Fatigue Optimization Design Method for Block of Aero Piston Engine

Abstract

Poor reliability of engine block is a technical problem in airworthiness certification of aviation piston engine. Taking the engine block of a certain type of engine as the research object, the transient load curve of the engine block is obtained and fitted through the model simulation, and it is restrained according to the actual installation. The Goodman method is used to analyze the high cycle fatigue of the engine block, the fatigue safety factor of block is obtained. A design method of separated main bearing cap is put forward to optimize the structure of the lower engine block, and the comparative analysis is carried out under the same load conditions. The Weibull mathematical model is used to verify the block reliability indexes, and the optimized block is performed with durability test. The results show that the fatigue safety factor, engine life and reliability of the lower block are improved, and the design method is of a certain reference value to improve the reliability of similar structures.

Keywords

• block
• transient load
• high cycle fatigue
• separated main bearing cap
• fatigue safety factor