CN104318127A - Confirmation method of airplane structure calendar safety life - Google Patents

Abstract

The invention discloses a confirmation method of airplane structure calendar safety life. The confirmation method of the airplane structure calendar safety life is characterized by including following steps: 1, confirming a first overhaul period; 2, confirming overhaul intervals; 3, confirming repair times; 4, confirming a remaining service period; 5, obtaining the airplane structures calendar safety life by adding the first overhaul period, all the overhaul intervals, the remaining service period and repair time needed by all overhauls. The confirmation method of the airplane structure calendar safety life has the advantages of being used to confirm the safety service life of an airplane structure, of great importance in guaranteeing of use safety of the airplane structure, capable of providing the basis for reasonably formulating an airplane use plan according to the confirmed airplane structure calendar safety life, and of great importance in achievement of the purposes of bringing airplane structure life potential into full play and improving the life management level of the airplane structure.

Description

The defining method of aircaft configuration calendar safe life

Technical field

The present invention relates to a kind of defining method of aircaft configuration calendar safe life, belong to aircaft configuration and determine longevity technical field.

Background technology

The life-span of aircraft refers to aircraft term of life from the retired grounding of coming into operation under normal service state, refer generally to the structural life-time of airframe, there are two leading indicators: one is the fatigue lifetime considering the effect of flight alternate load, characterizes with pilot time number or the number of times that rises and falls; Two is the calendar lifes considering environmental corrosion effect, characterizes with tenure of use.When the longevity determined by aircaft configuration, no matter be fatigue lifetime or calendar life, include corresponding head and turn over phase, time between overhaul and entire life, and include and repair outline accordingly.In existing life-span management means, when the equivalent pilot time number of aircraft, arbitrary index of rising and falling in number of times and tenure of use three indexs reach the setting when longevity determined by aircraft, all mean that aircaft configuration reaches and use restriction and to the longevity.

For the fatigue lifetime of aircaft configuration, Qi Dingshou determined fatigue lifetime, do not refer to life-span when aircaft configuration destroys, but a safe life restriction with high-reliability, i.e. the fatigue safety life-span.The fatigue of carrying out aircaft configuration determines the longevity, first fatigue and Damage Tolerance Analysis method is adopted to carry out life estimate or fatigue analysis by the critical risk position of each key component to aircaft configuration, to evaluate the requirement that can designed structure reach design index fatigue lifetime; Then verified by full size structure torture test again and judged; Finally Comprehensive Assessment is carried out to analysis and test findings, consider the dispersiveness of aircraft construction material and manufacture level, divided by certain tired dispersion coefficient, provide the fatigue safety life-span of aircaft configuration.Such as, if aircraft structure fatigue life-span obeys logarithm normal distribution, usually will provide the fatigue safety life-span of satisfied 99.9% fiduciary level and 90% confidence level, tired dispersion coefficient gets 4.Therefore, the fatigue safety life-span be one by sampling method determine, for the life value with very high reliability of a group of planes.

For the research of the calendar life of aircaft configuration, Zhang Fuze is at " computation model of metal part corrosion damage calendar life and defining method " (aviation journal, 1999, 20 (1): 75-79), " area life determination that aircraft calendar life is determined " (aviation journal, 2001, 22 (6): 549-552), " aircraft calendar repaired period and total calendar life defining method and estimating formula " (aviation journal, 2005, 26 (4): 458-460) etc. the area life determination determining calendar life of aircraft structure is proposed in article, according to the difference of corrosion environment, work out the corrosion environment spectrum of different corrosion area, carry out the determination of each type calendar life in this region respectively.Zhang Dong is at " determining the method for airframe calendar life " (aviation journal, 1999,20 (6): 558-561) corrosion test doing component by corrosion spectrum is proposed in, measure corrosion speed, then estimate, determine the scheme of calendar life of aircraft structure according to the corrosion damage tolerance limit of component.

But the calendar of present stage is determined the longevity and is directly provided by analysis of experiments result, wherein there is not the process of statistical study, namely there is not the concept of " calendar safe life "; In fact, the calendar life of aircaft configuration is a probable value, and it obeys certain probability distribution rule, and the time of real aircraft structure generation corrosion failure has dispersiveness.Its usage economy of flight safety and aircraft can be threatened owing to corroding the aircraft structural damage caused equally, therefore, for the determination of calendar life of aircraft structure, also should implement reliability design thought.

For this reason, the present invention proposes the concept of aircaft configuration calendar safe life, and establish the defining method of aircaft configuration calendar safe life, for the longevity of determining of aircaft configuration provides technical support.

Summary of the invention

The object of the present invention is to provide a kind of defining method of aircaft configuration calendar safe life, for rationally determining the calendar life of aircaft configuration, safety, economically use aircaft configuration provide Theories and methods support.

In order to realize above-mentioned target, the present invention adopts following technical scheme:

A defining method for aircaft configuration calendar safe life, is characterized in that, comprise the following steps:

Step 1: determine that head turns over the phase

Head is turned over front protection system calendar safe life Y ₁phase Y is turned over the structure head determined by the fatigue safety life-span ₁' compare:

If Y ₁> Y ₁', then by Y ₁' determine headed by turn over the phase;

If Y ₁≤ Y ₁', then by Y ₁the phase is turned over headed by determining;

Step 2: determine time between overhaul

Head is turned over rear protecting system calendar safe life Y ₂with the time between overhaul Y before the arrival determined by the fatigue safety life-span i-th overhaul _i' compare:

If Y ₂> Y _i', then by Y _i' be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system is impaired, then by Y ₂be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system does not have impaired, and Y ₁> Y _i', then by Y _i' be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system does not have impaired, and Y ₁≤ Y _i', then by Y ₂be defined as time between overhaul;

Step 3: determine to repair number of times

Residue pilot time number and time between overhaul pilot time number are compared:

If the residue pilot time number of aircraft after certain overhaul is less than the time between overhaul pilot time number after this overhaul, then this time overhaul is the last overhaul of aircraft;

If the residue pilot time number of aircraft after certain overhaul is greater than the time between overhaul pilot time number after this overhaul, then aircraft can also be repaired next time, until the residue pilot time number after overhaul is less than the time between overhaul pilot time number after overhaul, now, statistics draws the repairing number of times of aircaft configuration;

Step 4: determine to remain the military service cycle

The last time after overhaul, head is turned over rear protecting system calendar safe life Y ₂with structural matrix calendar safe life Y _cbe added, then with structure after last overhaul by the military service cycle Y remaining pilot time number or the number of times that rises and falls and determine _r' compare:

If Y ₂+ Y _c> Y _r', then by Y _r' be defined as remaining the military service cycle;

If Y ₂+ Y _c≤ Y _r', then by Y ₂+ Y _cbe defined as remaining the military service cycle;

Step 5: determine structure calendar safe life

The repairing time of head being turned over phase, all previous time between overhaul, residue military service cycle, all previous overhaul used is added, and namely obtains aircaft configuration calendar safe life.

The defining method of aforesaid aircaft configuration calendar safe life, is characterized in that, under single Service Environment, determines that head turns over front protection system calendar safe life Y ₁process comprise the following steps:

(1), design and manufaction head turn over before protection system simulation test piece;

(2), protection system Environmental Spectrum is worked out;

(3) failure criteria of simulating piece protection system, is determined

First the head carried out under one group of pure fatigue turns over the torture test of pre-structure simulating piece, obtains the median fatigue life N of structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out the failure criteria that comprehensive analysis provides protection system;

(4) fail data of protection system simulating piece, is obtained

When head turns over the damage characteristic that pre-structure simulating piece surfacecti proteon system occurs corresponding to failure criteria, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over front protection system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test;

(5) reliability of, analytical test data, protection system calendar safe life is determined

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\α}}^{\′}}=\stackrel{\‾}{N}-k\·S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained.

The defining method of aforesaid aircaft configuration calendar safe life, is characterized in that, under many Service Environment, determines that head turns over front protection system calendar safe life Y ₁process comprise the following steps:

(1), design and manufaction head turns over pre-structure protection system simulation test piece;

(2), the local environmental spectrum in the different area of being on active service of establishment;

(3) the calendar safe life of protection system under different Service Environment, is determined

Determine that head turns over the calendar safe life of front protection system under each single Service Environment spectrum, the determination detailed process of the calendar safe life under single Service Environment spectrum comprises the following steps:

1. the failure criteria of structural simulation part protection system, is determined

First the head carried out under one group of pure fatigue turns over the torture test of pre-structure simulating piece, obtains the median fatigue life N that head turns over pre-structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out comprehensive analysis and providing the failure criteria that head turns over front protection system;

2. the fail data of protection system simulating piece, is obtained

When head turns over the damage characteristic that pre-structure simulating piece surfacecti proteon system occurs corresponding to failure criteria, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over front protection system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test;

3., determine that head turns over front protection system calendar safe life

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\α}}^{\′}}=\stackrel{\‾}{N}-k\·S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained;

(4), according to application plan prediction calendar safe life

According to the computing method of linear cumulative damage, when the accumulated damage amount of protection system reaches 1, then think that protection system reaches the safe handling restriction of expection, the summation of now corresponding calendar life is regional protection system calendar safe life value of being on active service more.

The defining method of aforesaid aircaft configuration calendar safe life, is characterized in that, under single Service Environment, determines that head turns over rear protecting system calendar safe life Y ₂process comprise the following steps:

(1), design and manufaction head turn over after protection system simulation test piece;

(2), protection system Environmental Spectrum is worked out;

(3) failure criteria of simulating piece protection system, is determined

First the head carried out under one group of pure fatigue turns over the torture test of rear structural simulation part, obtains the median fatigue life N of structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out the failure criteria that comprehensive analysis provides protection system;

(4) fail data of protection system simulating piece, is obtained

There is the damage characteristic corresponding to failure criteria in structural simulation part surfacecti proteon system after head turns over, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over rear protecting system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test;

(5) protection system calendar safe life, is determined

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\α}}^{\′}}=\stackrel{\‾}{N}-k\·S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained.

The defining method of aforesaid aircaft configuration calendar safe life, is characterized in that, under many Service Environment, determines that head turns over rear protecting system calendar safe life Y ₂process comprise the following steps:

(1), design and manufaction head turns over front and head and turns over rear structural shielding system simulation test piece;

(2), the local environmental spectrum in the different area of being on active service of establishment;

(3) the calendar safe life of protection system under different Service Environment, is determined

Determine that head turns over the calendar safe life of rear protecting system under each single Service Environment spectrum with first before turning over, the determination detailed process of the calendar safe life under single Service Environment spectrum comprises the following steps:

1. the failure criteria of structural simulation part protection system, is determined

First turn over the torture test of rear structural simulation part with head before the head carried out under one group of pure fatigue turns over, obtain head and turn over the median fatigue life of pre-structure and the first median fatigue life turning over rear structure, the median fatigue life of structure is all counted and is made N ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, by the protection system damage characteristic of torture test life-span partially short testpieces in the testpieces of observing equivalence corrosion i, carry out comprehensive analyze provide head turn over before and first failure criteria of turning over rear protecting system;

2. the fail data of protection system simulating piece, is obtained

There is the damage characteristic corresponding to failure criteria in structural simulation part surfacecti proteon system after turning over head before head turns over, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, before contrast head turns over and head turn over rear protecting system failure criteria, from the testpieces finished torture test and not yet do torture test, obtain valid data respectively;

3., determine that head turns over front and head and turns over rear protecting system calendar safe life

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\α}}^{\′}}=\stackrel{\‾}{N}-k\·S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained;

(4), according to application plan prediction calendar safe life

According to the computing method of linear cumulative damage, when the accumulated damage amount of protection system reaches 1, then think that protection system reaches the safe handling restriction of expection, the summation of now corresponding calendar life is regional protection system calendar safe life value of being on active service more.

The defining method of aforesaid aircaft configuration calendar safe life, is characterized in that, determines structural matrix calendar safe life Y _cprocess comprise the following steps:

(1) structural matrix simulation test piece, is manufactured and designed;

(2), programming structure local matrix Environmental Spectrum and structural loads spectrum;

(3) the matrix calendar safe life of aircaft configuration, is determined

For the corrosion fatigue key component in loaded structure, determine that the step of its matrix calendar safe life is as follows:

1. the fatigue safety life-span of overall aircraft, is determined;

2., by testpieces be divided into some groups, often organize testpieces under accelerated environment spectrum, experience the different pre-etching cycles;

3., after pre-etching, under the loading spectrum of establishment, torture test is carried out to fracture;

4., under selected fiduciary level and confidence level, the safe life often organizing prior-corroded fatigue testpieces is calculated;

5., by the prior-corroded fatigue safe life often organizing testpieces carry out matching, simulate a pre-etching cycle to the influence curve in fatigue safety life-span;

6., the Residual Damage degree of computation structure matrix after protection system lost efficacy;

7., in the pre-etching cycle to the influence curve in fatigue safety life-span being determined the point corresponding with the residue pilot time number of aircraft or the application plan of aircraft, thus determine the year injury tolerance of structural matrix under its corresponding flight rate or under its application plan, namely Residual Damage degree is obtained the calendar safe life of corrosion fatigue key component divided by year injury tolerance;

For the stress corrosion key component in loaded structure, determine that the step of its matrix calendar safe life is as follows:

1., the position and the direction of check that the most easily produce stress corrosion crack in structure is determined;

2., by testpieces some groups are divided into, according to the position and the direction of check that the most easily produce stress corrosion crack, to the initial crack of the preset different length of the testpieces of difference group;

3. the stress corrosion (cracking) test of each group of testpieces, is carried out;

4., the propagation law of identified sign corrosion cracking and Critical fracture length;

5. the dispersion coefficient under given fiduciary level and confidence level, is tried to achieve;

6., namely stress corrosion cracking (SCC) expansion time is obtained the calendar safe life of stress corrosion key component divided by dispersion coefficient;

For not loaded structure, determine that the step of its matrix calendar safe life is as follows:

1. the criterion of the disabler of not loaded structure, is determined;

2., carry out the corrosion test of testpieces, at set intervals extraction portion separating tests part measure the maximum corrosion depth of testpieces, obtain meeting under this abrasion cycle the matrix maximum corrosion depth that given fiduciary level and confidence level require;

3., by meeting the matrix maximum corrosion depth that given fiduciary level and confidence level require under different abrasion cycle comprehensively analyzing, obtaining abrasion cycle when structure reaches failure criteria, the aforementioned abrasion cycle i.e. matrix calendar safe life of not loaded structure.

Usefulness of the present invention is:

1, the defining method of aircaft configuration calendar safe life that provides of the present invention, may be used for the safe service life determining aircaft configuration, to ensureing that the use safety of aircaft configuration is significant;

2, the aircaft configuration calendar safe life by determining, can provide foundation for reasonably formulating aircraft utilization plan, and to giving full play to Aircraft Structural Life potentiality, the life-span management level promoting aircaft configuration is significant.

Accompanying drawing explanation

Fig. 1 is the concept system figure of aircaft configuration calendar safe life;

Fig. 2 is the process flow diagram of determination aircaft configuration calendar safe life of the present invention.

Embodiment

Aircaft configuration calendar safe life of the present invention comprises: get off the plane structure calendar safe life and many Service Environment of single Service Environment is got off the plane structure calendar safe life, be characterized in: protection system calendar safe life, structural matrix calendar safe life and the head that determined by structural fatigue safe life are turned over the phase and time between overhaul considers, determine that the head of aircaft configuration turns over phase, time between overhaul and residue active time, then carry out phase Calais and determine aircaft configuration calendar safe life.

First, the concept of aircaft configuration calendar safe life is introduced.

Aircaft configuration calendar safe life is that aircaft configuration is under environment for use and service condition, can complete the calendar service time of its using function according to the determined aircaft configuration of safe-life design criterion, the aircaft configuration namely obtained by fail-safe analysis has the calendar life restriction of pole low corrosion failure probability.

The concept system of aircaft configuration calendar safe life as shown in Figure 1.

The calendar safe life of airframe depends on the calendar life of the main bearing member of corrosion-vulnerable in housing construction, and the representative perishable main bearing member choosing aircraft is the key determining airframe calendar safe life.

For concrete aircaft configuration, body structure surface all has protection system, plays the effect that isolation environment medium contacts with matrix material, in its term of validity, can prevent matrix material from corroding.After surfacecti proteon system lost efficacy, the matrix material of structure will produce with surrounding medium and contact and corrode, if protection system can not be repaired, in time along with the growth of active time after losing efficacy, the corrosion of matrix material further develops, and will finally cause the disabler of structure.Therefore, the calendar safe life of aircaft configuration is made up of the calendar safe life of protection system and the calendar safe life of structural matrix.

The calendar safe life of surfacecti proteon system refers to that surfacecti proteon system limits the service time that generating function did not lose efficacy under certain fiduciary level and confidence level.The structure (as undercarriage etc.) poor especially on the key structure and matrix material corrosion resistivity that affect flight safety, the calendar safe life of protection system is relevant with the safety in utilization of structure, should choose higher fiduciary level and confidence level; To other aircaft configuration, after protection system inefficacy, structural matrix generation corrosion failure still needs the regular hour, the factors such as structural safety, overhaul time, the cost of repairs should be considered, fiduciary level and the confidence level of protection system is determined from most economical angle, therefore, the calendar safe life of aircaft configuration protection system is main relevant to its usage economy of structure.

The protection system of aircaft configuration is generally divided into multilayer, and it is the most perfect when structure is dispatched from the factory, also the strongest to the protective effect of structural matrix; After a period of time is on active service by aircraft, the surfacecti proteon system of structure is damaged, and the protection system of some types is recoverable when structure overhaul, as finish paint, priming paint etc., and the protection system of some types cannot be repaired when structure overhaul, as anodic oxide coating, aluminium coating etc.If surfacecti proteon system has been corroded to internal layer overhaul first (head turns over) is front, the protective layer of unrepairable is caused to there occurs damage, then head turns over the state of rear protecting system than the aircraft delivery time difference, and the calendar safe life that its calendar safe life also turns over front protection system than head is little.Therefore, the calendar safe life of protection system is divided into two classes: head turns over the calendar safe life of pre-structure protection system and the first calendar safe life turning over rear structural shielding system.

Head turn over pre-structure protection system calendar safe life refer to aircraft delivery after the calendar life restriction with particular etch failure probability corresponding to structural shielding system status, it is main, and first with structure to turn over the determination of phase relevant.

Head turns over rear structural shielding system calendar safe life and refers to the calendar life restriction with particular etch failure probability that the structural shielding system status of aircraft after overhaul is corresponding, and it is main relevant with the determination of structure time between overhaul.

The calendar safe life of structural matrix refers to when not having surfacecti proteon system to protect, and structural matrix limits the service time that generating function did not lose efficacy under very high-reliability and confidence level.Structural matrix material corrodes, and will directly affect the Function of structure entirety, threatens flight safety.Therefore, the calendar safe life of structural matrix is relevant to the safety in utilization of structure, must choose a very high fiduciary level, make structural matrix have extremely low corrosion failure probability within its calendar safe life phase, to guarantee the use safety of structure.

Protection system calendar safe life and structural matrix calendar safe life constitute aircaft configuration calendar safe life.Aircaft configuration calendar safe life may be used for the life-span management of aircaft configuration, relevant with determining the calendar active time of aircaft configuration, also should comprise for the head reached corresponding to structure overhaul that this active time carries out turns over the contents such as phase, time between overhaul and maintenance measures.

Next, the defining method of aircaft configuration calendar safe life of the present invention is introduced.

The aircaft configuration calendar safe life that the present invention sets up is based upon and determines on protection system calendar safe life and structural matrix calendar safe life basis.Protection system calendar safe life, structural matrix calendar safe life and the head that determined by structural fatigue safe life are turned over the phase to the method and time between overhaul considers, and carries out phase Calais and determine aircaft configuration calendar safe life.

Aircaft configuration calendar safe life with the year number of being on active service for base unit, if the military service area surroundings of aircraft residing within the safe life phase is close, then can think that aircraft is on active service under single environment, only need to work out aircraft institute under arms area corrode that compose can by testing and analyze the calendar safe life obtaining aircaft configuration year; If aircraft is on active service in different regions that its lifetime internal environment differs greatly, then think that aircraft is on active service in a variety of contexts, need the year corrosion spectrum working out different regions to carry out test and analysis obtains structure calendar safe life.

Below in conjunction with Fig. 2 and specific embodiment, concrete introduction is done to the present invention.

Single Service Environment is got off the plane structure calendar safe life Y _tdetermination

Step 1: determine that head turns over the phase

First, determine that head turns over front protection system calendar safe life Y ₁, specifically comprise the following steps:

(1), design and manufaction head turn over before protection system simulation test piece.

(2), protection system Environmental Spectrum is worked out.

(3) failure criteria of simulating piece protection system, is determined:

First the head carried out under one group of pure fatigue turns over the torture test of pre-structure simulating piece, obtains the median fatigue life N of structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out the failure criteria that comprehensive analysis provides protection system.

(4) fail data of protection system simulating piece, is obtained:

When head turns over the damage characteristic that pre-structure simulating piece surfacecti proteon system occurs corresponding to failure criteria, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over front protection system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test.

(5) reliability of, analytical test data, protection system calendar safe life is determined:

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\α}}^{\′}}=\stackrel{\‾}{N}-k\·S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained.

Then, head is turned over front protection system calendar safe life Y ₁phase Y is turned over the structure head determined by the fatigue safety life-span ₁' compare:

If Y ₁> Y ₁', illustrate that protection system is reaching Y ₁' time also do not lose efficacy, then by Y ₁' determine headed by turn over the phase;

If Y ₁≤ Y ₁', illustrate if turned over according to the head of fatigue safety life control aircraft, protection system possibility premature failure, threatens flight safety, then by Y ₁the phase is turned over headed by determining.

Step 2: determine time between overhaul

First, determine that head turns over rear protecting system calendar safe life Y ₂, specifically comprise the following steps:

(1), design and manufaction head turn over after protection system simulation test piece.

(2), protection system Environmental Spectrum is worked out.

(3) failure criteria of simulating piece protection system, is determined:

First the head carried out under one group of pure fatigue turns over the torture test of rear structural simulation part, obtains the median fatigue life N of structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out the failure criteria that comprehensive analysis provides protection system.

(4) fail data of protection system simulating piece, is obtained:

There is the damage characteristic corresponding to failure criteria in structural simulation part surfacecti proteon system after head turns over, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over rear protecting system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test.

(5) protection system calendar safe life, is determined:

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\α}}^{\′}}=\stackrel{\‾}{N}-k\·S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained.

Then, head is turned over rear protecting system calendar safe life Y ₂with the time between overhaul Y before the arrival determined by the fatigue safety life-span i-th overhaul _i' compare:

If Y ₂> Y _i', then by Y _i' be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system is impaired, then by Y ₂be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system does not have impaired, and Y ₁> Y _i', in the case, protection system can be returned to state when dispatching from the factory during structure overhaul, can Y be used ₁as the protection system calendar safe life after overhaul, then by Y _i' be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system does not have impaired, and Y ₁≤ Y _i', then by Y ₂be defined as time between overhaul.

Step 3: determine to repair number of times

Residue pilot time number and time between overhaul pilot time number are compared:

If the residue pilot time number of aircraft after certain overhaul is less than the time between overhaul pilot time number after this overhaul, then this time overhaul is the last overhaul of aircraft, i.e. N=i;

If the residue pilot time number of aircraft after certain overhaul is greater than the time between overhaul pilot time number after this overhaul, then aircraft can also be repaired next time, i.e. i=i+1, until the residue pilot time number after overhaul is less than the time between overhaul pilot time number after overhaul, now, statistics draws the repairing number of times of aircaft configuration.

Step 4: determine to remain the military service cycle

First, structural matrix calendar safe life Y is determined _c, specifically comprise the following steps:

(1) structural matrix simulation test piece, is manufactured and designed.

(2), programming structure local matrix Environmental Spectrum and structural loads spectrum.

(3) the matrix calendar safe life of aircaft configuration, is determined:

Aircaft configuration is divided into loaded structure and non-loaded structure, introduces the defining method of its matrix calendar safe life below respectively.

First, the defining method of the matrix calendar safe life of loaded structure is introduced.

Loaded structure in aircaft configuration, its biggest threat being corroded environmental impact is generally corrosion fatigue or stress corrosion crack.

For corrosion fatigue key component, determine that the step of its matrix calendar safe life is as follows:

1. the fatigue safety life-span of overall aircraft, is determined.

2., by testpieces be divided into some groups, often organize testpieces under accelerated environment spectrum, experience the different pre-etching cycles.

3., after pre-etching, under the loading spectrum of establishment, torture test is carried out to fracture.

4., under selected fiduciary level and confidence level, the safe life often organizing prior-corroded fatigue testpieces is calculated.

5., by the prior-corroded fatigue safe life often organizing testpieces carry out matching, simulate a pre-etching cycle to the influence curve in fatigue safety life-span.

6., the Residual Damage degree of computation structure matrix after protection system lost efficacy.

7., in the pre-etching cycle to the influence curve in fatigue safety life-span being determined the point corresponding with the residue pilot time number of aircraft or the application plan of aircraft, thus determine the year injury tolerance of structural matrix under its corresponding flight rate or under its application plan, namely Residual Damage degree is obtained the calendar safe life of corrosion fatigue key component divided by year injury tolerance.

For stress corrosion key component, determine that the step of its matrix calendar safe life is as follows:

1., the position and the direction of check that the most easily produce stress corrosion crack in structure is determined.

2., by testpieces some groups are divided into, according to the position and the direction of check that the most easily produce stress corrosion crack, to the initial crack of the preset different length of the testpieces of difference group.

3. the stress corrosion (cracking) test of each group of testpieces, is carried out.

4., the propagation law of identified sign corrosion cracking and Critical fracture length.

5. the dispersion coefficient under given fiduciary level and confidence level, is tried to achieve.

6., namely stress corrosion cracking (SCC) expansion time is obtained the calendar safe life of stress corrosion key component divided by dispersion coefficient.

Next, the defining method of the matrix calendar safe life of not loaded structure is introduced.

Determine the matrix calendar safe life of not loaded structure, specifically comprise the following steps:

1. the criterion of the disabler of not loaded structure, is determined.

2., carry out the corrosion test of testpieces, at set intervals extraction portion separating tests part measure the maximum corrosion depth of testpieces, obtain meeting under this abrasion cycle the matrix maximum corrosion depth that given fiduciary level and confidence level require.

3., by meeting the matrix maximum corrosion depth that given fiduciary level and confidence level require under different abrasion cycle comprehensively analyzing, obtaining abrasion cycle when structure reaches failure criteria, the described abrasion cycle i.e. matrix calendar safe life of not loaded structure.

Then, the last time after overhaul, head is turned over rear protecting system calendar safe life Y ₂with structural matrix calendar safe life Y _cbe added, then with the last overhaul of structure after by the military service cycle Y remaining pilot time number or the number of times that rises and falls and determine _r' compare:

If Y ₂+ Y _c> Y _r', illustrate that structural shielding system or matrix not yet lost efficacy, then by Y when fatigue safety life-span to the longevity _r' be defined as remaining the military service cycle;

If Y ₂+ Y _c≤ Y _r', the calendar safe life of description architecture matrix prior to structural fatigue safe life to the longevity, then by Y ₂+ Y _cbe defined as remaining the military service cycle.

Step 5: determine structure calendar safe life

Head is turned over the repairing time (Y that phase, all previous time between overhaul, residue military service cycle, all previous overhaul are used _s× N) be added, namely obtain aircaft configuration calendar safe life Y _t.Wherein, aircraft is Y in the single overhaul time of maintenance depot _s, being determined by the repairing level of maintenance depot, is known quantity.

Many Service Environment are got off the plane structural shielding system calendar safe life Y _tdetermination

Aircraft, in life-cycle military service process, be normally on active service in multiple area, and aircaft configuration is mainly subject to the corrosive attack of ground environment.As civil aircraft, normally in the multiple intercity conversion of institute's flight line; Military aircraft also often can be exchanged in different regions and use.Due to the difference of different regions corrosion environment, only composing with the equivalent environment in a certain area the structural shielding system calendar safe life determined is the protection system calendar life management that cannot be used for how regional military service aircraft.

It is relevant with the working strength of aircraft that the aircaft configuration head determined by structural fatigue safe life turns over brandish row hourage (rise and fall number of times), time between overhaul pilot time number (rise and fall number of times) of phase and time between overhaul and head, therefore, the aircaft configuration head determined by structural fatigue safe life turns over phase and time between overhaul by the impact of many Service Environment.And concerning protection system calendar safe life and structural matrix calendar safe life, their value and the erosion levels of environment closely related, different Service Environment correspond to different protection system calendar safe lifes and structural matrix calendar safe life.

Existing research shows, corrodes and obeys linear rule to the damaging action of material.On this basis, the determination of protection system calendar safe life under many Service Environment can be carried out by the computing method of linear cumulative damage, and then determine the calendar safe life of aircaft configuration under many Service Environment.

Determine the calendar safe life of aircaft configuration under many Service Environment, concrete steps are as follows:

Step 1: determine that head turns over the phase

First, determine that head turns over front protection system calendar safe life Y ₁, specifically comprise the steps:

(1), design and manufaction head turns over pre-structure protection system simulation test piece.

(2), the local environmental spectrum in the different area of being on active service of establishment.

(3) the calendar safe life of protection system under different Service Environment, is determined:

Determine that head turns over the calendar safe life of front protection system under each single Service Environment spectrum, the determination detailed process of the calendar safe life under single Service Environment spectrum comprises the following steps:

1. the failure criteria of structural simulation part protection system, is determined

First the head carried out under one group of pure fatigue turns over the torture test of pre-structure simulating piece, obtains the median fatigue life N that head turns over pre-structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out comprehensive analysis and providing the failure criteria that head turns over front protection system.

2. the fail data of protection system simulating piece, is obtained

When head turns over the damage characteristic that pre-structure simulating piece surfacecti proteon system occurs corresponding to failure criteria, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over front protection system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test.

3., determine that head turns over front protection system calendar safe life

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\α}}^{\′}}=\stackrel{\‾}{N}-k\·S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained.

(4), according to application plan prediction calendar safe life:

According to the computing method of linear cumulative damage, if the calendar safe life of protection system under a certain environment is T, aircraft employs t (t<T) under this Service Environment, then protection system is t/T in the amount of damage of this t; Aircraft continues to be on active service in other circumstances, amount of damage is accumulated, when the accumulated damage amount of protection system reaches 1, then think that protection system reaches the safe handling restriction of expection, the summation of now corresponding calendar life is regional protection system calendar safe life value of being on active service more.

Then, head is turned over front protection system calendar safe life Y ₁phase Y is turned over the structure head determined by the fatigue safety life-span ₁' compare:

If Y ₁> Y ₁', then by Y ₁' determine headed by turn over the phase;

If Y ₁≤ Y ₁', then by Y ₁the phase is turned over headed by determining.

Step 2: determine time between overhaul

First, determine that head turns over rear protecting system calendar safe life Y ₂, specifically comprise the steps:

(1), design and manufaction head turns over front and head and turns over rear structural shielding system simulation test piece.

(2), the local environmental spectrum in the different area of being on active service of establishment.

(3) the calendar safe life of protection system under different Service Environment, is determined:

Determine that head turns over the calendar safe life of rear protecting system under each single Service Environment spectrum with first before turning over, the determination detailed process of the calendar safe life under single Service Environment spectrum comprises the following steps:

1. the failure criteria of structural simulation part protection system, is determined

First turn over the torture test of rear structural simulation part with head before the head carried out under one group of pure fatigue turns over, obtain head and turn over the median fatigue life of pre-structure and the first median fatigue life turning over rear structure, the median fatigue life of structure is all counted and is made N ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, by the protection system damage characteristic of torture test life-span partially short testpieces in the testpieces of observing equivalence corrosion i, carry out comprehensive analyze provide head turn over before and first failure criteria of turning over rear protecting system.

2. the fail data of protection system simulating piece, is obtained

There is the damage characteristic corresponding to failure criteria in structural simulation part surfacecti proteon system after turning over head before head turns over, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, before contrast head turns over and head turn over rear protecting system failure criteria, from the testpieces finished torture test and not yet do torture test, obtain valid data respectively.

3., determine that head turns over front and head and turns over rear protecting system calendar safe life

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\&alpha;}}^{\&prime;}}=\stackrel{\&OverBar;}{N}-k\&CenterDot;S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained.

(4), according to application plan prediction calendar safe life:

According to the computing method of linear cumulative damage, if the calendar safe life of protection system under a certain Environmental Spectrum is T, aircraft is on active service in the area of its correspondence and is employed t (t<T), then protection system is t/T in the amount of damage of this t; When the accumulated damage amount of protection system reaches 1, then think that protection system reaches the safe handling restriction of expection, the summation of now corresponding calendar life is regional protection system calendar safe life value of being on active service more.

Then, head is turned over rear protecting system calendar safe life Y ₂with the time between overhaul Y before the arrival determined by the fatigue safety life-span i-th overhaul _i' compare:

If Y ₂> Y _i', then by Y _i' be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system is impaired, then by Y ₂be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system does not have impaired, and Y ₁> Y _i', then by Y _i' be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system does not have impaired, and Y ₁≤ Y _i', then by Y ₂be defined as time between overhaul.

Step 3: determine to repair number of times

Residue pilot time number and time between overhaul pilot time number are compared:

If the residue pilot time number of aircraft after certain overhaul is less than the time between overhaul pilot time number after this overhaul, then this time overhaul is the last overhaul of aircraft, i.e. N=i;

If the residue pilot time number of aircraft after certain overhaul is greater than the time between overhaul pilot time number after this overhaul, then aircraft can also be repaired next time, i.e. i=i+1, until the residue pilot time number after overhaul is less than the time between overhaul pilot time number after overhaul, now, statistics draws the repairing number of times of aircaft configuration.

Step 4: determine to remain the military service cycle

The last time after overhaul, head is turned over rear protecting system calendar safe life Y ₂with structural matrix calendar safe life Y _c(structural matrix calendar safe life Y _cdeterministic process before described, therefore do not repeat them here) be added, then with structure after last overhaul by the military service cycle Y remaining pilot time number or the number of times that rises and falls and determine _r' compare:

If Y ₂+ Y _c> Y _r', then by Y _r' be defined as remaining the military service cycle;

If Y ₂+ Y _c≤ Y _r', then by Y ₂+ Y _cbe defined as remaining the military service cycle.

Step 5: determine structure calendar safe life

The repairing time of head being turned over phase, all previous time between overhaul, residue military service cycle, all previous overhaul used is added, and namely obtains aircaft configuration calendar safe life.

Be defined as example with the calendar safe life of the wing crossbeam of certain type military aircraft under many Service Environment below, further illustrate method of the present invention.

In this instance analysis process, suppose that the flight rate of aircraft was equally distributed in 1 year, should appropriately adjust according to the flight planning of army in actual use procedure.

Design parameter and the application plan of structure are as follows:

The fatigue safety life-span of aircraft: 3000 pilot time.

The head determined by the fatigue safety life-span brandishes row hourage and time between overhaul pilot time number: head turned over for 1500 pilot time, time between overhaul 800 pilot time, and last overhaul is to the pilot time in fatigue safety life-span to longevity 700.

The military service application plan of aircraft:

The calendar safe life (year) of protection system under different Service Environment:

The abrasion cycle of the third ground environment is to structural matrix fatigue safety aging effects curve: N _99.9(T)=4650-670T ^0.54.

Overhaul required time: 0.25.

Step 1: determine that aircaft configuration head turns over the phase

(1) head that the calculating fatigue safety life-span is corresponding turns over the phase

The head determined according to the fatigue safety life-span brandishes the flight application plan of row hourage (1500 pilot time) and aircraft, calculating the head phase of turning over determined by the fatigue safety life-span is 11.33, aircraft is on active service 10 years in first before this, is on active service 1.33 in second.

(2) calculate head and turn over front protection system calendar safe life

Aircraft is on active service 10 years in first, and before the head of protection system under first ground environment turns over, calendar safe life is 12 years, then protection system first the injury tolerance of being on active service 10 years be 10/12, Residual Damage degree is: 1-10/12=1/6.

Before the head of protection system under second ground environment turns over, calendar safe life is 10 years, then protection system second the year injury tolerance of being on active service be 1/10, protection system is on active service to the calendar time lost efficacy in second is: (1/6)/(1/10)=1.67 year.

Therefore, head turns over front protection system calendar safe life is 10+1.67=11.67.

(3) determine that aircaft configuration head turns over the phase

Be greater than the head determined by the fatigue safety life-span turn over the phase (11.33) because head turns over front protection system calendar safe life (11.67), the head phase of turning over of aircaft configuration is taken as 11.33; Arrive aircraft when structure head turns over the phase to be on active service in second, by flight use 1500 pilot time.

Step 2: the time between overhaul determining aircaft configuration

(1) time between overhaul that the calculating fatigue safety life-span is corresponding

The time between overhaul pilot time number (800 pilot time) determined according to the fatigue safety life-span and the flight application plan of aircraft, time between overhaul before the arrival second time overhaul determined by the fatigue safety life-span is 6.67, aircraft is on active service 5.67 in second during this time between overhaul, is on active service 1 year on the third ground.

(2) the protection system calendar safe life before second time overhaul is calculated

It is very close that the head turning over front protection system calendar safe life and aircaft configuration due to head turns over the phase, and can think that the unrepairable protection system of internal layer sustains damage, the protection system after head turns over can not return to factory state.Rear protecting system calendar safe life should be turned over the head under the third ground environment and calculate according to second.

Be on active service 5.67 in second after aircraft head turns over, after the head of protection system under second ground environment turns over, calendar safe life is 7 years, then protection system second the injury tolerance of being on active service 5.67 be 5.67/7, Residual Damage degree is: 1-5.67/7=1.33/7.

After the head of protection system under the third ground environment turns over, calendar safe life is 4 years, the year injury tolerance that then protection system is on active service on the third ground is 1/4, and protection system in the third ground military service to the calendar time lost efficacy is: (1.33/7)/(1/4)=0.76 year.

Therefore, before second time overhaul, protection system calendar safe life is 5.67+0.76=6.43.

(3) time between overhaul of aircaft configuration is determined

Because protection system calendar safe life (6.43) before second time overhaul is less than the time between overhaul (6.67) determined by the fatigue safety life-span, the time-between-overhaul life of aircaft configuration before second time overhaul is taken as 6.43; During the second time overhaul of arrival structure, aircraft is on active service on the third ground, and cumulative flight was used for 2276 pilot time by aircraft.

Step 3: the calendar safe life determining aircaft configuration

The residue pilot time number of aircaft configuration is the 3000-2276=724 pilot time, be less than the time between overhaul pilot time number (800 pilot time) determined by the fatigue safety life-span, therefore, aircaft configuration carries out the requirement that twice overhaul can reach the fatigue safety life-span.But from the angle of calendar safe life, also need to judge the safe active time of the calendar of structure.

(1) the protection system calendar safe life after second time overhaul is determined

The head determined under the third ground environment due to protection system turns over rear protecting system calendar safe life (4 years) and is less than the time limit (7.24) having flown to remain pilot time number, and the protection system calendar safe life therefore got after second time overhaul is 4 years.

(2) the matrix calendar safe life of structure is determined

In the protection system valid period, the total time flown number of aircraft is 2276+100 × 4=2676 pilot time, and the accumulated damage of structural matrix is 2676/3000, and Residual Damage degree is 324/3000.

According to the calendar safe life computing formula (N of structural matrix on the third ground _99.9(T)=4650-670T ^0.54) and application plan (100 pilot time, the i.e. N of aircraft _99.9(T)=100T), try to achieve T=16.3.This means that aircaft configuration matrix is not when having protective layer to protect, from factory state with the flight of the intensity at annual 100 pilot time, matrix calendar safe life is 16.3 years.

Therefore, consider the accumulated damage of protective layer valid period structural matrix, after protective layer loses efficacy, the calendar safe life of structural matrix was 16.3 × 324/3000=1.76.

(3) the residue calendar safe life of aircaft configuration after second time overhaul is determined

Because second time overhaul rear protecting system calendar safe life and structural matrix calendar safe life sum (5.76) were less than by the military service cycle (7 years) remaining pilot time number and determine, therefore the residue calendar safe life of aircaft configuration after second time overhaul is taken as 5.76.

(4) the calendar safe life of aircaft configuration is determined

Structure head is turned over the phase (11.33), structure time between overhaul (6.43), the repairing time (0.5 year) of residue calendar safe life (5.76) and twice overhaul is added, the calendar safe life obtaining structure is 24.02 years; Aircaft configuration is accumulation flight use 2852 pilot time when arriving calendar safe life, still has the fatigue safety life-span at 148 pilot time not use.

If carry out third time overhaul to aircraft, will be uneconomic.In order to use aircraft economically, utilize again the fatigue safety life-span of structure fully, two kinds of processing modes can be had: one is aircraft is carried out fatigue lengthen the life, after protection system lost efficacy, carry out the third time overhaul of aircaft configuration, to share the financial cost of third time overhaul; Two is change of flight plans, increases the flight rate of aircraft on the third ground, especially at the flight rate of protection system non-paralysis period, can be finished the residue pilot time number of aircraft in advance.

As can be seen here, method of the present invention is used can to determine the calendar safe life of aircaft configuration.By the aircaft configuration calendar safe life determined, the safe service life of aircaft configuration can be determined comparatively accurately, to ensureing that the use safety of aircaft configuration is significant.

In addition, by the aircaft configuration calendar safe life determined, can also provide foundation for reasonably formulating aircraft utilization plan, to giving full play to Aircraft Structural Life potentiality, the life-span management level promoting aircaft configuration is significant.

It should be noted that, above-described embodiment does not limit the present invention in any form, the technical scheme that the mode that all employings are equal to replacement or equivalent transformation obtains, and all drops in protection scope of the present invention.

Claims (6)

1. the defining method of aircaft configuration calendar safe life, is characterized in that, comprises the following steps:

Step 1: determine that head turns over the phase

Head is turned over front protection system calendar safe life Y ₁phase Y is turned over the structure head determined by the fatigue safety life-span ₁' compare:

If Y ₁> Y ₁', then by Y ₁' determine headed by turn over the phase;

If Y ₁≤ Y ₁', then by Y ₁the phase is turned over headed by determining;

Step 2: determine time between overhaul

Head is turned over rear protecting system calendar safe life Y ₂with the time between overhaul Y before the arrival determined by the fatigue safety life-span i-th overhaul _i' compare:

If Y ₂> Y _i', then by Y _i' be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system is impaired, then by Y ₂be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system does not have impaired, and Y ₁> Y _i', then by Y _i' be defined as time between overhaul;

If Y ₂≤ Y _i', and during overhaul, internal layer unrepairable protection system does not have impaired, and Y ₁≤ Y _i', then by Y ₂be defined as time between overhaul;

Step 3: determine to repair number of times

Residue pilot time number and time between overhaul pilot time number are compared:

If the residue pilot time number of aircraft after certain overhaul is less than the time between overhaul pilot time number after this overhaul, then this time overhaul is the last overhaul of aircraft;

If the residue pilot time number of aircraft after certain overhaul is greater than the time between overhaul pilot time number after this overhaul, then aircraft can also be repaired next time, until the residue pilot time number after overhaul is less than the time between overhaul pilot time number after overhaul, now, statistics draws the repairing number of times of aircaft configuration;

Step 4: determine to remain the military service cycle

The last time after overhaul, head is turned over rear protecting system calendar safe life Y ₂with structural matrix calendar safe life Y _cbe added, then with structure after last overhaul by the military service cycle Y remaining pilot time number or the number of times that rises and falls and determine _r' compare:

If Y ₂+ Y _c> Y _r', then by Y _r' be defined as remaining the military service cycle;

If Y ₂+ Y _c≤ Y _r', then by Y ₂+ Y _cbe defined as remaining the military service cycle;

Step 5: determine structure calendar safe life

The repairing time of head being turned over phase, all previous time between overhaul, residue military service cycle, all previous overhaul used is added, and namely obtains aircaft configuration calendar safe life.

2. the defining method of aircaft configuration calendar safe life according to claim 1, is characterized in that, under single Service Environment, determines that head turns over front protection system calendar safe life Y ₁process comprise the following steps:

(1), design and manufaction head turn over before protection system simulation test piece;

(2), protection system Environmental Spectrum is worked out;

(3) failure criteria of simulating piece protection system, is determined

First the head carried out under one group of pure fatigue turns over the torture test of pre-structure simulating piece, obtains the median fatigue life N of structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out the failure criteria that comprehensive analysis provides protection system;

(4) fail data of protection system simulating piece, is obtained

When head turns over the damage characteristic that pre-structure simulating piece surfacecti proteon system occurs corresponding to failure criteria, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over front protection system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test;

(5) reliability of, analytical test data, protection system calendar safe life is determined

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\&alpha;}}^{\&prime;}}=\stackrel{\&OverBar;}{N}-k\&CenterDot;S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained.

3. the defining method of aircaft configuration calendar safe life according to claim 1, is characterized in that, under many Service Environment, determines that head turns over front protection system calendar safe life Y ₁process comprise the following steps:

(1), design and manufaction head turns over pre-structure protection system simulation test piece;

(2), the local environmental spectrum in the different area of being on active service of establishment;

(3) the calendar safe life of protection system under different Service Environment, is determined

Determine that head turns over the calendar safe life of front protection system under each single Service Environment spectrum, the determination detailed process of the calendar safe life under single Service Environment spectrum comprises the following steps:

1. the failure criteria of structural simulation part protection system, is determined

First the head carried out under one group of pure fatigue turns over the torture test of pre-structure simulating piece, obtains the median fatigue life N that head turns over pre-structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out comprehensive analysis and providing the failure criteria that head turns over front protection system;

2. the fail data of protection system simulating piece, is obtained

When head turns over the damage characteristic that pre-structure simulating piece surfacecti proteon system occurs corresponding to failure criteria, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over front protection system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test;

3., determine that head turns over front protection system calendar safe life

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h(1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\&alpha;}}^{\&prime;}}=\stackrel{\&OverBar;}{N}-k\&CenterDot;S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained;

(4), according to application plan prediction calendar safe life

According to the computing method of linear cumulative damage, when the accumulated damage amount of protection system reaches 1, then think that protection system reaches the safe handling restriction of expection, the summation of now corresponding calendar life is regional protection system calendar safe life value of being on active service more.

4. the defining method of aircaft configuration calendar safe life according to claim 1, is characterized in that, under single Service Environment, determines that head turns over rear protecting system calendar safe life Y ₂process comprise the following steps:

(1), design and manufaction head turn over after protection system simulation test piece;

(2), protection system Environmental Spectrum is worked out;

(3) failure criteria of simulating piece protection system, is determined

First the head carried out under one group of pure fatigue turns over the torture test of rear structural simulation part, obtains the median fatigue life N of structure ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, corroding the protection system damage characteristic of the testpieces that the torture test life-span is partially short in the testpieces of i by observing equivalence, carrying out the failure criteria that comprehensive analysis provides protection system;

(4) fail data of protection system simulating piece, is obtained

There is the damage characteristic corresponding to failure criteria in structural simulation part surfacecti proteon system after head turns over, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, contrast head turns over rear protecting system failure criteria, obtains valid data respectively from the testpieces finished torture test and not yet do torture test;

(5) protection system calendar safe life, is determined

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\&alpha;}}^{\&prime;}}=\stackrel{\&OverBar;}{N}-k\&CenterDot;S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained.

5. the defining method of aircaft configuration calendar safe life according to claim 1, is characterized in that, under many Service Environment, determines that head turns over rear protecting system calendar safe life Y ₂process comprise the following steps:

(1), design and manufaction head turns over front and head and turns over rear structural shielding system simulation test piece;

(2), the local environmental spectrum in the different area of being on active service of establishment;

(3) the calendar safe life of protection system under different Service Environment, is determined

Determine that head turns over the calendar safe life of rear protecting system under each single Service Environment spectrum with first before turning over, the determination detailed process of the calendar safe life under single Service Environment spectrum comprises the following steps:

1. the failure criteria of structural simulation part protection system, is determined

First turn over the torture test of rear structural simulation part with head before the head carried out under one group of pure fatigue turns over, obtain head and turn over the median fatigue life of pre-structure and the first median fatigue life turning over rear structure, the median fatigue life of structure is all counted and is made N ₀; Keep fatigue loading condition constant, carry out again respectively equivalent pre-etching 1 year, 2 years, 3 years ... n group prior-corroded fatigue test after n, obtains the median fatigue life N of each group respectively ₁, N ₂, N ₃..., N _n; If from 1 year, N _iwith N ₀compare and there is significant difference, then think the impact receiving fatigue lifetime of some testpieces in 1 year protection system damage, by the protection system damage characteristic of torture test life-span partially short testpieces in the testpieces of observing equivalence corrosion i, carry out comprehensive analyze provide head turn over before and first failure criteria of turning over rear protecting system;

2. the fail data of protection system simulating piece, is obtained

There is the damage characteristic corresponding to failure criteria in structural simulation part surfacecti proteon system after turning over head before head turns over, namely think that the surfacecti proteon system of this part simulating piece reaches calendar life in limited time in this equivalence corrosion in year, before contrast head turns over and head turn over rear protecting system failure criteria, from the testpieces finished torture test and not yet do torture test, obtain valid data respectively;

3., determine that head turns over front and head and turns over rear protecting system calendar safe life

The fiduciary level of selecting structure surfacecti proteon system is α, suppose that practical structures is h times of testpieces key position surface area at the surface area of key position, when carrying out the calendar safe life analysis of practical structures surfacecti proteon system with test figure, the fiduciary level α ' chosen is:

α’＝(h+α-1)/h (1)

The protection system calendar safe life meeting given fiduciary level α ' and confidence level is determined according to formula (2):

$N_{{\mathrm{\&alpha;}}^{\&prime;}}=\stackrel{\&OverBar;}{N}-k\&CenterDot;S---\left(2\right)$

In formula (2), N _{α '}for the calendar safe life of protection system, for testing the mean value of the calendar life obtained, k is for meeting the monolateral tolerance factor of fiduciary level α ' and given confidence level, and S is the standard deviation testing the calendar life obtained;

(4), according to application plan prediction calendar safe life

According to the computing method of linear cumulative damage, when the accumulated damage amount of protection system reaches 1, then think that protection system reaches the safe handling restriction of expection, the summation of now corresponding calendar life is regional protection system calendar safe life value of being on active service more.

6. the defining method of aircaft configuration calendar safe life according to claim 1, is characterized in that, determines structural matrix calendar safe life Y _cprocess comprise the following steps:

(1) structural matrix simulation test piece, is manufactured and designed;

(2), programming structure local matrix Environmental Spectrum and structural loads spectrum;

(3) the matrix calendar safe life of aircaft configuration, is determined

For the corrosion fatigue key component in loaded structure, determine that the step of its matrix calendar safe life is as follows:

1. the fatigue safety life-span of overall aircraft, is determined;

2., by testpieces be divided into some groups, often organize testpieces under accelerated environment spectrum, experience the different pre-etching cycles;

3., after pre-etching, under the loading spectrum of establishment, torture test is carried out to fracture;

4., under selected fiduciary level and confidence level, the safe life often organizing prior-corroded fatigue testpieces is calculated;

5., by the prior-corroded fatigue safe life often organizing testpieces carry out matching, simulate a pre-etching cycle to the influence curve in fatigue safety life-span;

6., the Residual Damage degree of computation structure matrix after protection system lost efficacy;

7., in the pre-etching cycle to the influence curve in fatigue safety life-span being determined the point corresponding with the residue pilot time number of aircraft or the application plan of aircraft, thus determine the year injury tolerance of structural matrix under its corresponding flight rate or under its application plan, namely Residual Damage degree is obtained the calendar safe life of corrosion fatigue key component divided by year injury tolerance;

For the stress corrosion key component in loaded structure, determine that the step of its matrix calendar safe life is as follows:

1., the position and the direction of check that the most easily produce stress corrosion crack in structure is determined;

2., by testpieces some groups are divided into, according to the position and the direction of check that the most easily produce stress corrosion crack, to the initial crack of the preset different length of the testpieces of difference group;

3. the stress corrosion (cracking) test of each group of testpieces, is carried out;

4., the propagation law of identified sign corrosion cracking and Critical fracture length;

5. the dispersion coefficient under given fiduciary level and confidence level, is tried to achieve;

6., namely stress corrosion cracking (SCC) expansion time is obtained the calendar safe life of stress corrosion key component divided by dispersion coefficient;

For not loaded structure, determine that the step of its matrix calendar safe life is as follows:

1. the criterion of the disabler of not loaded structure, is determined;

2., carry out the corrosion test of testpieces, at set intervals extraction portion separating tests part measure the maximum corrosion depth of testpieces, obtain meeting under this abrasion cycle the matrix maximum corrosion depth that given fiduciary level and confidence level require;

3., by meeting the matrix maximum corrosion depth that given fiduciary level and confidence level require under different abrasion cycle comprehensively analyzing, obtaining abrasion cycle when structure reaches failure criteria, the described abrasion cycle i.e. matrix calendar safe life of not loaded structure.