Karakterizacija ogljikovih vlaken in izdelava platišč za električni dirkalnik Formule Student

Gudžulić, Tara (avtor), Fajfar, Peter (mentor), Žužek, Borut (komentor)

Superior Engineering je ekipa mladih bodočih inženirjev in inženirk različnih fakultet Univerze v Ljubljani. Trenutno ekipo sestavlja 70 aktivnih članov, ki tekom študijskega leta izdeluje električni dirkalnik po zgledu Formule 1, s katerim sodelujemo na tekmovanju Formule Student. V sezoni 2023/24 smo se ob izdelavi novega električnega dirkalnika osredotočili na odpravo glavnih težav dirkalnika, ki smo jih imeli v prejšnji sezoni. Ena od večjih težav je bilo tesnjenje naših samostojno izdelanih platišč iz ogljikovih vlaken, ki jih nismo mogli voziti pod tlakom manj kot 1,50 bar in nenadzorovanem snemanju pnevmatik med vožnjo. V primerjavi z lansko sezono smo spremenili dimenzije aluminijastega kalupa, s čimer sta se spremenili tudi širina in premer platišča. Končne dimenzije so bile dosežene s postopkom struženja. V letošnji sezoni smo izboljšali proizvodni proces tudi z drugačnim pristopom v načinu utrjevanja materiala. Za izdelavo platišč iz ogljikovih vlaken smo uporabili kompozitni material MTC510 C200 42 % RW, MTC510 C245T 42 % RW in VTC401 CBX214 ± 45 - 42 % RW. Spremenili smo načrt laminata, poudarek je bil predvsem na debelini robov, ki smo ga precej povečali. Sprememba metode utrjevanja iz utrjevanja materiala v navadni pečici na utrjevanje v avtoklavu, je pomenila veliko razliko v končnih mehanskih lastnostih in tudi v končnem izgledu. Teža celotnega platišča je bila med 900 g in 1000 g (takoj po razkalupljenju), končna teža, ko je bilo platišče v celoti pripravljeno za montažo na pnevmatiko, pa se je gibala med 1050 g in 1200 g (s sredino, vijaki, maticami in po struženju, itd.). Platišča so bila v celoti izdelana iz prepreg materiala iz ogljikovih vlaken s središčnim delom iz aluminijeve zlitine Al7075 T6. Za boljše razumevanje lastnosti uporabljenega materiala smo izvedli še karakterizacijo materiala, ki smo ga dobili iz nateznih, upogibnih in strižnih preizkusov. Meritve smo izvedli na kompozitnem materialu MTC510 C245T 42 % RW in VTC401 CBX214 ± 45 - 42 % RW, ki imata različno polimerno matico, drugačno število ogljikovih vlaken v eni tkanini in drugačen način vezave. Preizkušance smo pripravili po standardih EN ISO 527-4, EN ISO 14125 in EN ISO 14130. Zanimale so nas predvsem razlike med različnima vrstama kompozitnega materiala in razlike med orientacijami ± 45° in 0/90°.

• Jezik: Slovenski jezik
• Ključne besede: Električni dirkalnik, Formula Student, platišče, ogljikova vlakna, karakterizacija ogljikovih vlaken, kompozitni materiali.
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: NTF - Naravoslovnotehniška fakulteta
• Leto izida: 2024
• PID: 20.500.12556/RUL-162687
• Datum objave v RUL: 26.09.2024

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Characterisation of carbon fibers and production of rims for the Formula Student electric racing car

Izvleček

Superior Engineering is a team of young future engineers from various faculties of the University of Ljubljana. Currently, the team consists of 70 active members, who during the academic year build an electric racing car modeled after Formula 1, with which we participate in the Formula Student competition. In the 2023/24 season, when building a new electric racing car, we focused on eliminating the main problems of the racing car that we had in the previous season. One of the major problems was the sealing of our self-made carbon fiber rims, which we could not run under 1.50 bar pressure and uncontrolled tire deflation while driving. Compared to last season, we changed the dimensions of the aluminum mold, which also changed the width and diameter of the rim. The final dimensions were achieved by a turning process. This season, we improved the production process with a different approach in the way of hardening the material. The composite material MTC510 C200 42% RW, MTC510 C245T 42% RW and VTC401 CBX214 ± 45 - 42% RW were used to make the carbon fiber rims. We changed the plan of the laminate, the emphasis was mainly on the thickness of the edges, which we increased considerably. Changing the curing method from curing the material in an ordinary oven to curing in an autoclave meant a big difference in the final mechanical properties and also in the final appearance. The weight of the entire rim was between 900 g and 1000 g (immediately after demoulding), and the final weight when the rim was fully prepared for mounting on the tire was between 1050 g and 1200 g (with the center, bolts, nuts and after turning, etc.). The rims were made entirely of prepreg carbon fiber material with a center section of Al7075 T6 aluminum alloy. In order to better understand the properties of the material used, we also performed a characterisation of the material obtained from tensile, bending and shear tests. The measurements were performed on the composite material MTC510 C245T 42% RW and VTC401 CBX214 ± 45 - 42% RW, which have a different polymer matrix, a different number of carbon fibers in one fabric and a different bonding method. We prepared the test pieces according to EN ISO 527-4, EN ISO 14125 and EN ISO 14130 standards. We were mainly interested in the differences between different types of composite material and the differences between ± 45° and 0/90° orientations.

• Ključne besede: Electric racing car, Formula Student, rim, carbon fiber, carbon fiber characterisation, composite materials.