CN103983438A - Method for testing service life of turning control system of airplane - Google Patents

Abstract

The invention belongs to the field of undercarriage fatigue life tests and relates to a method for testing the service life of a turning control system of an airplane. The method is characterized in that firstly, the damage ratio of platform take-off and landing to land-based take-off and landing is determined; secondly, the ratio of platform take-off and landing to land-based take-off and landing is determined; thirdly, the frequency of land-based take-off and landing and the frequency of platform take-off and landing are calculated; fourthly, the frequency of turning in the process of land-based take-off and landing and the frequency of turning in the process of platform take-off and landing are counted; fifthly, the reliability coefficient of a test is calculated; sixth, the cycle number of the test is calculated. The method has the advantages that the use conditions of land-based take-off and landing and platform take-off and landing are considered, the design of the test better accords with real use conditions, and a test result is more accurate.

Description

A kind of aircraft turn control lifetime of system test method

Technical field

The invention belongs to undercarriage fatigue life test field, relate to multi-platform use undercarriage turn control lifetime of system test method.

Background technology

Aircraft is different at continental rise from the service condition of platform.Platform landing is obviously serious to the undercarriage damage of aircraft, the life-span of greatly reducing undercarriage.Meanwhile, the requirement using in order to meet platform, undercarriage turn control system also there are differences compared with land airplane, and larger angle of turn can be provided.How to determine and to become a major issue in undercarriage Intensity Design the serviceable life of turn control system according to multi-platform service condition.

Durability analysis and the experimental technique of land airplane undercarriage turn control system are comparative maturities, but can not solve two key issues that undercarriage control system platform uses:

1) landing-gear actuation lifetime of system index will match with the index of aging of undercarriage, and reflects platform, the continental rise service condition of undercarriage.

2) landing-gear actuation lifetime of system will embody the singularity that platform uses, and reflects the impact on the undercarriage life-span on wide-angle turning situation.

Summary of the invention

The object of the invention is: determine undercarriage turn control lifetime of system assessment method under the multi-platform service condition of aircraft.

Technical scheme of the present invention is: a kind of aircraft turn control lifetime of system method for testing, it is characterized in that using damage recently to determine the period of the test of turning according to platform, continental rise, and comprise the steps:

The first, determine the damage ratio that platform takeoff and landing and continental rise rise and fall

No matter undercarriage uses all and can damage generation between rising and falling at platform or at continental rise.Obviously, the experimental enviroment of platform is more harsh.The damage that definite object of damaging ratio is exactly a definite platform takeoff and landing is equivalent to how many times continental rise and rises and falls.

$\mathrm{\ζ}=\frac{\mathrm{\Σ}\frac{1}{n_{i.\mathrm{jz}}}}{\mathrm{\Σ}\frac{1}{n_{i.\mathrm{lj}}}}$

Wherein: for platform uses, the damage that undercarriage is produced of rising and falling

for continental rise uses, the damage that undercarriage is produced of rising and falling

The second, determine the ratio that platform takeoff and landing and continental rise rise and fall

Provide that continental rise rises and falls and the ratio k of platform takeoff and landing, this coefficient is artificially given according to the request for utilization of aircraft.This coefficient need to be considered the worst situation of turning system.

The 3rd, calculate continental rise use and platform and use the number that rises and falls

On 1 and 2 basis, according to damage than and platform takeoff and landing and the continental rise ratio of rising and falling calculate continental rise use and the platform use number that rises and falls.Formula is as follows:

$\left\{\begin{array}{c}{N}_{\mathrm{lj}}+\mathrm{\ζ}\·N_{\mathrm{jz}}=N_{\mathrm{jz}}\\ \frac{N_{\mathrm{lj}}}{N_{\mathrm{jz}}}=k\end{array}\right.$

Wherein: N _ljfor continental rise uses the number that rises and falls, N _jzplatform uses the number that rises and falls, N _jzfor continental rise only uses the number that rises and falls, it in formula, is known quantity.

The 4th, statistics continental rise rises and falls and the turning situation of platform takeoff and landing

The use of statistics continental rise and platform use type and the number of times of the turning of each appearance of rising and falling.Statistical conditions can represent by matrix M:

$M_1=\left[\begin{array}{cc}m11& m12\\ m21& m22\end{array}\right]$

Wherein: m11 represents one of the continental rise common turning number of times that rises and falls

M21 represents one of the continental rise wide-angle traction turning number of times that rises and falls

M12 represents one, the platform common turning number of times that rises and falls

M22 represents one, the platform wide-angle traction turning number of times that rises and falls

The 5th, calculate the reliability coefficient of test

Reliability coefficient is for ensureing the safety of system.The relation of test cycle number and index of aging is as follows:

Reliability coefficient is defined as follows::

${\mathrm{\η}}_{\mathrm{\Σ}}=\underset{i=1}{\overset{4}{\mathrm{\Π}}}{\mathrm{\η}}_i={\mathrm{\η}}_1{\mathrm{\η}}_2{\mathrm{\η}}_3{\mathrm{\η}}_4$

Wherein: η ₁, η ₂, η ₃, η ₄to have considered respectively temperature, destruction hazard level, load confidence level and tired dispersed correction factor.

The 6th, calculate the period of test

Determine the test cycle number of each state in test according to the result of calculation of 1 to 5 step

$M=M_1\×N\×{\mathrm{\η}}_{\mathrm{\Σ}}=\left[\begin{array}{cc}m11& m12\\ m21& m22\end{array}\right]\×\left[\begin{array}{cc}{N}_{\mathrm{lj}}& 0\\ 0& N_{\mathrm{jz}}\end{array}\right]\×{\mathrm{\η}}_{\mathrm{\Σ}}$

Advantage of the present invention is:

1) new method, taking land airplane undercarriage turning durability test as basis, is used with the ratio of land use and can be determined index of aging by platform.

2), if line using situation changes, can determine the impact on undercarriage turn control system according to service condition.

3) unify land-based test and platform service test, without carrying out twice test, just can determine the life-span of turn control system by single test, economical and efficient.

Embodiment

Suppose that the complete continental rise of aircraft uses, the undercarriage life-span is 3000 to rise and fall.It is 2 that platform uses the damage ratio using with continental rise.The land number that rises and falls is 2 with the ratio of platform takeoff and landing number.One of continental rise use is risen and fallen and is handled turning 16 times, and 4 tractions are turned; One of platform use is risen and fallen and is handled turning 16 times, and 2 tractions are turned.

Can be determined by above-mentioned condition:

One, calculate damage ratio

$\mathrm{\ζ}=\frac{\mathrm{\Σ}\frac{1}{n_{i.\mathrm{jz}}}}{\mathrm{\Σ}\frac{1}{n_{i.\mathrm{lj}}}}=2$

Two, determine the land ratio several and platform takeoff and landing number of rising and falling

$\frac{N_{\mathrm{lj}}}{N_{\mathrm{jz}}}=2$

Three, calculate continental rise use and platform and use the number that rises and falls

3000=N _lj+2N _jz

$\frac{N_{\mathrm{lj}}}{N_{\mathrm{jz}}}=2$

Solve: N _lj=1500, N _jz=750

Four, the statistics continental rise turning situation of rising and falling with one of platform takeoff and landing of rising and falling

$M_1=\left[\begin{array}{cc}m11& m12\\ m21& m22\end{array}\right]=\left[\begin{array}{cc}16& 16\\ 4& 2\end{array}\right]$

Five, calculate the reliability coefficient of test

${\mathrm{\η}}_{\mathrm{\Σ}}=\underset{i=1}{\overset{4}{\mathrm{\Π}}}{\mathrm{\η}}_i={\mathrm{\η}}_1{\mathrm{\η}}_2{\mathrm{\η}}_3{\mathrm{\η}}_4=5$

Six, durability test period is calculated as follows:

$M=M_1\×N\×{\mathrm{\η}}_{\mathrm{\Σ}}=\left[\begin{array}{cc}16& 16\\ 4& 2\end{array}\right]\×\left[\begin{array}{cc}1500& 0\\ 0& 750\end{array}\right]\×5$

$=\left[\begin{array}{cc}120000& 60000\\ 30000& 750\end{array}\right]$

Result of calculation shows: continental rise situation is handled to turn and carried out 120000 times, and traction is turned and carried out 30000 times; Platform situation is handled and turned is 60000 times, and it is 750 times that traction is turned.

Claims (1)

1. an aircraft turn control lifetime of system method for testing, is characterized in that, comprises the steps:

The first, determine the damage ratio that platform takeoff and landing and continental rise rise and fall

The damage of determining a platform takeoff and landing is equivalent to how many times continental rise and rises and falls:

Wherein: for platform uses, the damage that undercarriage is produced of rising and falling

for continental rise uses, the damage that undercarriage is produced of rising and falling

The second, determine the ratio that platform takeoff and landing and continental rise rise and fall

Provide that continental rise rises and falls and the ratio k of platform takeoff and landing, this coefficient is artificially given according to the request for utilization of aircraft, and this coefficient need to be considered the worst situation of turning system.

The 3rd, calculate continental rise use and platform and use the number that rises and falls

On the basis of step the first and step the second, according to damage than and platform takeoff and landing and the continental rise ratio of rising and falling calculate continental rise use and the platform use number that rises and falls.Formula is as follows:

Wherein: N _ljfor continental rise uses the number that rises and falls, N _jzplatform uses the number that rises and falls, N _jzfor continental rise only uses the number that rises and falls, it in formula, is known quantity;

The 4th, statistics continental rise rises and falls and the turning situation of platform takeoff and landing

The use of statistics continental rise and platform use type and the number of times of the turning of each appearance of rising and falling.Statistical conditions can represent by matrix M:

Wherein: m11 represents one of the continental rise common turning number of times that rises and falls

M21 represents one of the continental rise wide-angle traction turning number of times that rises and falls

M12 represents one, the platform common turning number of times that rises and falls

M22 represents one, the platform wide-angle traction turning number of times that rises and falls

The 5th, calculate the reliability coefficient of test

Reliability coefficient is for ensureing the safety of system.The relation of test cycle number and index of aging is as follows:

Reliability coefficient is defined as follows::

Wherein: η ₁, η ₂, η ₃, η ₄to have considered respectively temperature, destruction hazard level, load confidence level and tired dispersed correction factor;

The 6th, calculate the period of test

Determine the test cycle number of each state in test according to the result of calculation of 1 to 5 step

。