1,420 research outputs found

    Multibody parameter estimation: A comprehensive case-study for an innovative rear suspension

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    Numerical and virtual simulation of mechanical systems is a standard part of product development in the automotive sector, and multibody techniques are a consolidated tool to describe vehicle dynamics, elasto- kinematic behavior, handling, and comfort. To achieve high precision results as output of simulations, it is essential to provide the system with reliable data as input, and to accurately describe the vehicle and its subsystems. The task of gathering objective parameters to fully describe a vehicle can seem trivial to the stakeholders directly connected to a project, that can access detailed design data and a plethora of schemes and datasheets covering all subsystems of a vehicle. However, whenever this task regards benchmarking, prototyping, research projects or niche/low-volume products, data availability decreases drastically, and alternative forms of data acquisition become essential. This paper proposes a comprehensive overview of data gathering and experimental procedures used to reliably extract parameters of an existing vehicle using quick and accessible strategies. The analysis is based on a case-study project of an A-segment vehicle mounted with an innovative rear suspension scheme, whose behavior should be described by a dedicated elasto- kinematic multibody model as well as a full vehicle model for dynamic validation. The multibody model is based on Adams/Car with the inclusion of flexible elements, which is briefly described, while a closer focus is given to the experimental extraction of key features, such as: total mass, longitudinal and lateral position of the center of gravity, CoG height, wheel travel and wheel rate, shock-absorber damping coefficient, steering ratio, components inertia and flexible elements strain. The results obtained in the static and dynamic experimental validation suggest a good outcome from the methodology, that can be replicated on many kinds of vehicle modelling activities as an approachable and affordable experimental methodology for small projects

    Composite Control Arm Design: A Comprehensive Workflow

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    This paper presents a complete overview of the computational design of an advanced suspension control arm constructed of composite material for light weighting purposes. The proposed methodology presented in detail is split into 3 phases. Phase 1 or Vehicle Performance Simulation, in which basic modelling and a sensibility study is performed to better understand the advantages of unsprung mass reduction (compared to sprung mass reduction) with respect to the vehicle's vertical dynamics. It followed by the development and utilization of a multibody approach to evaluate the full-vehicle response to different dynamic maneuvers, such as harsh road imperfections, sine sweep steering, and double lane change tests. The impact of the improved suspension control arm is highlighted in detail, and the loads to which it is subjected are computed to serve as inputs for the successive phases. Phase 2 or Design and Calculation Phase, where a closer look is given to the structural side of the component, understanding the specific behavior of composite materials and performing modelling of the control arm, followed by fine tuning with Finite Element Method optimization techniques. This phase consists of a topology optimization, followed by composite topography free size, size, and shuffle optimizations to arrive upon the ideal part-layup, and guarantee the desired mechanical characteristics of the component. Lastly, Phase 3 or the Production Preparation closes the design process by generating the production processes, steps, constraints, and tooling for the correct realization of the innovative control arm in a real-world application. The tools presented in this paper were created to allow the design to be completed rapidly, thus defining a blueprint for a full workflow, from engineering request to product delivery, which can be applied to different vehicles and customer requests, representing an essential step forward to the consolidation of the use of composite materials for structural suspension components

    Validation of a numerical-experimental methodology for structural health monitoring on automotive components

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    In the recent years, the materials composing the traditional of aircrafts are being progressively replaced with lower density materials, as the Reinforced Plastics. The same trend has been highlighted in the Automotive field to assess the reduction of fuel consumption and CO2 emission. In order to achieve an optimization of maintenance a variety of on-board systems has been applied for on-line SHM based on piezoelectric transducers earned a particularly high interest for continuous monitoring on metallic and composite structures. The application of this system in automotive could enhance passenger safety, through the monitoring of the vehicle composite material structure health status. In this paper, six mathematical models for evaluating the electrical response of piezoelectric sensors have been implemented, with the aim of selecting the most effective model for damage identification. Experimental tests were carried out on three types of simpler specimens of different geometries made of different materials (steel, aluminum and carbon fiber). A correlation study has been carried on in order to support the positioning of sensors. The proposed numerical-experimental methodology is an essential foundation for the introduction of monitoring systems based on piezoelectric transducers in the Automotive sector

    City Car Drag Reduction by means of Flow Control Devices

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    In the past few decades, the automotive industry saw the development of several environment-friendly technologies, as high efficiency engines, lightweight materials, and low-rolling-resistance tires. Car body styling, together with aerodynamics, play an important role in resolving environmental issues by reducing drag force, which results in high fuel efficiency and lower energy requirements. The main objective of this study is the reduction of the aerodynamic resistance of a city-car prototype by means of flow control devices (air blow and air relief) located into the wheel arches. This work starts from the wind tunnel experimental tests of the baseline version of the XAM 2.0 vehicle, then, dedicated ducts are implemented into the model in order to reduce the turbulence of the front wheel well and the air-flow defection at the end of the sides of the car body. A CFD analysis is carried out in order to assess the effects of the introduced modifications: car shape is varied by CAS, for every modification CFD calculations are performed. A correlation between wind tunnel and CFD results is carried out validating the drag optimization, demonstrating the predictive capabilities of CFD analysis and a record-breaking drag coefficient

    Evaluation of maize germplasm based on zein polymorphism from the archipelago of Madeira

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    Zein polypeptides are a group of proteins that accumulate in maize endosperm during seed development, representing more than 60% of the total endosperm proteins in the mature seeds. To evaluate genotype variability of Madeiran maize germplasm, a biochemical study was conducted based on the prolamins of maize, zeins, extracted from endosperm meal of 43 populations of Zea mays L. maintained in the Germplasm bank of Madeira University along with the inbreed W64A which was used as a polymorphic zein polypeptide standard profile. The zein polymorphism of these 44 maize populations were compared using two different electrophoresis techniques, SDS-PAGE in 15% discontinuous polyacrylamide gel and Acid-PAGE in 10% continuous polyacrylamide gel. SDS-PAGE allowed up to 16 polypeptides to be identified with apparent molecular mass ranging from 28-kDa to 10-kDa. Acid-PAGE allowed up to 20 zein fractions to be identified. The data was submitted to principal component analysis (PCA) and canonical discriminate and similarity analysis. The SDS-PAGE zein polymorphism allowed us to detect 6 groups, assembling all maize populations and explaining 55.32% of all variability. The similarity analysis of zein patterns obtained by Acid-PAGE showed that among regional maize germplasm, 22.5 % of all population seems to be related and have a common ancestor. The ISOP71 seems to be the population more closed to the common ancestor and appears related with the remaining maize populations, excluding the ISOP125.The obtained results and the importance of zein polymorphism in the evaluation of maize germplasm from Madeiran Archipelago are discussedinfo:eu-repo/semantics/publishedVersio

    Estiolamento in vitro: uma alternativa para a produção de mudas micropropagadas de antúrio.

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    Fatty acid composition, TLC screening, ATR-FTIR analysis, anti-cholinesterase activity, and in vitro cytotoxicity to A549 tumor cell line of extracts of 3 macroalgae collected in Madeira

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    Three macroalgae collected at Madeira Island were included in this study to determine their potential for drug, nutraceutical, food, or supplement application. Fatty acid content was higher in Zonaria tournefortii (12.32 mg g−1 dw) with 16.58% of PUFAs, eicosapentaenoic acid (C20:5ω3), and arachidonic acid (20:4ω6) having concentrations of 2.59 and 1.17%, respectively. The anti-thrombogenic and anti-atherogenicity potential was higher for Z. tournefortii due to relevant fatty acids in the biochemical composition this macroalgae. Lipid classes were assessed in the lipid extract and neutral lipids (NL) were in higher yield in Asparagopsis taxiformis (51.16%) and lower in Z. tournefortii (26.96%). The glycolipids (GL) were between 36.03 and 16.11% in Z. tournefortii and Ulva lactuca. Phospholipids (PL) fraction varied from 35.91 and 31.60% in A. taxiformis and Z. tournefortii. TLC screening identified that U. lactuca contains phytol and cholesterol in its NL, digalactosyldiacylglycerol in its GL, and cardiolipin and L-α-phosphatidylcholine in its PL. Zonaria tournefortii contains phytol and cholesterol in its NL classes, and the PL classes contain L-α-phosphatidylethanolamine and 1-(3-sn-phosphatidyl)-rac-glycerol. The macroalgae A. taxiformis revealed cholesterol in its NL fraction and the same phospholipids as Z. tournefortii in its PL fraction. ATRFTIR analysis enabled a “fingerprint” spectra and important sulfation absorption bands were identified, revealing the functional polysaccharides within these macroalgae. Anti-cholinesterasic activity was assessed in A. taxiformis, with a low IC50 for AChE (8.92 ± 0.43 μg mL−1 ) and BuChE (13.96 ± 0.32 μg mL−1 ), demonstrating dual inhibitory activity, justifying the interest to identify the active principle which may be the scaffold of a novel drug.This work was financially supported by DemoBlueAlgae “Desenvolvimento de metodologias e optimização dos processos de cultivo e processamento de macroalgas para a indústria e economia azul” PROCiência 2020 (M1420-01-0247-FEDER000002);MACBIOBLUE “Proyecto demostrativo y de transferencia tecnológica para ayudar a las empresas a desarrollar nuevos produtos y procesos en el ambito de la Biotecnología Azul de la Macaronesia” (MAC/1.1b/ 086), program Interreg MAC 2014–2020; ARDITI - Regional Agency for the Development of Research Technology and Innovation (M14-20-09- 5369-FSE-000001-Doctorate in Business; Blue Iodine II “Boost Blue economy through market uptake an innovative seaweed bioextract for iodine fortification II”, grant agreement no. 733552, H2020-SMEInst2016-2017.info:eu-repo/semantics/publishedVersio
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