Current tractor market demands light weight components to meet the need of cost-effective tractor with higher fuel efficiency. Skid assembly is one of the heaviest subsystems of a tractor subjected to the loads from the external implements, ground, engine and internal loads due to transmission line. It consists of several casting components with many geometric features such as flanges, bosses etc. These geometric features are very essential in terms of assembly, manufacturing & packaging considerations. Effective material distribution for tractor parts play a significant role in reducing the overall weight of the tractor. OEMS are moving from conventional grey cast iron housing to aluminum, which is not only the light weighting solution but also provides strength, stiffness, and resistance to corrosion. Aluminum die casting wall thickness is key for die casting part as the thickness increase strength decreases and also cause void, pits, porosity problems. With air pockets and rib patterns, we can make housings much lighter with minimal wall thickness without sacrificing structural integrity. Conventional methods like topology optimization needs good interpretation skills and usually take many iterations to finally converge. In this paper, a new innovative approach of combining various optimization techniques, an integrated optimization methodology, has been proposed to achieve quick design convergence. In the current work, Initially, a solid topology optimization at the substructure level has been performed to quickly identify sensitive regions of the structure that have the most impact on the performance. Using these sensitive regions, a design space is generated with shell elements in the form of ribs. A topology optimization is conducted again to identify the critical regions of the ribs, and subsequently sizing optimization is used to determine the optimum thicknesses of the ribs. The final suggested optimized rib pattern has given improved performance compared to baseline design. A substructure methodology also has been proposed to reduce the optimization run time in this paper.

Mrs. Theja Bollu, Mahindra&Mahindra, INDIA Mr. Sairam Peddi, Mahindra & Mahindra, INDIA