Topology Optimization of a Gearbox Housing for Structural Weight Reduction Using Finite Element Analysis
The gearbox housing in automotive transmissions plays a critical role in maintaining shaft alignment and supporting bearings and gears under operational loads, yet conventional designs frequently incorporate excess material that increases mass without enhancing performance. This study integrates transmission load analysis, finite element modeling, and topology optimization to derive an efficient material layout for a gearbox housing under realistic loading conditions obtained from a spur-gear transmission system. Loads were determined from detailed calculations of gear forces, shaft reactions, and bearing supports using specified vehicle parameters (maximum engine torque of 152 Nm, gross vehicle weight of 1850 kg). A finite-element model of the AA380 aluminum alloy housing was constructed with fixed boundary conditions at the clutch interface and bearing forces applied at the mounting locations. Topology optimization was then performed to minimize mass while constraining maximum von Mises stress and deformation. The optimized design achieved a 65% mass reduction. Post-optimization analysis confirmed that the peak stress remained below the material yield strength and that structural stiffness satisfied transmission requirements. These results demonstrate that topology optimization, when driven by transmission-derived loads, enables substantial lightweighting of gearbox housings without compromising functional integrity. The methodology offers a practical route toward more efficient drivetrain components.