Stress Analysis and Weight Reduction of a One-Cylinder Engine Crankshaft

Abstract

The paper deals with the weight reduction and the achievement of a more homogeneous stress distribution of a one-cylinder engine's crankshaft, developed for the Formula Student series. In order to achieve this goal, a series of static FEM analysis were performed on the crankshaft. For the FEM analyses, the critical loading and kinematic boundary conditions of the crankshaft were calculated with two different methods. The loads were determined analytically and were verified by Creo Mechanism software. The calculations were done for different engine speeds and-as a resultthe critical engine speed, where the highest loads appear could be determined. An essential weight reduction and a more homogeneous stress distribution were achieved on the crankshaft as the result of FEM analysis.

Dynamic Analysis of a One-cylinder Engine Crankshaft

“…The speed irregularity of the clutch of the original, as well as of the modified crankshaft [1] can be seen in Fig. 16.…”

“…As a kinematic boundary condition in static analysis, an elastic support was used on the contact surface of the main bearings [1]. At free vibration analysis kinematic boundary condition does not need to be defined.…”

“…14. shows the same quantity, but caused by the separate orders of the excitation forces. In order to be able to compare the results, the mean relative angular deflection of the original crankshaft [1] is also plotted in Fig. 13.…”

“…The investigation and clarification of the abovementioned points is crucial because of the constructional modifications [1]. Since the stiffness of the crankshaft has been reduced [1], the structure has become more sensitive to excitation loads, to vibration and to resonance phenomena.…”