A Design Method of Crack Propagation Characteristic Simulation Parts of Centrifugal Impeller Boss

Abstract

The invention relates to a centrifugal impeller boss crack propagation feature simulator design method. The method comprises the following steps: acquiring a geometric model of a centrifugal impeller,measuring a transition fillet semi-diameter of a boss structure and a boss radial length; acquiring a working condition of the centrifugal impeller and the material performance parameter under the working condition; establishing a centrifugal impeller finite element analysis model, computing to acquire the stress maximum point of the boss part of the centrifugal impeller; taking the rectangular slab test piece as the basic shape, wherein boss structures are arranged on symmetric locations at two sides of the slab, and the transition fillet semi-diameters of the boss and the rectangular slab and the boss radial length and the actual structure are consistent; enabling the maximum stress at the stretching direction of the simulator close to the boss location is consistent with the actual structure by adjusting the test piece length method, and guaranteeing that the stress gradient is same; checking the relation of the stress strength factor of the simulator and the test piece thickness,determining the thickness of the test piece, wherein the obtained simulator can simulate the stress strain field of the centrifugal impeller boss structure and can be used for developing crack extension test.

Description

Technical field [0001] The invention relates to a design method for a simulation part of a crack propagation characteristic of an aeroengine centrifugal impeller boss. It is a design method for a simulation part of a crack propagation characteristic which can consider the stress concentration and stress gradient of the centrifugal impeller structure, belonging to the technical field of aerospace engines. Background technique [0002] The complex structural features of the centrifugal impeller in aero-engines tend to cause stress concentration in a local area, resulting in a 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 adopted, and the load is approximated as a uniform load at each crack growth increment. When the crack growth increment decreases To a certain exten...

AI Technical Summary

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 plate tongue and groove structure design ensures that the maximum tensile force, stress gradient, and strain 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 low-cycle Fatigue life test instead of fatigue crack growth test

Images