Abstract: In order to make the life prediction of the crankshaft strength and fatigue life when the
maximum explosion pressure of a V diesel engine change from 15.5 MPa to 16.5 MPa. First we
establish the dynamics model of engine in the ADAMS/engine based on engine model and parameters,
and obtain the load time history data of the crank pin point, then we establish four cylinder ignition
conditions finite element model of the first cylinder and the second cylinder when the maximum
explosion pressure change from 15.5 MPa to 16.5 MPa. Then we calculate and get the each working
condition fatigue life of the crankshaft according to the stress of all working conditions, the material
s-n curve and the load time history curve. Calculation results show that the crankshaft maximum
stress is less than the material fatigue limit in various operating conditions, and the stress
concentration place mainly happens in the transition fillet of the connecting rod and journal, and the
crankshaft life is over 1 000 hours in various working conditions.

Key words: internal combustion engine, crankshaft, finite element method, strength, fatigue life