Optimization and Finite Element Analysis of Single Cylinder Engine Crankshaft for Improving Fatigue Life

摘要

Crankshaft is large volume production component with a complex geometry in internal combustion Engine (ICE), which converts the reciprocating displacement of the piston into a rotary motion of the crank. An effort was done in this paper to improve fatigue life for single cylinder engine crankshaft with geometric optimization. The modeling of the original and optimized crankshaft is created using SOLIDWORK Software and imported to ANSYS software for analysis. Finite element analysis (FEA) was performed to obtain maximum stress point or concentrated stress, to optimize the life of crank shaft by applying the boundary conditions. The maximum stress appears at the fillet areas between the crankshaft journal and crank web. The FE model of the crankshaft geometry is meshed with tetrahedral elements. Mesh refinement are done on the crank pin fillet and journal fillet, so that fine mesh is obtained on fillet areas, which are generally critical locations on crankshaft. The failure in the crankshaft initiated at the fillet region of the journal, and fatigue is the dominant mechanism of failure. Geometry optimization resulted in 15% stress reduction and life is optimized 62.55% crankshaft which was achieved by changing crankpin fillet radius and 25.88% stress reduction and life is optimized 70.63% of crankpin diameter change. Then the results Von-misses stress, shear stress and life of crankshaft is done using ANSYS software results. It was concluded from that the result of geometric optimization parameter; like changing crankpin fillet radius and crankpin diameter were changes in model of crankshaft to improve fatigue life of crankshaft.