Numerical analysis and design optimization of vehicle suspension element

Cilj ovog rada je provoĊenje analize naprezanja i deformacije vilice osobnog automobila za razliĉite materijale, razliĉite geometrije, te topološkom optimizacijom poboljšati svojstva same vilice gledano iz aspekta praktiĉne primjene. U radu se nalazi šest poglavlja u kojima se objedinjuje tematika rada gledano sa praktiĉnog i teorijskog aspekta. Prvo poglavlje je uvodno, te se njime opisuje osnovna namjera i motivacija iza ovog diplomskog rada. U drugom poglavlju se nalaze rješenja automobilskih ovješenja kako bi se odabir modela lakše mogao staviti u perspektivu. Trećim poglavljem se dotiĉe teorijskih osnova metode konaĉnih elemenata. Time se pobliže teorijski opisuje metodika proraĉuna i analize korištene u ovom radu. Ĉetvrto poglavlje opisuje ĉetiri teorije ĉvrstoće, a naglasak je stavljen na ĉetvrtoj jer je ona mjerodavna kao pokazatelj uspješnosti analize u ovom radu. Ovim teorijama se pokušava predvidjeti granica teĉenja, odnosno granica prije pojave trajnih deformacija. Peto poglavlje opisuje postupak kojim se odvijala priprema i provoĊenje numeriĉke analize. Tu su opisani korišteni modeli, postavke numeriĉke mreže te opterećenja i oslonaca kao i materijal koji se pridružuje modelu. Nakon prve analize, napravljena su geometrijska poboljšanja i dobiveni su rezultati koji su pokazali da je takva geometrija uistinu bolja od prethodne. Za usporedbu je prikazana i numeriĉka analiza trkaće vilice. Nakon toga se promatralo promjene prilikom promjene korištenih materijala te se provela topološka optimizacija vilice. Topološka optimizacija je pokazala gdje postoji višak materijala te se kao takav uklonio i ponovno se pokrenula analiza kako bi se pokazalo da je optimizacija uspješna i toĉna. Šestim poglavljem zakljuĉuje se tema i rezultati ovog rada.The aim of this paper is to analzye stress and strain characteristics of lower control arm in a personal vehicle for different materials, different geometries, and with topological optimization to better the properties of lower control arm in regards to practical use. The paper is divided into six chapters where we consolidate the theme of this paper from both practical and theoretical aspects. First chapter is introductory, and it describes the basic intent and motivation behind this paper. The second chapter explains basics of car suspension so that it is easier to put everything into perspective. Third chapter deals with theoretical fundamentals of finite element method. That way we get theoretical background of the calculation and analysis used in this paper. Fourth chapter describes four failure theories and a bit more emphasis was given to the fourth one because it is a method that is used as a pointer of successful improvement of lower control arm. With these theories we try to predict yield point, or in other words, occurence of plastic deformations. Fifth chapter describes the process of preparing for numerical analysis and analysis itself. Here we can find models used, settings for the mesh, loads, supports and material that was assigned to the model. After the first analysis, improvements to design of the control arm were made and results showed that that improved control arm was indeed better than the previous one. For comparison a numerical analysis of racing lower control arm was made. After that, properties with different materials were checked and then topological optimization of control arm was made. Topological optimization showed where the surpluss of material was located and so it was removed from those places and numerical analysis was restarted to show that optimization of control arm was successful and correct. Sixth chapter concludes the theme of this paper