Geometry Modification of a Two Wheeler Crankshaft for the Mass Reduction

Abstract

The crankshaft is an important component of internal combustion engine having complex geometry that
converts linear reciprocating displacement of the piston into rotary motion. The main objective of this work is mass
reduction of forged crankshaft used in single cylinder four stroke engine of two wheeler vehicle. This study consists of
two major sections, Finite Element Analysis and design modification for mass reduction of a crankshaft. Design
modification of the crankshaft can be done by considering the type, location and peak value of stresses. Crank web
thickness and crankpin diameter are the suggested design modification parameters in current work to reduce the mass of
the crankshaft. The main work is to model the crankshaft with dimensions and then simulate the crankshaft for static
structural and fatigue analysis. Three dimensional model of the crankshaft is developed in CATIA v5 and imported to
HYPERMESH v11.0 for strength analysis. Strength analysis of crankshaft is done for maximum loading condition.
Simulation inputs are taken from engine specification chart. The load is applied to the finite element model of crankshaft
in HYPERMESH and boundary conditions were applied according to engine mounting conditions. The fatigue life of the
crankshaft is predicted by using FEMFAT 5.0 Fatigue software.