a windy track. The Ducati "959 Superquadro" engine is chosen because of its high power-to-weight ratio, as well as for its V90 2-cylinder layout. In fact, the vertical engine head is removed and it is subsequently replaced by the electric motor directly engaged to the crankshaft using the original valvetrain transmission chain, thus achieving a very compact package. The mechanical behaviour of the original chain is investigated for this purpose. A specific electric motor case is then designed and manufactured via Additive Manufacturing technology, in order to include the chain housing, the electric motor cooling system and the lubrication system. Furthermore, the case flange is designed to perfectly fit to the original engine deck in order to allow the engine cooling circuit to match with the electric motor cooling circuit. Several types of circuit layout - around the stator - are analysed via CFD simulations comparing pressure drop and heat transfer coefficients. Finally, a thermo-structural analysis is performed in order to assess the mechanical strength of the electric motor case.

2019 - Development of a Hybrid Power Unit for Formula SAE Application: ICE CFD-1D Optimization and Vehicle Lap Simulation [Relazione in Atti di Convegno]
Mattarelli, E.; Rinaldini, C. A.; Scrignoli, F.; Mangeruga, V.
abstract

The paper reviews the CFD optimization of a motorcycle engine, modified for the development of a hybrid powertrain of a Formula SAE car. In a parallel paper, the choice of the donor engine (Ducati 959 Panigale: 2-cylinder, V90, 955 cc, peak power 150 HP at 10500 rpm, peak torque 102 Nm at 9000 rpm) is thoroughly discussed, along with all the hardware modifications oriented to minimize the new powertrain dimensions, weight and cost, and guarantee full reliability in racing conditions. In the current paper, the attention is focused on two main topics: 1) CFD-1D tuning of the modified Internal Combustion Engine (ICE), in order to comply with the Formula SAE regulations, as well as to maximize the power output; 2) simulation of the vehicle in racing conditions, comparison with a conventional combustion car and a full electric vehicle. The stock engine has been strongly modified, since the head of the vertical cylinder has been replaced by the electric motor, and the intake system of the other cylinder now includes a 20 mm restrictor. Despite these constraints, the tuned ICE is able to deliver more than 70 HP. Finally, the study shows that the hybrid car is not only more efficient (-26% of specific CO2), but also 1.48 s faster on each lap than the corresponding Combustion single seater.

2019 - On the strength weakening effect of stiffening ribs in the design of machine components [Capitolo/Saggio]
Strozzi, A.; Bertocchi, E.; Mangeruga, V.
abstract

The bending stress in beams may often be reduced by adding material to the cross section. In some paradoxical cases, however, the bending stress increases by adding material from zones far away, or close to, the neutral axis. Similarly, the bending stress of rectilinear or curved beams may often be reduced by adding ribs to the initial beam section. However, such ribs may sometimes cause a both undesired and unexpected stress increase, although they still produce a beneficial stiffening effect. The aim of this paper is twofold: A) to examine this unexpected result within the context of the paradoxical behaviour of some known beam sections, and especially of a recently noted paradox; b) to provide a preliminary rule of thumb for the mechanical design of ribs sometimes added to the outer surface of an eye, with particular regard to the small end of a connecting rod.

2018 - Design of an Additive Manufactured Steel Piston for a High Performance Engine: Developing of a Numerical Methodology Based on Topology Optimization Techniques [Articolo su rivista]
Barbieri, SAVERIO GIULIO; Giacopini, Matteo; Mangeruga, Valerio; Mantovani, Sara
abstract

Modern high performance engines are usually characterized by high power densities, which lead to high mechanical and thermal loadings acting on engine components. In this scenario, aluminum may not represent the best choice for piston manufacturing and steel may be considered as a valid alternative. In this article, a methodology involving optimization techniques is presented for the design of an internal combustion engine piston. In particular, a design strategy is preliminary investigated aiming at replacing the standard aluminum piston, usually manufactured by forging or casting, with an alternative one made of steel and manufactured via an Additive Manufacturing process. Three different loading conditions are employed for the topology optimizations setup. Optimization results are then interpreted and the various structural features of the steel piston are designed starting from the density distribution contour plots. Different Finite Element thermomechanical models are finally prepared in order to correct and validate the designed geometry.

2018 - Design of an Additive Manufactured Steel Piston for a High Performance Engine: Developing of a Numerical Methodology Based on Topology Optimization Techniques [Articolo su rivista]
Barbieri, S. G.; Giacopini, M.; Mangeruga, V.; Mantovani, S.
abstract

Modern high performance engines are usually characterized by high power densities, which lead to high mechanical and thermal loadings acting on engine components. In this scenario, aluminium may not represent the best choice for piston manufacturing and steel may be considered as a valid alternative. In this paper, a methodology involving optimization techniques is presented for the design of an internal combustion engine piston. In particular, a design strategy is preliminary investigated aiming at replacing the standard aluminium piston, usually manufactured by forging or casting, with an alternative one made of steel and manufactured via an Additive Manufacturing process. Three different loading conditions are employed for the topology optimizations set up. Optimization results are then interpreted and the various structural features of the steel piston are designed starting from the density distribution contour plots. Different Finite Element thermo-mechanical models are finally prepared in order to correct and validate the designed geometry.

2017 - A Design Strategy Based on Topology Optimization Techniques for an Additive Manufactured High Performance Engine Piston [Articolo su rivista]
Barbieri, Saverio Giulio; Giacopini, Matteo; Mangeruga, Valerio; Mantovani, Sara
abstract

In this paper, a methodology for the design of a motorcycle piston is presented, based on topology optimization techniques. In particular, a design strategy is preliminary investigated aiming at replacing the standard aluminum piston, usually manufactured by forging or casting, with an alternative one made of steel and manufactured via an Additive Manufacturing process. In this methodology, the minimum mass of the component is considered as the objective function and a target stiffness of important parts of the piston is employed as a design constraint. The results demonstrate the general applicability of the methodology presented for obtaining the geometrical layout and thickness distribution of the structure.