CN105760577B - A kind of evaluation method containing uncertain metal structure sound and vibration fatigue life - Google Patents
A kind of evaluation method containing uncertain metal structure sound and vibration fatigue life Download PDFInfo
- Publication number
- CN105760577B CN105760577B CN201610058998.XA CN201610058998A CN105760577B CN 105760577 B CN105760577 B CN 105760577B CN 201610058998 A CN201610058998 A CN 201610058998A CN 105760577 B CN105760577 B CN 105760577B
- Authority
- CN
- China
- Prior art keywords
- stress
- uncertain
- frequency
- fatigue life
- value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 16
- 239000002184 metal Substances 0.000 title claims abstract description 16
- 238000011156 evaluation Methods 0.000 title claims abstract description 12
- 238000000034 method Methods 0.000 claims abstract description 31
- 238000004458 analytical method Methods 0.000 claims abstract description 24
- 230000003595 spectral effect Effects 0.000 claims abstract description 18
- 230000004044 response Effects 0.000 claims abstract description 17
- 239000000463 material Substances 0.000 claims abstract description 12
- 230000006378 damage Effects 0.000 claims abstract description 10
- 230000000750 progressive effect Effects 0.000 claims abstract description 4
- 239000013598 vector Substances 0.000 claims description 16
- 239000007769 metal material Substances 0.000 claims description 13
- 238000001228 spectrum Methods 0.000 claims description 12
- 230000008569 process Effects 0.000 claims description 8
- 230000003938 response to stress Effects 0.000 claims description 8
- 238000005311 autocorrelation function Methods 0.000 claims description 7
- 238000012546 transfer Methods 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 238000005259 measurement Methods 0.000 claims description 5
- 208000027418 Wounds and injury Diseases 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 claims description 3
- 230000006735 deficit Effects 0.000 claims description 3
- 239000000284 extract Substances 0.000 claims description 3
- 208000014674 injury Diseases 0.000 claims description 3
- 238000013459 approach Methods 0.000 claims description 2
- 230000008859 change Effects 0.000 claims description 2
- 230000001788 irregular Effects 0.000 claims description 2
- 238000004088 simulation Methods 0.000 claims description 2
- 230000017260 vegetative to reproductive phase transition of meristem Effects 0.000 claims description 2
- 241000208340 Araliaceae Species 0.000 claims 1
- 235000005035 Panax pseudoginseng ssp. pseudoginseng Nutrition 0.000 claims 1
- 235000003140 Panax quinquefolius Nutrition 0.000 claims 1
- 125000004122 cyclic group Chemical group 0.000 claims 1
- 230000007423 decrease Effects 0.000 claims 1
- 235000008434 ginseng Nutrition 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 5
- 230000005284 excitation Effects 0.000 abstract description 5
- 238000006073 displacement reaction Methods 0.000 abstract description 3
- 230000001902 propagating effect Effects 0.000 abstract 1
- 239000011159 matrix material Substances 0.000 description 12
- 238000005316 response function Methods 0.000 description 6
- 238000009826 distribution Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 4
- 208000037656 Respiratory Sounds Diseases 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000013016 damping Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 229910001008 7075 aluminium alloy Inorganic materials 0.000 description 1
- 206010014020 Ear pain Diseases 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000009661 fatigue test Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000017105 transposition Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/17—Mechanical parametric or variational design
Landscapes
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Pure & Applied Mathematics (AREA)
- Mathematical Optimization (AREA)
- Mathematical Analysis (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Computational Mathematics (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a kind of evaluation methods containing uncertain metal structure sound and vibration fatigue life.This method initially sets up the finite element analysis model of metal structure, considers the uncertain effect of material and structural property parameter under the conditions of finite sample, rings analysis theories based on frequency and obtains system transter；Then according to random noise load the characteristics of, for the steady ergodic random noise load of exemplary wideband, each key event displacement is obtained with quadratic sum evolution (SRSS) method, the Root mean square response and stress power spectral density function (PSD) of stress, in conjunction with the uncertain analysis method for propagating second order Taylor series expansion method and frequency domain internal vibration fatigue of Dirlik model and section, establish the relationship between rain stream amplitude probability density function and power spectral density function, finally the sound and vibration fatigue life interval range containing uncertain metal structure is obtained using the linear progressive damage theory of Miner.The present invention has fully considered the dispersibility of structure and material parameter when calculating the structural life-time by typical random noise excitation, therefore obtained fatigue life is more reasonable.
Description
Technical field
The present invention relates to metal structure noise and vibration fatigue technical fields, in particular to consider uncertain effect flowering structure
For the dynamic response and acoustic fatigue life estimation method of random noise load.Suitable for knots various under typical complex acoustic loads
The acoustic fatigue service life of structure type is efficiently predicted, provides help for the design of engineering acoustic resistive fatigue structure.
Background technique
Acoustic loads are a kind of spatial distributions to the effect essence of structure, with certain frequency distribution character dynamic with
Machine pressure loading.When sound pressure level magnitude is more than 140dB, it can generate certain distributed stress response in structure, especially
When the dynamic characteristic for the structure that the frequency distribution characteristic of noise is acted on it is mutually coupled, structure will generate significant stress
Response.Acoustic fatigue belongs to high all low stress problems, and under the long duration of action of this dynamic stress, the stress collection of structure, which neutralizes, to be lacked
Concave portion position will form fatigue crack, in engineering when crack nucleation and expand to the stage that can examine length after produces fatigue
Crack initiation life is the sound and vibration fatigue life to be studied.
Aircraft is in engine jet, aerodynamic force and wall surface coupling, body self structure work during military service
The complicated noise of generations such as vibrate.As the raising of vehicle flight speeds, the increase of power device thrust and operation are wanted
The improvement of performance is asked, the various noise magnitudes generated in aircraft operation constantly increase.Practice have shown that whether military aircraft
Or various types of acoustic fatigue breakoff phenomenons all can usually occur in use in civil aircraft.It is wherein most of to show themselves in that respectively
Kind aerofoil covering and fuselage side skin crackle, rib and fuselage ring frame crackle, air intake duct inside panel crackle, tail are in sedimentation exhalation
Under various destructions.There are many limitations for traditional acoustic fatigue life estimate, such as: it is only examined when considering dynamic stress effect
Low order frequency is considered, some only considered first natural frequency, and effect caused by the load high to the wide energy of frequency distribution has one
Determine error；Designer need to understand whether material used in object and structural shape are identical as existing curve in Preliminary design,
It is identical, the acoustic fatigue test curve of specific structural shape and material can be quoted after obtaining root-mean-square value stress to obtain the longevity
Life, but it is not identical, it needs to re-start design of Structural Parameters, comes equivalent conversion and result experiential modification according to existing curve,
This measure heavy workload and precision is low；The root-mean-square value life curve of specific structure and material inherently lacks very much, existing at present
Quantity is few, needs to obtain a large amount of test data and supports.
In addition, initial imperfection caused by manufacturing processing technic and material heterogeneity and damage are inevitable, and not
Come during long service to continue to develop in inside configuration, sprawling, propagate, drastically influences the mechanical behavior of structure and using peace
Entirely.Establish uncertain characterization technique based on non-probability theory frame, uncertain metal structure sound and vibration fatigue life
Estimating techniques have significant realistic meaning.
Summary of the invention
The technical problem to be solved by the present invention is overcoming the deficiencies of the prior art and provide a kind of for containing uncertain gold
Belong to the evaluation method of structure sound and vibration fatigue life.The present invention fully consider in Practical Project problem it is generally existing it is uncertain because
Element characterizes Uncertainty in non-probability interval method, introduces indeterminacy section communication theory, and obtained design result more accords with
Truth is closed, engineering adaptability is stronger.
The technical solution adopted by the present invention are as follows: a kind of evaluation method containing uncertain metal structure sound and vibration fatigue life,
Realize that steps are as follows:
Step 1: being used according to flight mission profile time data and state acoustic load Measurement bandwidth sound pressure levelIt is converted into the frequency spectrum load of random noise, wherein L=Lb- 10lg (Δ f), P0=2 × 10-5Pa is
Reference sound pressure, LbFor bandwidth sound pressure level, Δ f is frequency bandwidth, and G (f) is the noise power spectral density value after conversion；
Step 2: introducing section vector x ∈ xI=[E, a, b] rationally quantifies the structure under the conditions of poor information, a small number of evidences
Uncertain parameter, wherein E is metal material elasticity modulus, and a and b respectively indicate the geometric parameter of structure different parts.Then containing knot
The uncertainty of structure parameter can indicate are as follows: Represent the value of parameter
The upper bound,x=[E,a,b]=[Ec-Er,ac-ar,bc-br],xThe value lower bound of parameter is represented, wherein subscript c represents central value, on
Mark r represents radius；
Step 3: establishing the geometrical model of interested structure, the type of attachment of component is analyzed, classifying rationally grid applies side
Boundary's condition forms finite element analysis model.Unit uniform surface pressure loading is loaded in finite element analysis software, wherein load
Frequency range is identical as the frequency range of the resulting acoustic loads of the first step, extracts after carrying out frequency response analysis to model
The stress transfer function of each node of structure；
Step 4: reading third step in MSC.Patran random vibration module using quadratic sum evolution (SRSS) method
Obtained stress transfer function, and apply the resulting pectrum noise load of the first step and obtain the stress power spectrum density of node
(PSD) curve, wherein random vibration analysis output file further includes the power spectral density of frequency response, auto-correlation function, every list
The zero crossing number in the positive slope direction of position time and the RMS value of stress response；
Step 5: it is to change at random that the typical feature of random noise, which is pressure time course amplitude, that is, it is irregular
The form that non-decaying cannot use analytical function to express, the variation range of this kind of noise frequency is wide, spectrum until very high-frequency all
It is continuous.In conjunction with the Dirlik model and interval propagation analysis method of exemplary wideband random process, answered with obtained in the previous step
Power PSD curve is input, obtains uncertain Variable Transmission using the Taylor series expansion method in non-probability interval procedural theory
Stress rain stream amplitude probability density function (PDF) variation range of each key event afterwards；
Step 6: for continuously distributed stress state, by time T inherent strain range (Si,Si+ΔSi) in stress follow
Ring number is expressed as ni=vTp (Si)ΔSi.V in formula indicates the stress-number of cycles in the unit time, by peak dot number per second
E [P] decision, i.e. v=E [P], p (Si) expression stress level level be SiWhen amplitude probability density functional value, Δ SiIt is answered to be small
Power grade variation range；
Step 7: selecting the S-N curve of corresponding metal material in MSC.Fatigue, expression formula is N (Si)=K/Sm,
Using the linear progressive damage theory D=∑ D of Mineri=∑ ni/Ni, component is obtained as overall impairment degree D=1, and tired break occurs
Bad fatigue life time are as follows:
Wherein, K and m is material constant, and N is metal material cycle-index, and D is injury tolerance.Component hair is finally calculated
Time lifetime cloud charts when raw fatigue rupture.Analysis theories, which are propagated, according to non-probability interval obtains the life time model of component
It encloses.
Further, bounded-but-unknown uncertainty parameter vector x can be indicated in the second step are as follows:
Wherein, xc=(Ec,ac,bc), xr=(Er,ar,br), e ∈ Ξ3, Ξ3All elements are defined as in [- 1,1]
3 dimensional vector set, symbol "×" is defined as two each corresponding elements of vector, and product is still 3 dimensional vectors.
Further, the Dirlik model applied in the 5th step is suitable for the simulation of exemplary wideband random process, right
In narrowband or have its result accuracy of the random process of spike (i.e. pulse amplitude) characteristic for reference.
Further, non-probability interval propagates analysis method and uses second order Taylor series expansion in the 5th step
The bound of method, response section may be expressed as:
Wherein,WithΨi Indicate that i Uncertainty takes bound respectivelyWithx iResponse results bound, Ψi
(xc) indicate that uncertain variables take intermediate value xcWhen structure is interested measures response,Indicate Ψi(xc) at i-th
The first derivative expansion value at uncertain parameter midpoint,Indicate two at uncertain variables interval midpoint
Rank expansion, Δ xiWith Δ xjRespectively indicate the section radius of i-th and j-th uncertain variables.
The advantages of the present invention over the prior art are that: the present invention provides the new approaches of acoustic fatigue life estimate, more
It mends and the perfect limitation of traditional theory.The method of tradition estimation acoustic fatigue can only be directed to specific structure type, the method
Arbitrary structures form can be calculated；Conventional method needs a root-mean-square value stress- life, and the method only needs classic fatigue
Life curve.When considering material and structure disperses, this method requires no knowledge about the form of probability of uncertain parameter, only
Need to know that the boundary up and down of metal material and geometrical parameters can be solved easily containing uncertain metal material
The acoustic fatigue service life interval range of arbitrary structures form, it is more convenient reliable in terms of Practical.
Detailed description of the invention
Fig. 1 is the present invention for the evaluation method flow chart containing uncertain metal structure sound and vibration fatigue life；
Fig. 2 is the flow diagram for the finite element analysis software that the present invention uses；
Fig. 3 is that the present invention is simplified for aircraft cavity structure and applies the finite element model after boundary condition；
Fig. 4 is the power spectral density function schematic diagram for the key event that model is calculated in the present invention；
Fig. 5 is S-N curve of the present invention for the reference of 7075-HV-T6 metal material；
Fig. 6 is the metal material sound and vibration FATIGUE LIFE DISTRIBUTION cloud atlas that the present invention is calculated；
Fig. 7 is the node minimum life interval range that the present invention obtains the structure containing uncertain parameter.
Specific embodiment
With reference to the accompanying drawing and specific embodiment further illustrates the present invention.
As shown in Figure 1, the invention proposes a kind of evaluation method containing uncertain metal structure sound and vibration fatigue life, packet
Include following steps:
(1) according to the regulation in general norm, only when airplane structural parts bear the 130dB acoustic pressure more than human ear pain domain
Acoustic fatigue problem is considered when grade.According to flight mission profile time data and state acoustic load Measurement bandwidth sound pressure level (octave
Bandwidth or third-octave bandwidth etc.), it usesIt is converted into the frequency spectrum load of random noise, wherein L
=Lb- 10lg (Δ f), P0=2 × 10-5Pa is reference sound pressure, LbFor bandwidth sound pressure level, Δ f is frequency bandwidth, and G (f) is conversion
Noise power spectral density value afterwards.
Table 1 is International standardization octave frequency meter cited in the present invention, illustrates International Organization for standardization's suggestion
Frequency meter.The noise bandwidth of any centre frequency, which can table look-up, to be obtained, according to the bandwidth sound pressure level of actual measurement, according to above-mentioned conversion formula
Then its corresponding power spectral density.Such as the sound field for 100Hz centre frequency, bandwidth 22.9Hz, if the bandwidth of actual measurement
Sound pressure level is 127dB, then the power spectral density after sound field is converted is 87.544Pa2/Hz.If the measured value time-domain signal of noise field
Then it is changed into spectrum signal by welfare leaf transformation to be analyzed again.
Table 1
| Lower frequency limit | Centre frequency | Upper limiting frequency | Lower frequency limit | Centre frequency | Upper limiting frequency |
| 22.4 | 25 | 28.2 | 707.9 | 800 | 891.3 |
| 28.2 | 31.5 | 35.5 | 891.3 | 1000 | 1122 |
| 35.5 | 40 | 44.7 | 1122 | 1250 | 1413 |
| 44.7 | 50 | 56.2 | 1413 | 1600 | 1778 |
| 56.2 | 63 | 70.8 | 1778 | 2000 | 2239 |
| 70.8 | 80 | 89.1 | 2239 | 2500 | 2818 |
| 89.1 | 100 | 112.2 | 2818 | 3150 | 3548 |
| 112.2 | 125 | 141.3 | 3548 | 4000 | 4467 |
| 141.3 | 160 | 177.8 | 4467 | 5000 | 5623 |
| 177.8 | 200 | 223.9 | 5623 | 6300 | 7079 |
| 223.9 | 250 | 281.8 | 7079 | 8000 | 8913 |
| 281.8 | 315 | 354.8 | 8913 | 10000 | 11220 |
| 354.8 | 400 | 446.7 | 11220 | 12500 | 14125 |
| 446.7 | 500 | 562.3 | 14125 | 16000 | 17783 |
| 562.3 | 630 | 707.9 | 17783 | 20000 | 22387 |
(2) section vector x ∈ x is introducedI=[E, a, b] rationally quantifies the not true of the structure under the conditions of poor information, a small number of evidences
Determine parameter, wherein E is metal material elasticity modulus, and a and b respectively indicate the geometric parameter of structure different parts.Then join containing structure
Several uncertainties can indicate are as follows: It represents in the value of parameter
Boundary,x=[E,a,b]=[Ec-Er, ac-ar, bc-br],xThe value lower bound of parameter is represented, wherein subscript c represents central value, subscript
R represents radius；Bounded-but-unknown uncertainty parameter vector x can be indicated are as follows:
Wherein, xc=(Ec, ac, bc), xr=(Er, ar, br), e ∈ Ξ3, Ξ3All elements are defined as in [- 1,1]
3 dimensional vector set, symbol "×" is defined as two each corresponding elements of vector, and product is still 3 dimensional vectors.
(3) finite element analysis model is formed, unit uniform surface pressure loading is loaded in MSC.Patran, wherein load
Frequency range is identical as the frequency range of the resulting acoustic loads of the first step, extracts after carrying out frequency response analysis to model
The frequency response function of each node of structure, herein referred to as stress transfer function.
(4) quadratic sum evolution (SRSS) method is applied, the stress transfer that (3) step obtains is read in random vibration module
Function, and apply the resulting pectrum noise load of the first step and obtain stress power spectrum density (PSD) curve of node, wherein at random
Vibration analysis output file further includes the zero crossing number of the auto-correlation function of frequency response, positive slope direction per unit time
And the RMS value of stress response.It is the theoretical procedure for calculating stress response mean-square value and power spectral density below.
Have for the multiple degrees of freedom problem by single-point-excitation:
Wherein M, C and K respectively represent the mass matrix damping matrix and stiffness matrix of system, and a (t) is that the displacement of system is rung
Function is answered, g (t) represents zero-mean stationary random process noise excitation, auto-correlation function Rgg(t), power spectral density function
For Sgg(f), q is load amplitude coefficient vector.Assuming that damping matrix is proportional damping, system is obtained using the formation addition method and is rung
It answers are as follows:
WhereinCoefficient is participated in for formation,For the jth rank formation of system, τ is tiny time interval, hj(τ) is
System transter obtained in third step.
There is the autocorrelation matrix of system response function according to the definition of auto-correlation function are as follows:
R in formulaaa(τ) and Rgg(τ) respectively indicates the auto-correlation function of response and excitation, and E expression takes stochastic variable
Value.Above formula shows that the autocorrelation matrix of response can be expressed as the double integral of the autocorrelation matrix of excitation.By Wiener relationship
Formula solves the autopower spectral density matrix that Fourier transform pairs is constituted with it:
Exp (- i2 π f τ) in the formula is rewritten into exp (- i2 π f τ1)·exp(-i2πfτ2)·exp(-i2πf(τ+τ1-
τ2)), then the company that the triple integral can be rewritten into following three integration types multiplies:
It is respectively constituted in Fu here with impulse response function and frequency response function, auto-correlation function and auto-power spectrum function
The conclusion of leaf transformation pair.Then the autopower spectral density matrix of available response are as follows:
For the many-degrees of freedom system response under general excitation, autopower spectral density matrix can be by load from function
Rate spectral density matrix Sqq(f) it is obtained with transfer function matrix H (f) by following formula:
Saa(f)=H*(f)Sqq(f)HT(f)
Wherein, H*(f) function that negative value obtains, H are taken for frequency in frequency response functionTIt (f) is the transposition square of frequency response function
Battle array.The stress power spectral density function of system is obtained after the displacement of system, stress response can according to said method be found out in summary
(PSD) curve.
(5) in conjunction with the Dirlik model of exemplary wideband random process and interval propagation analysis method, with obtained in the previous step
Stress PSD curve is input, is obtained using the vertex scheme in non-probability interval procedural theory each after uncertain Variable Transmission
Stress rain stream amplitude probability density function (PDF) variation range of key event.Dirlik model is expressed as follows:
Wherein, p (S) indicates stress probability density function, m0~m4For spectrum parameter byIt acquires, S table
Show stress level level, above formula illustrates the method that rain prevalence journey PDF is extracted directly from stress PSD.
Interval propagation analysis method uses second order Taylor series expansion method.Its bound for responding section can indicate
Are as follows:
Wherein,WithΨi Indicate that i Uncertainty takes bound respectivelyWithx iResponse results bound, xcIt indicates
The central value of uncertain variables, Ψi(xc) indicate that uncertain variables take intermediate value xcWhen structure is interested measures response,Indicate Ψi(xc) first derivative expansion value at i-th of uncertain parameter midpoint,
Indicate the second order expension at uncertain variables interval midpoint, Δ xiWith Δ xjRespectively indicate i-th and j-th uncertain variables
Section radius.
(6) for continuously distributed stress state, time T inherent strain range (Si,Si+ΔSi) in stress-number of cycles
N can be expressed as (frequency is equal to sum multiplied by probability)i=vTp (Si)ΔSi.V in formula indicates the stress in the unit time
Cycle-index is determined, i.e. v=E [P], p (S by peak dot number E [P] per secondi) expression stress level level be SiWhen amplitude probability
Density function values, Δ SiFor minimal stress grade variation range；
(7) the S-N curve of corresponding metal material is selected in MSC.Fatigue, expression formula is N (Si)=K/Sm, application
The linear progressive damage theory D=∑ D of Mineri=∑ ni/Ni, the destruction of component fatigue of voice is obtained as overall impairment degree D=1
Fatigue life time are as follows:
Wherein, K and m is material constant, and N is metal material cycle-index, and D is injury tolerance.It is illustrated in figure 2 in MSC system
The flow chart analyzed in column finite element software.Finally be calculated component occur fatigue rupture when time lifetime cloud charts with
Fatigue life logarithmic time range containing uncertain metal structure.
Embodiment:
The characteristics of in order to more fully understand the invention and its to the actual applicability of engineering, the present invention is established such as Fig. 3 institute
The aircraft cavity structure shown is simplified and applies the finite element model after boundary condition.The uncertain information of the model is E
=[67.45,74.55] GPa, calculates ssystem transfer function after unit face pressure varying with frequency is first loaded to model, then
Apply random noise load, table 2 gives applies the noise power spectral density load (unit after conversion on model in embodiment
Pa2/ Hz), obtain the preceding ten ranks intrinsic frequency of the structure, stress power spectral density function such as Fig. 4 institute of obtained node 373
Show, introducing material is 7075 aluminium alloys, and S-N curve is as shown in figure 5, finally be calculated service life cloud charts such as Fig. 6, application
Taylor series expansion interval propagation analysis method obtains logarithmic time life span such as Fig. 7.
Table 2
Table 3
In conclusion the invention proposes a kind of evaluation methods containing uncertain metal structure sound and vibration fatigue life.It is first
First, according to construction geometry, material the specific features of situations such as, analyze the type of attachment of component, and classifying rationally grid applies boundary
Condition forms finite element analysis model；Secondly, unascertained information is introduced in Frequency Response Analysis and random vibration analysis and frequency domain
With the Dirlik model of the amplitude information of spectrum parameter description scheme stress response, it is general that rain prevalence Cheng Yingli is extracted from stress PSD
Rate density function PDF；Finally, obtaining the vibration under random noise load with the second Taylor series analysis method of interval propagation theory
Dynamic fatigue life range.
Part of that present invention that are not described in detail belong to the well-known technology of those skilled in the art.
Claims (4)
1. a kind of evaluation method containing uncertain metal structure sound and vibration fatigue life, it is characterised in that realize that steps are as follows:
Step 1: being used according to flight mission profile time data and state acoustic load Measurement bandwidth sound pressure levelIt is converted into frequency spectrum load, wherein L=Lb- 10lg (Δ f), P0=2 × 10-5Pa is reference sound pressure,
LbFor bandwidth sound pressure level, Δ f is frequency bandwidth, and G (f) is the noise power spectral density value after conversion；
Step 2: introducing section vector x ∈ xI=[E, a, b] rationally quantifies poor information, a small number of uncertain ginsengs according to condition flowering structure
Number, wherein E is metal material elasticity modulus, and a and b respectively indicate the geometric parameter of structure, and the uncertainty containing structural parameters can
To indicate are as follows: The value upper bound of parameter is represented,x=[E,a,b]=
[Ec-Er,ac-ar,bc-br],xThe value lower bound of parameter is represented, wherein subscript c represents central value, and subscript r represents radius；
Step 3: establishing the geometrical model of interested structure, the type of attachment of component is analyzed, classifying rationally grid applies perimeter strip
Part forms finite element analysis model, unit uniform surface pressure loading is loaded in finite element analysis software, wherein the frequency of load
Variation range is identical as the frequency range of the resulting acoustic loads of the first step, extracts structure after carrying out frequency response analysis to model
The stress transfer function of each node；
Step 4: reading the stress that third step obtains in MSC.Patran random vibration module using quadratic sum evolution method
Transmission function, and apply the resulting pectrum noise load of the first step and obtain the stress power spectrum density curve of node, wherein at random
Vibration analysis output file further includes the zero crossing number of the auto-correlation function of frequency response, positive slope direction per unit time
And the mean-square value of stress response；
Step 5: it is to change at random, that is, irregular non-decline that the typical feature of random noise, which is pressure time course amplitude,
Subtract the form that cannot be expressed with analytical function, the variation range of this kind of noise frequency is wide, and spectrum is all to connect until very high-frequency
Continuous, in conjunction with the Dirlik model and interval propagation analysis method for simulating such exemplary wideband random process, obtained with previous step
Stress PSD curve be input, be introduced into Taylor expansion analytic approach in non-probability interval procedural theory obtain uncertain variables expansion
The stress rain stream amplitude probability density function variation range of each key event afterwards；
Step 6: for continuously distributed stress state, by time T inherent strain range (Si,Si+ΔSi) in Cyclic Stress time
Number is expressed as ni=vTp (Si)ΔSi, the v in formula indicates the stress-number of cycles in the unit time, by peak dot number E [P] per second
It determines, i.e. v=E [P], p (Si) expression stress level level be SiWhen amplitude probability density functional value, Δ SiFor minimal stress grade
Variation range；
Step 7: selecting the S-N curve of corresponding metal material in MSC.Fatigue, the feature expression of curve is N (Si)
=K/Sm, using the linear progressive damage theory D=∑ D of Mineri=∑ ni/Ni, component hair is obtained as overall impairment degree D=1
Fatigue life time that acoustic fatigue is destroyed are as follows:
Wherein, K and m is material constant, and N is metal material cycle-index, and D is injury tolerance, and it is broken that component fatigue is finally calculated
The time lifetime cloud charts and key event minimum life time range of bad when.
2. a kind of evaluation method containing uncertain metal structure sound and vibration fatigue life according to claim 1, feature
Be: bounded-but-unknown uncertainty parameter vector x can be indicated in the second step are as follows:
Wherein, xc=(Ec,ac,bc), xr=(Er,ar,br), e ∈ Ξ3, Ξ3Being defined as all elements includes 3 dimensions in [- 1,1]
Vector set, symbol "×" are defined as two each corresponding elements of vector, and product is still 3 dimensional vectors.
3. a kind of evaluation method containing uncertain metal structure sound and vibration fatigue life according to claim 1, feature
Be: the Dirlik model applied in the 5th step is suitable for the simulation of exemplary wideband random process, for narrowband or band
There is the random process of spike behavior its result accuracy for reference.
4. a kind of evaluation method containing uncertain metal structure sound and vibration fatigue life according to claim 1, feature
Be: non-probability interval propagates analysis method and uses second order Taylor series expansion method in the 5th step, responds section
Bound may be expressed as:
Wherein,WithΨi Indicate that i Uncertainty takes bound respectivelyWithx iResponse results bound, Ψi(xc) table
Show that uncertain variables take intermediate value xcWhen structure is interested measures response,Indicate Ψi(xc) uncertain at i-th
The first derivative expansion value at parameter midpoint,Indicate the second order exhibition at uncertain variables interval midpoint
It opens, Δ xiWith Δ xjRespectively indicate the section radius of i-th and j-th uncertain variables.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610058998.XA CN105760577B (en) | 2016-01-28 | 2016-01-28 | A kind of evaluation method containing uncertain metal structure sound and vibration fatigue life |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610058998.XA CN105760577B (en) | 2016-01-28 | 2016-01-28 | A kind of evaluation method containing uncertain metal structure sound and vibration fatigue life |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105760577A CN105760577A (en) | 2016-07-13 |
| CN105760577B true CN105760577B (en) | 2019-02-22 |
Family
ID=56342685
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610058998.XA Expired - Fee Related CN105760577B (en) | 2016-01-28 | 2016-01-28 | A kind of evaluation method containing uncertain metal structure sound and vibration fatigue life |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105760577B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108563850A (en) * | 2018-03-29 | 2018-09-21 | 内蒙古久和能源装备有限公司 | A kind of Random Response Analysis method and system considering material damping otherness |
| CN110765675B (en) * | 2018-07-24 | 2022-10-04 | 上汽通用五菱汽车股份有限公司 | Noise prediction method for automobile exhaust system |
| CN109239185A (en) * | 2018-08-24 | 2019-01-18 | 中国飞机强度研究所 | A kind of acoustic fatigue test part, design method, test method |
| CN109766613B (en) * | 2018-12-29 | 2020-10-27 | 西安交通大学 | Probability theory-based method for predicting bullet jump of thin-wall structure under thermal noise load |
| CN109857977B (en) * | 2019-03-08 | 2022-10-18 | 北京工业大学 | Frequency domain-based fatigue life calculation method under variable temperature vibration |
| CN111125971B (en) * | 2019-12-26 | 2022-03-25 | 北京航空航天大学 | Method for determining thrust uncertainty of air-breathing hypersonic aircraft |
| CN114047247B (en) * | 2021-11-10 | 2023-04-25 | 广东电网有限责任公司 | Method and device for detecting strain and hardness based on Barkhausen signals |
| CN114444336B (en) * | 2022-04-08 | 2022-07-26 | 杭州安脉盛智能技术有限公司 | New energy automobile motor service life estimation method and system based on information fusion |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102567633A (en) * | 2011-12-22 | 2012-07-11 | 上海交通大学 | Shore bridge structure wind vibration fatigue reliability forecasting method based on probability accumulated damage |
| CN104156500A (en) * | 2014-07-10 | 2014-11-19 | 东北大学 | Method for predicting material fatigue life |
| CN104833536A (en) * | 2014-02-12 | 2015-08-12 | 大连理工大学 | Structure fatigue life calculation method based on non-linear cumulative damage theory |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050072234A1 (en) * | 2003-05-20 | 2005-04-07 | Weidong Zhu | System and method for detecting structural damage |
-
2016
- 2016-01-28 CN CN201610058998.XA patent/CN105760577B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102567633A (en) * | 2011-12-22 | 2012-07-11 | 上海交通大学 | Shore bridge structure wind vibration fatigue reliability forecasting method based on probability accumulated damage |
| CN104833536A (en) * | 2014-02-12 | 2015-08-12 | 大连理工大学 | Structure fatigue life calculation method based on non-linear cumulative damage theory |
| CN104156500A (en) * | 2014-07-10 | 2014-11-19 | 东北大学 | Method for predicting material fatigue life |
Non-Patent Citations (2)
| Title |
|---|
| 《基于应力概率密度和功率谱密度法的随机声疲劳寿命预估方法研究》;沙云东等;《振动与冲击》;20100125;第29卷(第1期);162-165 |
| 《飞机空腔结构金属壁板声振疲劳研究》;苏欢 邱志平;《北京力学会第二十二届学术年会》;20160109;Ⅱ-110、Ⅱ-111 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105760577A (en) | 2016-07-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105760577B (en) | A kind of evaluation method containing uncertain metal structure sound and vibration fatigue life | |
| US7925475B2 (en) | Analyzing structural design relative to vibrational and/or acoustic loading | |
| Araújo et al. | Operational modal analysis using SVD of power spectral density transmissibility matrices | |
| Putra et al. | Reducing cyclic testing time for components of automotive suspension system utilising the wavelet transform and the Fuzzy C-Means | |
| CN105675056B (en) | Long-span bridge damage recognition method | |
| Kong et al. | Mission profiling of road data measurement for coil spring fatigue life | |
| De Pauw et al. | Operational modal analysis of flow-induced vibration of nuclear fuel rods in a turbulent axial flow | |
| CN115270239A (en) | Bridge reliability prediction method based on dynamic characteristics and intelligent algorithm response surface method | |
| CN108595794A (en) | A kind of pipeline structure oscillating load analysis method | |
| Hémon et al. | Simulation of a spatially correlated turbulent velocity field using biorthogonal decomposition | |
| CN110455477B (en) | Method for acquiring vibration load spectrum of solid rocket cabin section structure | |
| Pagani et al. | Static and dynamic testing of a full-composite VLA by using digital image correlation and output-only ground vibration testing | |
| Chin et al. | Durability prediction of coil spring through multibody-dynamics-based strain generation | |
| CN109902386B (en) | Composite material structure impact load identification method and device based on group sparsity | |
| Li et al. | A new aerodynamic identification technology for short-time hypersonic wind tunnels while considering inertial force interference | |
| Barone et al. | Pressure loading within rectangular cavities with and without a captive store | |
| Łukasiewicz et al. | Analysis of vibrodiagnostics methods in the technical state study of designed multimedia mobile scenes | |
| Lee et al. | Decomposition of surface pressure fluctuations on vehicle side window into incompressible/compressible ones using wavenumber-frequency analysis | |
| Rodzewicz | Determination and extrapolation of the glider load spectra | |
| Al-Bahkali et al. | Failure and fatigue life estimate of a pre-stressed Aircraft seat support tube | |
| Bistrian et al. | Comparison of optimized Dynamic Mode Decomposition vs POD for the shallow water equations model reduction with large-time-step observations | |
| Bolander et al. | Near-field Pressure Signature Splicing for Low-Fidelity Design Space Exploration of Supersonic Aircraft | |
| Yang et al. | Statistical pattern recognition for structural health monitoring using esn feature extraction method | |
| Poirion et al. | Airship gust response probabilistic model construction | |
| Davis Jr et al. | The use of wind tunnels to predict flight buffet loads |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20190222 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |