Fatigue test and numerical simulation on connecting rod in high power diesel engine

The fatigue strength testes are done on the connecting rods of a high power diesel engine to observe the microscopic topography of the fractures,and the main influencing factors that lead to the fracture of connecting rod are analyzed.The test results show that the fatigue cracks that caused by the residual compressive stress of connecting rod are usually conceived at the subsurface,and the small end of connecting rod is more sensitive to the mixed defect of the surface because of its high level of average stress.The numerical simulation of fatigue durability test on connecting rod is done using 3D finite element numerical calculation method and fatigue life prediction theory.The comparison between fatigue test and virtual fatigue life prediction results for connecting rod shows that,to a certain extent,the fatigue life prediction method based on the S-N curve of the material can simulate and predict the weak part and fatigue life,where the connecting rod is destroyed in the fatigue test.