Design and Optimization of Crankshaft for Four Cylinder 4-Stroke Spark Ignition Engine using Transient Structural Analysis

The objective of this article is to propose an optimized design structure of the crankshaft for a four-cylinder four stroke spark ignition engine. The new design is compared to the existing one on different grounds of performance characteristics for engines with varied purposes. A three-dimensional crankshaft was created through reverse engineering techniques, on SOLIDWORKS and then imported to ANSYS for a transient structural analysis. The variable time varying force was derived from the pressure-crank angle graph of the CBR600 engine and used ultimately for this analysis. Three new materials were tested on the crankshaft – 4130 chromoly steel, Titanium alloy Ti6Al-4V, Epoxy Carbon fibre (230 GPa- Woven). The focus is on the new light weight design of the crankshaft incorporating the usage of the abovementioned materials and through transient structural analysis, the feasibility is studied. The reduced weight of the crankshaft was 7.6 Kg and 12.9 percent less compared to the existing crankshaft without compromising the strength to weight ratio.