A method and device for detecting the fastening force of a low-pressure turbine shaft disk of an aeroengine based on the principle of speckle interference

Abstract

The invention discloses an aeroengine low pressure turbine shaft disc fastening force detection method and an aeroengine low pressure turbine shaft disc fastening force detection based on speckle interferometry. The aeroengine low pressure turbine shaft disc fastening force detection method comprises steps that a relation between a low pressure turbine bolt pre-tightening force and displacement and distribution of a disc surface is acquired, and the disc surface displacement of the low pressure turbine shaft disc structure is tested during an assembly process or after the assembly process, and the tightening state of the bolt is determined, and the deviation value of the pre-tightening force is determined. The disc surface displacement is measured according to the speckle interferometry, and disc surface displacement changing characteristics in a certain range are acquired at the same time, and therefore the pre-tightening state determining is carried out by combing with the whole changing rule of the disc surface displacement, and by combining with a series of stable position points, the disc surface displacement differences of which are constants, during the pre-tightening process, a speckle pattern mismatch problem generated during measurement before and after the pre-tightening of the bolt and during a multi-position measuring process is solved, and therefore the determining of the pre-tightening states of the plurality of bolts in the low pressure turbine shaft disc are supported.

Description

technical field [0001] The invention belongs to the assembly technology of aero-engines, in particular to a method and device for detecting the fastening force of a low-pressure turbine shaft disk of an aero-engine based on the principle of speckle interference. Background technique [0002] The low-pressure turbine of an aeroengine is a structure that transmits the power of the low-pressure turbine disk to the fan. It has a high operating speed and a large transmission torque value. The assembly work of the low-pressure turbine shaft disc is mainly composed of bolt tightening operations. The tightening process parameters such as tightening force, tightening sequence, and tightening times will affect the pre-tightening force of the bolts, and then affect the contact stress of the shaft-disc connection interface, the disc surface, etc. Deformation and low-pressure turbine shaft coaxiality, low-pressure turbine shaft disc dynamic stiffness and dynamic stability will have a sig...

AI Technical Summary

Problems solved by technology

However, it is not allowed to make an axially extending channel on the surface of the bolts used for the low-pressure turbine shaft-disc connection of the aero-engine; The comprehensive effect of the bolt and the connected parts, the deformation mechanism and shape of different bolts are different from the single bolt deformation studied by Sayed A. Nassar, Aidong Meng, etc. , it is necessary to measure the speckle images at different positions before and after deformation. Due to the change of the reference coordinates of the disk surface during the preloading process and the repeated positioning error of the feed system during the measurement process, the speckle field will not match before and after deformation, and the correlation will fade. The interference fringes are seriously degraded, and the deformation information of the disk surface cannot be obtained by direct inversion and subtraction. The complex speckle field mismatch poses a problem for the detection of the fastening force of the low-pressure turbine shaft disk based on the principle of speckle interference.

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