Investigation of the Stresses Induced in Crank Shaft AISI E4340 Forged Steel

Abstract

The Main objective of this study was to investigate the stresses induced in crank shaft manufactured of AISI E4340 forged steel. The Need of load history on FE Analysis necessitates performing a detailed dynamic load analysis. Therefore, this study consists of two major sections. First section is Kinematic and Dynamic analysis and second section is FE stress analysis. In this study an Experimental Test is initially conducted on Computerized Variable Compression Ratio at Compression ratio diesel engine testing machine of 16.5 for obtaining pressure vs. crank angle variation. The kinematic and dynamic analysis was done analytically by developing the equations of equilibrium from free body diagram of slider crank mechanism. The equations which are obtained through this analysis are used as input for determining the stresses. These forces were then applied along with boundary conditions on the model of crank shaft.. The stress analysis was performed at critical crank angles of rotation. The critical angles were determined by plotting the pin forces and bearing reactions with respect to the crank angles. These angles correspond to the positions where the axial and normal forces are maximum at either of the crank pin and bearings. The results in the form of Von-misses stresses and deformation were used to evaluate the factory of safety of crank shaft.