A Simulation Method for Predicting Connecting Rod Buckling Stress and Fatigue Safety Factor of a Four-Cylinder Small Displacement Engine

Abstract

It is essential to predict the fatigue safety factor for connecting rod during the concept phase of an engine development as it is an important part to transmit combustion gas pressure to crankshaft. At present, it is still difficult to capture accurate stress results which could be further used for fatigue strength prediction during design phase. In this paper, a new method combining Finite Element Analysis (FEA) and Multi-body Dynamics (MBD) to calculate dynamic stress under assembly load case and dynamic firing load at each main key case is described. High cycle fatigue safety factor, connecting rod to cap contact performance, and buckling cover factor are also got through postprocessor. Experiment of the connecting rod is conducted to verify the results of the 3D structural simulation method. Well agreement is shown with simulation result of buckling cover factor and high cycle fatigue safety factor which proved this simulation method predicts connecting rod buckling cover factor and fatigue strength accurately. Also, the development period is shortened effectively.