| Abstract | Formula student, najprestižnije je studentsko inženjersko natjecanje u svijetu. Mnogi timovi, koji dolaze sa različitih sveučilišta, pomoću svojih znanja i vještina natječu se bolidima, konstruiranima prema pravilniku Formule Student, koje su samostalno razvili i proizveli. S obzirom da tehnologije pogona, ovjesa i aero paketa postaju sve kompleksnije i preciznije u čemu ih prati i značajno poboljšanje performansi, gume moraju zadovoljiti zahtjeve prenošenja sila nastalih od strane tih sustava.
Guma ili pneumatik, jedini je kontakt vozila s površinom po kojoj vozi. Kako je cilj pneumatika što bolje prenijeti sile na podlogu, važno je saznati bitne parametre kako bi se odabrao prikladan model, koji će zadovoljavati potrebe vozila. Kako bi se mogao odabrati prikladan model gume, potrebno je saznati različita svojstva koja utječu na performanse pneumatika, a samim time i pneumatik na bolid u cijelosti. Problemi nastaju prilikom provođenja proračuna, a to su mogućnost ispitivanja malog broja različitih vrsta pneumatika i njihovih smjesa, što značajno reducira izbor pneumatika. Također jedan od problema prilikom provođenja proračuna dolazi zbog nepotpunosti podataka, iz razloga što su mjerenja provedena za uži raspon veličina nego što je potrebno. Uz navedena dva problema, bitno je razmišljati i o uspješnosti projekta u cijelosti, te ostvarenja njegova cilja, što je dostavljanje proizvedenog bolida na natjecanje u skladu sa zadanim rokovima. Na rokove uvelike utječe kašnjenje podataka potrebnih za postavljanja simulacija, koje su krucijalni element u razvoju bolida. S pretpostavkom da je definiranje svojstava kao što su otpori gume, longitudinalna i lateralna sila, koji ovise o parametrima kao što su kut klizanja, vertikalni kut nagiba, temperatura, brzina, pritisak u gumi i slično. Da bi bilo moguće definirati svojstva gume ovisno o prethodno navedenim parametrima, potrebno je osmisliti napravu koja će svojom konstrukcijom i rješenjima omogućavati mijenjanje ulaznih parametara koji se apliciraju na ispitni uzorak, čime će rezultat biti dobiveni podaci modela gume. Važno je naglasiti kako je cilj konstruirati napravu koja će se koristiti u svrhu dobivanja podataka, koje će koristiti FSB Racing Team u razvoju vlastitog bolida, te je samim time naprava konstruirana prema tim zahtjevima. Odnosno, konstrukcijska rješenja, dimenzije i odabrani materijali prilagođeni su zahtjevima potrebnim kako bi se mogli ispitati pneumatici namijenjeni za formula student bolide. Da bi razvoj ovakve naprave bio moguć i potpun, potrebno je definirati listu zahtjeva i projektne parametre stroja za ispitivanje pneumatika. Nakon definiranih zahtjeva predložena su tri koncepta po završetku čije evaluacije je odabran najprikladniji koncept. Najprikladniji koncept je potom konstrukcijski razrađen. Započevši od skica, koje su temelj prenošenja ideja tehničkih rješenja, provedeni su proračuni i analize kako bi se dokazala mogućnost izvedbe tog koncepta, prema čemu je izveden detaljan 3D model stroja, koji je popraćen tehničkom dokumentacijom.
Cilj ovog projekta je omogućiti FSB Racing Teamu dostavljanje bitnih podataka i svojstava modela pneumatika, što će uvelike unaprijediti i ubrzati razvoj bolida te ponuditi mogućnost ostvarivanja boljeg rezultata na natjecanjima Formule Student. |
| Abstract (english) | Formula Student is the most prestigious student engineering competition in the world. Many teams, coming from different universities, use their knowledge and skills to compete with cars designed according to Formula Student regulations, which they independently developed and produced. Considering that drivetrain, suspension, and aero package technologies are becoming more and more complex and precise, accompanied by a significant improvement in performance, tires must meet demands of transmitting forces created by these systems.
Tire is the vehicle’s only contact with the surface it is driving on. Since the goal of a tire is to transfer forces to the ground as much good as possible, it is important to find out the essential parameters to choose a suitable model that will meet needs of the vehicle. In order to choose the most adequate tire model it is necessary to find out various properties that impact on tire performance and also the impact of the tire on the whole car. Problems can be noticed during the calculations e.g. the possibility of testing a small number of different types of tires and their compounds that significantly reduces the choice of tires. Also, one of the problems during calculations comes from incomplete data because due to the fact that measurements were carried out for a narrowed range of measurements than necessary. Considering these two problems, it is also important to think about the success of the project, and the achievement of its goal which is to deliver the manufactured car to the competition in accordance with the given deadlines. Deadlines can be affected by the delay of the data needed for simulations that are crucial element for the development of the car. Defining properties such as tire resistance, longitudinal and lateral force, that depend on parameters such as slip angle, vertical angle of inclination, temperature, speed, tire pressure etc. are really important data needed for these kind of calculations. In order to be able to define the properties of the tire depending on the previously mentioned parameters it is necessary to develop a device that will with its construction and solutions allow changing the input parameters that will be applied to the test sample, which will result in the data of the tire model. It is important to emphasize that the main goal is to design a device that will be used for the purpose of obtaining data, that will be used by FSB Racing Team in the development of their car. Therefore, the device will be designed according to its requirements. That means that the design solutions, dimensions and selected materials will be adapted to the needed requirements in order to be able to test the tires intended for the formula student cars. For the successful development of such a device it is necessary to define the list of requirements and project parameters of the tire testing machine. After defining those parameters three concepts were proposed upon completion of the evaluation of which the most appropriate concept was selected. The most suitable concept was then developed in detail. Starting from sketches, that are the ground of transferring technical solutions, the calculations and analyses were carried out in order to prove the feasibility of the concept. According to that, followed by a technical documentation, the 3D model of the device was created.
The aim of this project is to enable FSB Racing Team to provide essential data and properties of specific tire models that will improve and speed up the development of the car, but also offer the possibility of achieving better result on Formula Student competitions. |
