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Method for predicting fatigue life of secondary extrusion strengthened hole

A fatigue life prediction and secondary extrusion technology, which is applied in design optimization/simulation, special data processing applications, instruments, etc., can solve the problem of no secondary extrusion strengthening hole fatigue life prediction method, etc., to reduce the number of tests and simulations cost effect

Pending Publication Date: 2020-10-02
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the prediction method for the fatigue life of the cold extrusion strengthening hole is relatively broad, and there is currently no prediction method for the fatigue life of the secondary extrusion strengthening hole

Method used

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  • Method for predicting fatigue life of secondary extrusion strengthened hole
  • Method for predicting fatigue life of secondary extrusion strengthened hole
  • Method for predicting fatigue life of secondary extrusion strengthened hole

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Embodiment 1

[0036] The method for predicting the fatigue life of secondary extrusion strengthening holes of the present invention will be specifically described below with application examples.

[0037] The actual working condition in this embodiment is that M42 high-cobalt steel mandrel is used to extrude TB6 titanium alloy lug 1 and 1Cr17Ni3A stainless steel bushing 2, wherein the diameter of the bottom hole of the lug is 20 mm, and the diameter of the working section of mandrel 3 for one extrusion is 20.4mm, corresponding to a relative extrusion amount of 2%, the relative extrusion amount used by the bushing 2 is 1.5%-2%.

[0038] (1) First, use the finite element analysis software ABAQUS to establish the secondary extrusion strengthening finite element model according to the actual working conditions. The model consists of lug 1, bushing 2, primary extrusion mandrel 3 and secondary extrusion mandrel 4. Component composition, in the process of extrusion strengthening, firstly extrude t...

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Abstract

The invention provides a method for predicting the fatigue life of a secondary extrusion strengthened hole, which comprises the following steps of: establishing a secondary extrusion strengthened finite element model by utilizing finite element software ABAQUS according to actual working conditions, setting material contact attributes, dividing grids, setting loads and boundary conditions, and performing solving operation; measuring the residual stress distribution condition around the secondary extrusion strengthening hole through a test, and correcting the finite element model based on the measured stress field; and reading a model calculation result in fatigue analysis software MSC. Fatigue, setting material and fatigue load information, associating a load working condition with a timehistory, determining solver parameters, and carrying out prediction analysis on the fatigue life. The method can accurately and efficiently predict the fatigue life of the secondary extrusion strengthened hole, can effectively guide the formulation of a process scheme, and saves the production cost.

Description

technical field [0001] The invention belongs to the field of fatigue life prediction, and relates to a method for predicting the fatigue life of a hole of a key bearing part of a helicopter through secondary extrusion strengthening, which can efficiently and accurately predict the fatigue life of a sample of a secondary extrusion strengthening ear piece. Background technique [0002] The rotor system is the core component of the helicopter, and its parts are the key load-bearing parts of the helicopter. These parts are mostly connected by bolts and riveting. During flight, they are subjected to high-frequency alternating loads. Severe stress concentration often occurs around the holes of these connectors, leading to the initiation of fatigue cracks, and eventually high-cycle fatigue failure. The use of hole extrusion strengthening technology can introduce high residual compressive stress around the hole, thereby improving the fatigue life of parts. At present, the boring an...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F30/15G06F30/17G06F30/23G06F111/10G06F119/02G06F119/14
CPCG06F30/15G06F30/17G06F30/23G06F2111/10G06F2119/02G06F2119/14
Inventor 苏宏华姜廷宇王洋张全利杨长勇傅玉灿徐九华
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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