Application of Topology Optimization to Reduce Automotive Exhaust Emissions

In automotive, the use of heavy structure leads to high consumptions of fuel and resulting high exhaust (CO₂) emissions. To curb this problem, nowadays, the conventional steel used for years in automotive structures is being replaced with other different lightweight materials such as aluminum, magnesium, glass fiber-reinforced polymer, carbon fiber-reinforced polymer, titanium, and so on. On the other hand, compared to the known steel properties and performances, these lightweight materials offer challenging issues related to life cycle, recycling, cost, and manufacturing. But, more than sometimes, reaching the same levels of performances with materials different from steel present huge difficulties. This represents the cause of researching strategies and techniques to optimize the material distribution and the performances of a component, saving material and consequently reducing weight. This article reports a procedure oriented to a smart distribution of material (conventional steel) in the automotive structure by employing topology optimization (TO) in the early concept design stage to produce a lightweight structure. In this research work, student formula car frame is taken as a case study and its novel design is presented as a sheet metal structure rather than a pipe structure. This case study is analyzed in accordance with 2017/2018 Formula SAE Rules, which implies multiple load cases for testing and validation of the student formula car frame design. OptiStruct solver is used for the numerical simulation of density-based TO (following SIMP approach and linear static analysis). After the numerical analysis, it is concluded that the mass of the student formula car frame and CO₂ emissions are successfully reduced by 68.42% and 5.98 g/km, respectively.