Engenharia Mecânica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/23
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8 resultados
Resultados da Pesquisa
- SCRUM applied to foundry simulation projects(2021-01-05) DE SÁ, D. A.; WILLIAN GOMES, C.; PAULIELI COLOSSETTI, A.; SCHMIDT, J.; RODOLFO ABRAHAM, E.© 2021 SAE International.Process simulation has a growing role in the casting industry, considered as an essential tool by most foundries that aim to develop systems that deliver quality parts, with the highest possible yield and lowest scrap rate. The challenges of performing casting simulation as part of tool construction projects for permanent molds are presented here. Real schedules from tooling companies are analyzed and their bottlenecks are explored. Using the concepts of agile project management and the Scrum framework applied to a cast part, it was possible to verify that integration between tool construction and simulation can increase quality and robustness with no impact to product development time.
- Test and Validation of Vehicle Vertical Dynamics in a Multibody Software(2015-09-05) AFONSO, B.; CHICUTA, W.; Roberto BortolussiCopyright © 2015 SAE International.This paper shows the elaboration of studies about the driver's comfort in a Baja SAE vehicle in different track conditions. The multibody model was designed in ADAMS VIEW software with full vehicle components aim evaluate frequencies, accelerations and displacements in any part of the vehicle. Several tests and measurements were made to acquire springs, dampers and tire data to ensure the model represents the real vehicle. The full vehicle and also the driver were modeled through a CAD software, thus all geometries, mass and inertias were inputted in the multibody model based on the built vehicle. The vertical displacements were modeled in the multibody software simulating the road profile, so it was possible to analyze the vehicle ride behavior with different set ups in different tracks. The validation of multibody mathematical model was made by modeling the same maneuver that the vehicle instrumented with data acquisition was submitted. The mathematical model output and the data acquisition results were confronted and the results shows that the mathematical model can be considered validated. After the mathematical model be validated, it can be use in future analysis with high confidence level. This model will be helpful to evaluate design and make modifications in earlier phases of vehicle development, reducing cost, engineering time, prototype manufacturing and mainly time in test phase once that will be necessary just the fine tuning.
- Comparative Investigation into the Structural Braces Proposed at Baja SAE Competitions(2021-12-07) MUNIZ, B. P. L.; DE MELLO, L. T. R.; DA SILVA, G. R.© 2021 SAE International. All rights reserved.The BAJA SAE Brasil competition presents major technical challenges to its participants every year, including the design and manufacture of tubular frames according the Regulamento Administrativo e Técnico Baja SAE Brasil, RATBSB. The vehicle must have at least one of two possible bracing systems: front or rear, which differ in terms of the positioning of the main tubes for impact containment. The use of front braced frames is extremely widespread among Brazilian teams, due in part to the difficulty of designing rear braced frames, as they require more tubes and cause difficulties in accessing the engine compartment compared to the required structural configurations by international rules. The present study evaluates four structure configurations, these being the most comprehensive possible within the possibilities of the rules, defining loading scenarios coherent with possible accidents in competitions. There is the displacement of the structure and invasion of the survival cell, margin of safety of critical structural points through the Cozzone method, in addition to critical loads and linear buckling modes through their eigenvalues and eigenvectors, respectively. It was concluded that the requirements imposed by the Brazilian regulation, RATBSB, for rear bracing configurations do not bring outstanding additional security benefits in comparison to foreign configurations. A lower efficiency was also observed in relation to the safety of the 'nose' car configuration compared to the others.
- Life Cycle Assessment of Vehicular Electrification(2021-12-07) TOMAKI, E.; POLICARPO, E.; ROVAI, F.© 2021 SAE International. All rights reserved.Internal Combustion Engine vehicles (ICEV) have approximately 80% of their environmental impact during operation, 20% during manufacturing and disposal/recycling at the end of life. On the other hand, Battery Electric Vehicles (BEV) have a relatively lower impact during their use. However, BEVs produce proportionally higher equivalent-carbon dioxide (CO2e) emissions during vehicle manufacturing, which is adversely affected by the production of the battery. To account for the global environmental impact, a complete Life Cycle Assessment (LCA) needs to be done. In this work, data published by different sources and car manufacturers were used to predict the accumulated CO2e emissions along the vehicle life. In addition, a few scenarios with different assumptions were investigated. In particular, the impact of ICEVs and BEVs utilization in Brazil is lower than the world average due to the use of bioethanol as fuel and the low carbon intensity of the electricity. Most of the scenarios indicate that due to large environmental impact of the battery manufacturing, BEV CO2e emissions will break-even with the ICE vehicles only after several thousand km of usage. For some countries, the high carbon intensity of electricity will make the BEV a bad choice to mitigate climate change, as demonstrated by the higher life cycle CO2e emissions than those produced by ICEVs. For Brazil, the lower carbon intensity of the bioethanol combined with the existing fuel distribution infrastructure and the car plants indicate that moving from ICEV to BEV needs dedicated attention and may be attractive on high usage (taxi, shared cars etc.) which the higher initial CO2e impact, as well as cost, will be compensated along with car life).
- Test and Validation of Vehicle Vertical Dynamics in a Multibody Doftware(2015-09-22) AFONSO, B.; CHICUTA, W.; Roberto BortolussiCopyright © 2015 SAE International.This paper shows the elaboration of studies about the driver's comfort in a Baja SAE vehicle in different track conditions. The multibody model was designed in ADAMS VIEW software with full vehicle components aim evaluate frequencies, accelerations and displacements in any part of the vehicle. Several tests and measurements were made to acquire springs, dampers and tire data to ensure the model represents the real vehicle. The full vehicle and also the driver were modeled through a CAD software, thus all geometries, mass and inertias were inputted in the multibody model based on the built vehicle. The vertical displacements were modeled in the multibody software simulating the road profile, so it was possible to analyze the vehicle ride behavior with different set ups in different tracks. The validation of multibody mathematical model was made by modeling the same maneuver that the vehicle instrumented with data acquisition was submitted. The mathematical model output and the data acquisition results were confronted and the results shows that the mathematical model can be considered validated. After the mathematical model be validated, it can be use in future analysis with high confidence level. This model will be helpful to evaluate design and make modifications in earlier phases of vehicle development, reducing cost, engineering time, prototype manufacturing and mainly time in test phase once that will be necessary just the fine tuning.
- Heat Transfer Analysis in a Usual Ventilated Brake Disc(2015-05-13) CIOLFI, M. J.; Paulo de MelloCopyright © 2015 SAE International.This paper presents the different "gradients" of heat transfer coefficients found in a usual ventilated brake disc type. Although the conduction coefficient depends on the material characteristics applied, the convection and radiation coefficients changes as function of vehicle speed and brake temperature respectively. By comparing the coefficients magnitude orders of each surface and condition is possible to define the most favorable geometries for cool down the system.
- Study of Geometric Parameters for Validation and Reduction Effort in Steering System of a Vehicle FSAE(2015-09-22) TOGNOLLI, A.; SERAFIM, C. C. G.; GARCIA, B. A.Copyright © 2015 SAE International.This paper explores the method of modeling and validation the computational tools able to accurately replicate the dynamic behavior of a Formula SAE vehicle. Based on limitations in conducting physical tests, it is possible to mathematically predict the forces and momentum generated on the steering column of the vehicle, minimizing effort and improving driver comfort even before the component physically manufactured. The results in permanent state due technical instrumentations were used in the physical vehicles and compared with other proposals (skid Pad test). As the software simulating the same path, it was possible to adopt values of speed and wheel steering, allowing compare the dynamics of the vehicle, through the signals from other sensors installed in the data acquisition system, validating the behavior of the models presented in permanent state. Other aspects were studied to understand vehicle behavior concerning lateral stability and steering behavior. In order to improve the steering system, the axle sleeve was changed, resulting in driver's less effort on handling. This proposal was compared to virtual models noting the efficiency of multibody models and was observed the decrease in an effort to turn the steering wheel.
- Device for Measuring Efforts Generated by Tire in Steering Conditions(2018-09-03) CHICUTA, W.; AFONSO, B.; Roberto Bortolussi; Sergio Delijaicov© 2018 SAE International. All Rights Reserved.Currently, large companies as well as universities have increased the studies into vehicular dynamic behavior, mainly in order to improve driver and passenger safety. Simulations with complete model vehicle have been used for these studies. The tire is one of the most important vehicular component as the only connection with the ground and responsible for transmitting all vertical, longitudinal and lateral forces, consequenetly it is the main component on the model vehicle, being crucial for the correlation between computer simulations results and field tests, This paper presents a methodology, development and construction of a device to obtain lateral forces in any combination of toe and camber angles for different conditions of normal load, the tests can be performed on any type of ground, whether dry or wet. The tire datas used as reference were obtained through an experimental test using "Flat Trac" equipment. Based on these data, the components used to measuare the tire force, were developed. After the device construction, bench tests were performed in order to validate all project assumptions and calibrate the device. Finally, the device was installed on a small truck and a verification test were performed.