Method for designing crack propagation characteristic simulator of centrifugal impeller central hole

Abstract

A method for designing a crack propagation characteristic simulator of a central hole of a centrifugal impeller include such steps as obtaining a geometric model of that centrifugal impeller, measurea diameter and a thickness of the central hole structure, measuring the diameter and the thickness of the centrifugal impeller, measuring the diameter and the thickness of the centrifugal impeller, measuring the diameter and the thickness of the centrifugal impeller, measuring the diameter and the thickness of the centrifugal impeller, (2) obtaining the working conditions of the centrifugal impeller and the material performance parameters under the working conditions, including load, temperature, elastic modulus, yield strength and so on; (3) Establishing the finite element static analysis model of centrifugal impeller, calculating and obtaining the maximum circumferential stress point at the center hole of centrifugal impeller, and obtaining the circumferential stress value and the circumferential stress gradient of the point; (4) Based on the basic shape of the plate simulator with symmetrical circular notch, the central hole structure simulator is designed, so that the maximum stress along the direction of tensile loading on the stress concentration point of the simulator is equal to the maximum circumferential stress in the actual central hole structure, and the stress gradientis ensured to be the same; (5) Calculate the stress intensity factor of the simulator and determine the thickness of the simulator.

Description

technical field [0001] The invention relates to a design method for a crack propagation characteristic simulation part of a centrifugal impeller center hole structure of an aeroengine, which is a design method for a crack propagation characteristic simulation part that can consider the stress concentration and stress gradient of the centrifugal impeller structure, and belongs to the technical field of aerospace engines . Background technique [0002] The complex structural features of centrifugal impellers in aeroengines tend to cause stress concentration in local areas, resulting in non-uniform distribution of the load at the far end of the crack along the crack propagation path. Since the crack growth test based on standard parts cannot reflect the stress concentration in the local area, the method of discrete crack growth steps is generally used, and the load is approximated as a uniform load on each crack growth increment. When the crack growth increment decreases To a ...

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Problems solved by technology

[0004] Existing literature "Yang Xingyu, Dong Liwei, Geng Zhongxing, et al. Design and test of low-cycle fatigue simulation parts of a compressor disc [J]. Aerodynamics Journal, 2008, 23(10): 1829-1834" according to the compressor The low-cycle fatigue life test of the tenon-groove structure design ensures that the maximum tensile force and stress gradient of the simulated part are relatively consistent with the actual structure, but the design and evaluation of the characteristics related to crack growth have not been carried out. The test piece can be applied to the low-cycle fatigue life test , instead of fatigue crack growth test

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