[en] Summary (English): Formula 1 is the pick of automobilism, and Formula Student, the principal students' motorsport competition. The first one is rigidly ruled by the International Automobilism Federation, while the second one allows the development of innovative solutions with almost no restrictions. For this reason, in this thesis it is presented the path for the design of a suspension focussed on a students' competition, based on the designs used in current Formula 1. But before arriving to a certain geometry and elements, this thesis starts studying all the common and competition suspension typologies, with the aim of understanding the development of these systems in a better way and its evolution along the time until arriving to the current situation. After this previous analysis, it is decided that the double wishbone suspension is the most suitable one for a single seater, thanks to all the possibilities that it offers referring to modifications. And it will use the same configuration as a Formula 1, excepting some modifications which are consequence of the difference between both type of vehicle. Hereunder, some of the main features of the single seater for which this system has been designed are shown: • Suspension travel in bound and rebound: 25.4 mm (specified in Formula Student's rules) • Roll angle: 1.5°, typical value for this type of single seaters • Steering travel: 25 mm, typical value for this type of single seaters • Wheelbase: 1530 mm, low value, as circuits have short straights and closed corners • Track: 1220 mm, high value to reduce centre of gravity's height • Mass: sprung 170 kg, driver 70 kg, unsprung 40 kg, aerodynamic load 60 kg • Height of centres of gravity: 270 mm in sprung mass, recommended value for these type of vehicles, and 264.8 mm for the whole mass • Tyre size: 10 inches • Weight balance: 42.95 % in the front axis, adjustable with setups • Brake balance: 60 % in the front axis, 80 % for the brake test, adjustable with setups Once the vehicle's features have been set, based on real data and rules, the scope of the project is studied, where all the tubes that include the suspension will be designed, including the tie rod, push rod, whole wishbones and rocker (all the elements with S355 steel, due to its high strength). Apart from that, it will be chosen the most suitable damper for the vehicle, and all the data needed for the manufacturing of a torsion spring (used as an elastic element) will be calculated. Therefore, the links between all the elements will not be designed (bolted and welded connections). After setting all the initial conditions, a kinematic analysis is run by using Lotus Suspension Analysis software, where the geometry of the suspension is obtained based on the handling of the vehicle that is wanted to be achieved. Once adequate results have been obtained, with all the parameters inside the stablished boundaries, emphasising the changes in camber and toe angles (with low variations), and roll centre's height (always above the ground), this stage is concluded and it can be started with the following one, the dynamic analysis. The next analysis consists on running different simulations based on real situations that the vehicle will have to face, with the aim of obtaining the reactions that will suffer each element and dimension them. For this purpose, the Adams Car software will be used, as it is specialized on vehicle's simulations and can recreate all the single seater's and surroundings features with great accuracy. But, as this project lacks of the data of a whole real car, a model provided by the company in charge of the development of the software, MSC Software, is used, adapting it to the design features that have been mentioned. This model shows some limitations that have affected to some elements from the design, like the need of producing a torsion spring that can deal with big deformations. Even tough, the results obtained are correct and have been obtained by running the following simulations: • Brake test with a brake balance of an 80 % in the front axis • Constant radius turning • Simulation of different types of braking around a real Formula Student circuit, with the aim of studying the behaviour of the suspension against fatigue Once all the forces have been calculated, all the elements mentioned in the scope are designed, using the finite element method in Ansys Workbench (and manual calculus when possible), by increasing loads with a safety factor of 1.2 and reducing the material's fatigue limit with modifying coefficients. The results achieved are as follows: • Lower wishbone: tube with an outer diameter of 10 mm and a thickness of 1 mm, with low range for optimization • Upper wishbone: tube with an outer diameter of 12 mm and a thickness of 1 mm, also optimized • Tie rod and push rod: they use the same tube as the lower wishbone, to seize material, and have a great safety factor • Rocker and rocker-axis: the rocker has been designed with a big central hole (which could still be optimized in some zones), while the rocker-axis has been designed with a specific safety factor, since the features of the link with the torsion spring cannot be determined • Torsion spring: all the data needed for its manufacturing is calculated, based on the twist that will support Finally, the possible next updates of the suspension are presented, among the ones spotlight seizing completely all the possibilities that Adams Car offers (with more real-situation-based simulations) and the future replacement of the material of some of the elements, changing S355 steel with carbon fibre, apart from calculating all the welding, links and accomplishing all the tests needed to end with the validation of the system.

[eu] Laburpena (euskara): 1 Formula automobilismoaren gunea da, eta Formula Student, ikasle auto lehiaketa nagusia. Lehengoa Automobilismo Internazionalaren Federazioa eraentzen du, eta bitartean, bigarrena ia murrizketa gabeko soluzio berritzaileen garapena baimentzen du. Arrazoi honengatik, proiektu honetan ikasle-lehiaketa batentzako esekiduraren diseinurako bidea aurkezten da, gaur egungo 1 Formulan erabilitako diseinuetan oinarrituta. Baina geometria mota eta elementu zehatz batzuetara ailegatu baino lehen, konpetizio eta ohiko esekidura tipologia guztiak aztertzen hasten da, sistema auhen garapena eta eboluzioa denboran zehar gaur egungo egoerara iritsi arte hobeto ulertzeko mugarekin. Aurretiko azterketa honen ondoren, trapezio bikoitzeko esekidura monoplaza batentzako hobeto moldatzen dena erabakitzen da, aldaketen alde eskaintzen dituen posibilitateei esker. Eta 1 Formula baten konfigurazioa erabiliko du, bi monoplaza moten ezaugarrien desberdintasunen ondorio diren aldaketa batzuk izan ezik. Jarraian, sistema hau erabiliko duen monoplazaren ezaugarri nagusiak azaltzen dira: • Esekiduraren ibiltartea botean eta re-botean: 25,4 mm (Formula Student-en arauetan zehaztuta) • Roll Angle (monoplazaren kulunka angelua): 1,5°, monoplaza hauentzako ohiko balioa • Direkzioaren ibiltartea: 25 mm, monoplaza hauentzako ohiko balioa • Bataila: 1530 mm, balio txikia, zirkuitoak zuzen motzak eta kurba itxiak dituztelako • Bidea: 1220 mm, balio handia grabitate zentroaren garaiera murrizteko • Masak: esekituta 170 kg, gidaria 70 kg, ez-esekituta 40 kg, karga aerodinamikoa 60 kg • Grabitate zentroen garaiera: 270 mm masa ez-esekituan, monoplaza hauentzako gomendaturiko balioa, eta 264,8 mm masa osoan • Pneumatikoen tamaina: 10 pulgada • Banaketak: pisua, 42,95 % aurretiko ardatzean; balaztatzea, 60 % aurretiko ardatzean eta 80 % aurretiko ardatzean balaztatze test-arako. Bi parametroak aldatu daitezke doikuntzen bidez Monoplazaren ezaugarriak benetako arau eta datuetan oinarrituz, proiektuaren norainokoa aztertzen da: esekiduraren tubo guztiak diseinatu dira, hau da, push rod-a, tie rod-a, trapezioak eta rocker-a (pieza guztiak altzairu S355 erabiliz, bere erresistentzia handiari esker). Gainera, motelgailu hoberena ere hautatuko da, eta elementu elastiko bezala erabiliko den tortsio malguki bat fabrikatzeko behar diren datuak kalkulatuko dira. Orduan, ez dira elementuen bitarteko loturak diseinatuko (soldadurak eta torlojugintza). Behin aurretiko baldintza guztiak finkatuta, analisi zinematiko bat egiten da Lotus Suspension Analysis software-arekin, ibilgailuaren bilaturiko jokaeran oinarrituta esekiduraren geometria lortzeko. Emaitza egokiak lortu ondoren, parametro guztiak ezarritako limiteen artean (gurpilen eraso eta erori angeluak bariazio txikiekin eta monoplazaren kulunka zentroa beti lurraren gainean), etapa hau bukatutzat ematen da eta hurrengoa planteatzen da, analisi dinamikoa. Ondorengo analisian egiazko egoerak simulatzen dira esekiduraren elementuen erreakzioak lortzeko eta haietan oinarrituta elementu bakoitza diseinatzeko. Arrazoi honengatik, etapa honetan Adams Car software-a erabiliko da, ibilgailuen simulazioetan espezializatuta, eta kotxearen ezaugarri guztiak eta ingurua zehaztasun handiarekin erreplikatzeko gai baita. Baina, monoplaza guzti baten datuak ez daudenez, ondorioz, MSC Software enpresak (Adams Car-en garatzailea) errazturiko modelo bat erabiltzen da, ezaugarrik batzuk aldatuz diseinutako kotxearen sistemari moldatzeko. Hala ere, modelo hau diseinuaren elementu batzuei eragin dioten eragozpen batzuk dauzka, adibidez, deformazio handiak baimentzen dituen tortsio malguki bat fabrikatzeko beharra. Dena den, emaitzak positiboak izan dira eta ondorengo simulazioetan oinarrituta lortu dira: • Balaztatze testa aurretiko ardatzean 80 % balaztatze banaketarekin • Erradio konstanteko biraketa • Balaztatze ezberdin batzuen simulazioa, Formula Student-ko egiazko zirkuitu baten aldera, esekiduraren neke portaera aztertzeko Esfortzu guztiak lortu ondoren, norainoan adierazitako elementu guztiak diseinatzen dira, elementu finituen metodoarekin Ansys Workbench-n (eta eskuko kalkuluekin, ahal denean) kargak 1,2-ko segurtasun koefiziente batekin handituz eta materialaren neke limitearen balioa koefiziente aldatzaileen bidez txikituz. Segidan, lortutako emaitzak aurkezten dira: • Beheko trapezioa: 10 mm-ko kanpoko diametroarekin eta 1 mm-ko lodierarekin, optimizaziorako alde txikiarekin • Goiko trapezioa: 12 mm-ko kanpoko diametroarekin eta 1 mm-ko lodierarekin, optimizaziorako alde txikiarekin • Tie rod-a eta push rod-a: beheko trapezioko tubo berdina erabiltzen dute, materiala aprobetxatzeko, eta optimizaziorako alde handia dute • Rocker eta rocker-aren ardatza: alde batetik, rocker-a erdian hustuketa handi batekin diseinatu da (eta gune batzuetan optimizatu daiteke). Bestetik, ardatza segurtasun alde handi batekin diseinatu da, tortsio malgukiarekin daukan loturaren ezaugarriak ezin direlako zehaztu • Tortsio malgukia: fabrikatzeko behar diren datu guztiak kalkulatzen dira, jasango duen biraketan oinarrituz Amaitzeko, sistema hobetzeko eman ahal diren pausuak aurkezten dira, eta haien artean hurrengoak nabarmentzen dira: Adams Car-en posibilitate guztiak aprobetxatu (egiazko kondizioetan oinarritutako simulazio gehiagoekin), elementu batzuen materiala aldatzea (karbono-zuntza altzairuaren ordez), soldadura eta lotura guztiak kalkulatzea eta sistemaren balidazioarekin amaitzeko behar diren saiakuntza guztiak egitea.