Analysis of dynamic fatigue characteristics of critical parts of highly strengthened single cylinder diesel engine

Abstract

In this paper, the strength analysis and fatigue life calculation of multi-component coupling of crankshaft, connecting rod and engine body of highly strengthened single cylinder diesel engine are carried out. The stress of crankshaft, connecting rod and engine body in two working cycles is calculated by multi-component coupling transient dynamics, and the strength is analyzed based on the third strength theory firstly; Then, the accuracy of the transient calculation results is verified by the strength experiment of the crankshaft and connecting rod reduced scale model and the calculation of the static stress of the body; Finally, according to the stress fatigue life calculation method, the fatigue life of crankshaft, connecting rod and engine body is calculated. The maximum stress of crankshaft, connecting rod and body is less than the yield limit of corresponding materials; The fatigue life calculation results show that the damage accumulation of the engine body is very little, which meets the design requirements of infinite life. The damage accumulation of the crankshaft at the fillet of the main journal and the connecting rod at the side of the rod is 32005.6 hours and 102841.7 hours respectively, which meeting the design requirements of 20000 hours.