Dynamic simulation and stress analysis for reciprocating compressor crankshaft

With the continuous trend toward high speed and large size, the reciprocating compressor crankshaft faces more serious potential threat of crack due to vibration. Therefore, early stress analysis of the crankshaft must be done thoroughly in the design stage. This article introduces a method, which combines flexible body dynamic and finite element analysis to calculate stress of the crankshaft. In this method, the load variation with time is obtained by flexible body dynamics simulation of crank and connecting rod mechanism. After that loads are loaded on finite element model of the crankshaft, and then the stress of the crankshaft is calculated in time domain. This stress can be utilized to do fatigue analysis and predict the life of crankshaft. Using this method, stress of a practical crankshaft, belonging to 6M51 reciprocating compressor, is calculated. The result showed that the maximum von Mises stress is 158 MPa, and the estimated life, which was calculated by Palmgren–Miner linear damage accumulation theory, is 2.0230e + 007 hours.