Optimization of Connecting Rod on the basis of Static & Fatigue Analysis

ABSTRACT The 21st century competitive market demands light weight, low cost, fuel efficient engines, comfort drive with luxury at its best. Also with the ongoing restrictive emission norms and increasing fuel prices it’s been crucial to cut down the weight of engines. Hence manufacturers are adapting light weight engines to survive the cut throat competitive market. The various components of an engine are piston, crankshaft, connecting rod, valves etc. The connecting rod being an essential component in an engine it becomes crucial to optimize connecting rod. The connecting rods function is to transmit energy from piston to the crankshaft. The paper deals with the static and fatigue analysis of existing design of automotive connecting rod which is having mass of 11.46 kg. Theoretical fatigue factor of safety of this existing design is 2.3. The most critical area is cross oil hole at shank. But this design is having Fatigue life nearly equal to 1.393E007 cycles which is very high and can be considered as infinite life. So by studying the scope for material removal, we can modify this existing robust design to get sufficient life i.e. in the range of E006 cycles. The mass of modified design is 9.47 kg. Here we have optimized the I-section of existing design. It is obvious that, due to removal of material there is increase in the stress level at the critical zone. But increase in the stress level is such that, fatigue factor of safety of modified design is 1.8 and having fatigue life of 1.5E006 which satisfying general criteria of E006 cycles. So, modified design is offering sufficient life with 1.99 kg material saving (17.37% weight reduction) with respect to existing design