Research On Bolt Tightening Strategy Of Disc-shaft Structure Under The Constraint Of Rabbet Research On Bolt Tightening Strategy Of Disc-shaft Structure Under The Constraint Of Rabbet

The low-pressure turbine shaft-disc is the core rotor component of the turbofan aero engine and is the assembly reference for rotor components such as high-pressure turbines and high-pressure compressors.The structure of the disc shaft rotor member is relatively complicated,and there are many bolt holes on the mounting side,and the centering positioning function in the assembly process is realized by the interference fit of the anchor structure.Due to the existence of the stop interference constraint,under the same multi-bolt fastening strategy,the assembly deformation form of the disc shaft member with the anchor structure under the bolt fastening is different from the assembly deformation of the disc shaft member without the end structure,especially There are significant differences in the size and orientation of the assembly deformation.At the same time,the multi-bolt fastening strategy directly affects the assembly accuracy of the low-pressure turbine shaft-disc,which indirectly affects the assembly accuracy of other rotor components based on the low-pressure turbine shaft-disc.Increasing the low-pressure turbine shaft-disc assembly accuracy and the reliability of bolt fastening are important for the overall operating life of the aero-engine.In order to improve the assembly precision of the shaft member with the stop structure and reduce the dispersion of the final residual preload of the multi-bolt connection,the finite element parameter model of the multi-bolt coupling disc with the stop structure is established.The solid-state strategy and structural geometric parameters are used to analyze the assembly deformation law of the disc shaft and the distribution law of the final residual pre-tightening force of the bolt.In the multi-bolt fastening strategy research on the assembly deformation of the shaft member of the anchor structure,the initial distribution position of the adjacent fastening bolts directly affects the assembly deformation distribution of the connected parts during the multi-bolt fastening process,which in turn determines the multi-bolt tightening.The formulation of a solid strategy.Therefore,this paper establishes a finite element model of the single-bolt fastening,two-bolt fastening with different phase distribution and a multi-bolt fastening disc structure.Taking the relative change of assembly deformation and relative phase angle under each loading step as the starting point,the influence of the geometric parameters of the single-bolt lower shaft model on the assembly deformation of the disc shaft model and the adjacent loading step bolts are simulated and analyzed.The influence of the phase distribution on the assembly deformation of the disc shaft model and the influence of the multi-bolt tightening sequence and the geometric parameters of the connected parts on the assembly deformation of the disc shaft model.In the study of the pre-tightening force distribution law of the bolts in the multi-bolt fastening process of the shaft structure of the disc structure,the paper analyzes and analyzes the positional distribution of the adjacent loading step bolts and the elastic interaction of the bolts in the bolt tightening process of the disc shaft model.The relationship between the multi-bolt fastening sequence and the geometrical parameters of the disc shaft model on the bolt preload force distribution is analyzed.Then,taking the disk shaft with the stop structure as the experimental object,the assembly deformation law of the test piece in the multi-bolt fastening process and the influence of the position distribution of the adjacent loading step bolt on the elastic interaction of the bolt are verified,and the assembly deformation is reduced.The pre-tightening force of the bolt is the target,and a series of recommendations for the multi-bolt fastening strategy of the shaft structure of the disc structure are proposed.These recommendations provide a reference for the study of multi-bolt fastening strategies for disk-rotor components with a vented structure such as a turbofan aero-engine low-pressure turbine shaft-disc.Finally,the paper analyzes the shortcomings in this research,and combines the current research trend of multi-bolt fastening strategy to make a prospect for the research on the multi-bolt fastening strategy of the future axle structure.