Experimental and numerical investigation of stress in engine crankshaft

Crankshaft is an important engine component that is working under high forces and stresses. Crankshaft loading consists of the moment inertia of the rotary mass, the moment inertia of the reciprocating mass and the combustion force that cause bending and torsional stresses in crankshaft. Bending and torsional stresses in crankshaft lead to fatigue loading. In this research, for a diesel engine, stresses in crankshaft were calculated by finite element method. And then, in order to validate these results, strain gauges were installed to measure strains and stresses. According to finite element results, the maximum value of the Von-Misses stress equaled to 580 MPa. In addition, the stress was about 8 MPa, where the strain gauge was installed. Data of the strain gauge measurement resulted in stresses less than 8 MPa. This result showed a good agreement with finite element model results. The maximum error between observed values and the finite element analysis was not more than 3.5%.