Optimization of aerospace engine bolt tightening based on Kriging model

Abstract

Bolt tightening is widely used in various types of aerospace engine assembly process. To ensure the tightness of the aerospace engine, it is extremely important to reduce the deformation of the engine and achieve uniform bolt preload in the tightening process. The initial clearance value between nozzle and chamber of different types of aerospace engine is different, which makes the tightening target of low deformation and even load difficult. Besides, the impact of elastic interaction makes the tightening of aerospace engine very challenging. And aerospace engine bolt tightening is too time-consuming. A method is proposed in this paper to solve the above puzzle. The influence of elastic interaction in the tightening process can be weakened by optimizing the tightening sequence, and the optimal tightening process of different types of aerospace engines under different clearance values can be predicted based on kriging model. The experiment shows that the deformation of the engine deduce by 82% and 72%, the average preload deduce by 3.8% and 5.1%. Then kriging model is used to predict the best tightening sequence under different types and tightening clearance. The genetic algorithm is used to obtain the best sequence in the design domain, and the deviation between the final predicted value and the simulation value is less than 3%. After comparing, the research also improves the efficiency of process planning of and medium-sized batches and multiple batches of aerospace engines.