High-low cycle composite fatigue test piece of turbine disc cold extrusion reinforced hole structure and design method

Abstract

The invention discloses a high-low cycle composite fatigue test piece design method for a turbine disc cold extrusion reinforced hole structure, and the method comprises the steps: obtaining a geometric model of a perforated turbine disc, and simplifying a non-key region; obtaining working conditions of the turbine disc and material performance parameters under all the working conditions; and establishing a finite element analysis model of the perforated wheel disc, and conducting calculating to obtain a hole edge equivalent stress maximum point and a stress gradient. A flat test piece with acenter hole is used as a basic shape, uniaxial tensile loading is used as a basic load form, an examination section of a turbine disc hole structure test piece is designed, and the maximum stress value and distribution of the stress concentration position of the hole edge of the test piece accord with the condition of a real structure by adjusting the width of the test piece, finely adjusting thetensile load and the like. By the modes of adjusting the thickness of the test piece, the frequency and magnitude of the exciting force and the like, the maximum vibration stress value of the hole edge is equal to the maximum vibration stress value of a real wheel disc hole structure, and it is ensured that the loads are all within the optimal working range of the high-low cycle composite fatiguetest system; and a test piece double-wedge-shaped clamping end is designed, and thus the low stress level of the clamping end and the low stress concentration degree of a transition section are guaranteed.

Description

technical field [0001] The invention relates to a high-low cycle composite fatigue test piece and a design method for aero-engine turbine disk cold extrusion strengthening hole structure, which is a kind of low cycle load level, stress gradient, high cycle vibration load and The invention relates to a design method for a fatigue crack initiation test piece of residual stress in a cold extrusion process, and belongs to the technical field of aerospace engines. Background technique [0002] Due to the difference in working load and working environment (temperature environment), the turbine disc and the turbine shaft in the aero-engine often use two materials with different properties, which makes it difficult to form an integral structure by welding the disc and the shaft, and requires an additional design of the connecting structure to connect the turbine. Disc and turbine shaft. Precision bolts are the most common form of connection in aero-engines, and holes need to be dri...

AI Technical Summary

Problems solved by technology

This method is mainly designed for the simulated part of the crack growth test of the turbine tenon and groove structure. In addition, there are the following limitations: (1) the load considered in the design is only the low cyclic load of the single axis; (2) the double wedge surface clamp is not given (3) The stress distribution of the assessment section along the width direction is consistent with the real structure, which is too strict, which increases the difficulty of the design of the test piece, and is not suitable for the design of the crack initiation test simulation piece

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