CN-122021121-A - Design method and device for accelerated life test of spherical joint

CN122021121ACN 122021121 ACN122021121 ACN 122021121ACN-122021121-A

Abstract

The invention provides a design method and a device for an accelerated life test of a spherical joint, wherein the method comprises the steps of determining the accelerated stress of the accelerated life test according to the actual use condition of the spherical joint; the method comprises the steps of obtaining a stress spectrum of a spherical joint of a pipeline system under a load corresponding to a preset flight profile by adopting a finite element analysis method, integrating the stress spectrum by adopting a rain flow counting method and a Goodman formula, folding the stress spectrum into an equivalent stress spectrum, obtaining the circulation times corresponding to the acceleration stress of an acceleration life test according to the equivalent stress spectrum, an S-N curve, a Miner damage accumulation theory and a preset total flight time, and determining a test scheme according to the acceleration stress and the circulation times of the acceleration life test. The stress of the spherical joint under the use condition of the airplane is amplified, so that the test times are reduced.

Inventors

YANG BOXIAO
BO JIANLONG
LIU YAJUN
ZHANG YINGJIE

Assignees

太原航空仪表有限公司

Dates

Publication Date: 20260512
Application Date: 20251227

Claims (8)

1. The design method for the accelerated life test of the spherical joint is characterized by comprising the following steps of: 1) Determining acceleration stress of an acceleration life test according to actual use conditions of the spherical joint; 2) Adopting a finite element analysis method to obtain a stress spectrum of the spherical joint of the pipeline system under the load corresponding to the preset flight profile, adopting a rain flow counting method and a Goodman formula to integrate and fold the stress spectrum into an equivalent stress spectrum; 3) Acquiring the circulation times corresponding to the acceleration stress of the accelerated life test according to the equivalent stress spectrum, the S-N curve, the Miner damage accumulation theory and the preset total flight times; 4) And determining a test scheme according to the acceleration stress and the cycle times of the acceleration life test.
2. The method of claim 1, wherein the actual operating conditions include a maximum operating temperature and a maximum operating pressure, and wherein determining the accelerated life test acceleration stress based on the actual operating conditions of the ball joint comprises: and determining the acceleration stress of the accelerated life test according to the maximum working temperature, the maximum working pressure and the maximum compensation quantity of the spherical joint.
3. The method of claim 1, wherein the step of obtaining the number of cycles corresponding to the acceleration stress of the acceleration life test comprises: acquiring accumulated damage of the spherical joint in one flight according to an equivalent stress spectrum, an S-N curve and a Miner damage accumulation theory; determining total damage according to the accumulated damage of the spherical joint in one flight and the preset total number of flights; And acquiring the cycle times corresponding to the acceleration stress of the accelerated life test according to the total damage.
4. The method for designing an accelerated life test of a ball joint according to claim 1, wherein the step of obtaining the number of cycles corresponding to the acceleration stress of the accelerated life test based on the total damage comprises: Acquiring damage of the spherical joint in one fatigue life test cycle according to the acceleration stress and the S-N curve of the acceleration life test; And acquiring the cycle times corresponding to the acceleration stress of the acceleration life test according to the damage and the total damage of the spherical joint in one fatigue life test cycle.
5. An accelerated life test design device for a ball joint, comprising: the acceleration stress acquisition module is used for determining acceleration stress of the acceleration life test according to actual use conditions of the spherical joint; The equivalent stress spectrum acquisition module is used for acquiring the stress spectrum of the spherical joint of the pipeline system under the load corresponding to the preset flight profile by adopting a finite element analysis method, integrating the stress spectrum by adopting a rain flow counting method and a Goodman formula, and folding the integrated stress spectrum into an equivalent stress spectrum with the mean value of 0; The cycle number acquisition module is used for acquiring the cycle number corresponding to the acceleration stress of the acceleration life test according to the equivalent stress spectrum, the S-N curve, the Miner damage accumulation theory and the preset total flight number; And the test scheme acquisition module is used for determining a test scheme according to the acceleration stress and the cycle times of the accelerated life test.
6. The accelerated life test design device of ball joints according to claim 5, wherein the actual usage conditions include a maximum operating temperature and a maximum operating pressure; The accelerated life test acceleration stress acquisition module is specifically used for determining the accelerated life test acceleration stress according to the maximum working temperature, the maximum working pressure and the maximum compensation quantity of the spherical joint.
7. The accelerated life test design device of ball joints according to claim 5, wherein the cycle number acquisition module specifically comprises: The accumulated damage acquisition unit is used for acquiring accumulated damage of the spherical joint in one flight according to an equivalent stress spectrum, an S-N curve and a Miner damage accumulated theory; The total damage acquisition unit is used for determining total damage according to the accumulated damage of the spherical joint in one-time flight and the preset total number of flights; The cycle number acquisition unit is used for acquiring the cycle number corresponding to the acceleration stress of the accelerated life test according to the total damage.
8. The ball joint accelerated life test design device of claim 7, wherein the cycle number acquisition unit is specifically configured to: Acquiring damage of the spherical joint in one fatigue life test cycle according to the acceleration stress and the S-N curve of the acceleration life test; And acquiring the cycle times corresponding to the acceleration stress of the acceleration life test according to the damage and the total damage of the spherical joint in one fatigue life test cycle.

Description

Design method and device for accelerated life test of spherical joint Technical Field The invention belongs to the technical field of ball joint tests, and particularly relates to a ball joint accelerated life test design method and device. Background The spherical joint is mainly used for the high-pressure pipeline system of the aircraft, is a flexible compensation device with strong functionality and high reliability, can compensate stress and displacement of the high-temperature and high-pressure pipeline system caused by temperature change, installation error, mechanical vibration and the like, has the characteristics of light weight, small volume and long service life, is a core compensation component of the high-pressure pipeline system of the aircraft, and plays an important role in the reliability and the safety of the environment-controlled pipeline system. As a core compensation element of the aircraft high-pressure line system, the fatigue life of the ball joint directly influences the service life of the aircraft line system. At present, the fatigue life test of the spherical joint mainly refers to related foreign data, and a design method for the accelerated fatigue life test of the spherical joint based on the use working condition of an airplane is lacking. Disclosure of Invention The invention provides a design method and a device for an accelerated life test of a spherical joint, which are used for reducing test times by amplifying stress of the spherical joint under the use condition of an airplane on the premise of keeping a wear mechanism unchanged, so that the fatigue damage amount of a product in the actual use process can be achieved in a short time in the life test. The invention provides a design method for an accelerated life test of a spherical joint, which comprises the following steps: 1) Determining acceleration stress of an acceleration life test according to actual use conditions of the spherical joint; 2) Adopting a finite element analysis method to obtain a stress spectrum of the spherical joint of the pipeline system under the load corresponding to the preset flight profile, adopting a rain flow counting method and a Goodman formula to integrate and fold the stress spectrum into an equivalent stress spectrum; 3) Acquiring the circulation times corresponding to the acceleration stress of the accelerated life test according to the equivalent stress spectrum, the S-N curve, the Miner damage accumulation theory and the preset total flight times; 4) And determining a test scheme according to the acceleration stress and the cycle times of the acceleration life test. Optionally, the actual use conditions comprise a maximum working temperature and a maximum working pressure, and determining an acceleration stress of an acceleration life test according to the actual use conditions of the spherical joint comprises the following steps: and determining the acceleration stress of the accelerated life test according to the maximum working temperature, the maximum working pressure and the maximum compensation quantity of the spherical joint. Optionally, acquiring the cycle number corresponding to the acceleration stress of the accelerated life test includes: acquiring accumulated damage of the spherical joint in one flight according to an equivalent stress spectrum, an S-N curve and a Miner damage accumulation theory; determining total damage according to the accumulated damage of the spherical joint in one flight and the preset total number of flights; And acquiring the cycle times corresponding to the acceleration stress of the accelerated life test according to the total damage. Optionally, acquiring the cycle number corresponding to the acceleration stress of the accelerated life test according to the total damage includes: Acquiring damage of the spherical joint in one fatigue life test cycle according to the acceleration stress and the S-N curve of the acceleration life test; And acquiring the cycle times corresponding to the acceleration stress of the acceleration life test according to the damage and the total damage of the spherical joint in one fatigue life test cycle. The second aspect of the present invention provides a ball joint accelerated life test design device comprising: the acceleration stress acquisition module is used for determining acceleration stress of the acceleration life test according to actual use conditions of the spherical joint; The equivalent stress spectrum acquisition module is used for acquiring the stress spectrum of the spherical joint of the pipeline system under the load corresponding to the preset flight profile by adopting a finite element analysis method, integrating the stress spectrum by adopting a rain flow counting method and a Goodman formula, and folding the integrated stress spectrum into an equivalent stress spectrum with the mean value of 0; The cycle number acquisition module is used for acquiring the cycle number corresponding to th