Finite Element-Based Geometry Optimization to Enhance Fatigue Life of a Single-Cylinder Engine Crankshaft

Abstract

The crankshaft of an internal combustion engine (ICE) is a complex, high-volume manufacturing component responsible for converting the piston's reciprocating motion into rotational movement. This study explores how geometric modifications can enhance the fatigue life of a single-cylinder engine crankshaft. Both the original and optimized crankshaft models were created in SOLIDWORKS and then imported into ANSYS for examination. Boundary conditions were applied during finite element analysis (FEA) in ANSYS in order to determine the total fatigue life, maximum stress sites, and critical stress locations. Results indicate that the highest stress concentrations occur in the fillet sections between the crank web and crankshaft journal. The finite element model utilizes tetrahedral meshing, with refined meshing applied to the crank pin and journal fillets—regions that are particularly susceptible to failure. Fatigue analysis confirms that crankshaft failure typically initiates in the fillet region of the journal. By optimizing the crankshaft geometry—specifically, reducing the crankpin fillet radius and adjusting the crankpin diameter—stress was reduced by 15%, with a corresponding 62.55% increase in fatigue life. The ANSYS simulation results were used to determine Von Mises stress, shear stress, and overall crankshaft life. Ultimately, modifications to the crankpin fillet radius and diameter significantly improve the crankshaft’s durability, enhancing its fatigue resistance.

Cite as:

Deepanshu Yadav, & Vikash Dwivedi. (2025). Finite Element-Based Geometry Optimization to Enhance Fatigue Life of a Single-Cylinder Engine Crankshaft. Recent Innovations in Material Engineering, 1(2), 13–25. 

https://doi.org/10.5281/zenodo.16271682