An Evaluation of Crankshaft Bending Rigidity Using Finite Element Analysis 2013-01-0126
In the current scenario of automotive industries, designers are focusing on the development of lightweight, compact and high pressure engines. This demands downsizing of the engine components without compromising its strength. Crankshaft design is crucial in deciding the engine efficiency along with higher strength to weight ratio. Hence, the precise knowledge on crankshaft bending and torsion rigidity is required at design stage. This greatly influences on life performance of crankshaft, engine block and bearing.
The study aims at a) Evaluation of crankshaft bending rigidity by Finite Element Analysis (FEA) and its experimental validation, b) Study the effect of crankshaft orientation on bending rigidity and c) Evaluate most critical geometric parameters of the crankshaft (Crankpin and Journal diameter, Pin and Journal width, Throw, Web thickness and Web width) and their quantitative contribution to bending rigidity.
For six cylinder automotive crankshafts, bending rigidity is evaluated by both FEA and experimental method. Bending rigidity values evaluated by FEA correlates very well with those calculated by experimental methods. This study has shown that, six cylinder crankshaft is having highest rigidity when pin 1 and 6 are on top and lowest rigidity when pin 3 and 4 are on top. From this study major critical geometric parameters and their quantitative contribution to bending rigidity is evaluated. Pin diameter and journal diameter are major positive contributors while throw is major negative contributor to crankshaft bending rigidity.