Accelerated degradation test prediction method based on fuzzy theory
A technology of accelerated degradation test and fuzzy theory, applied in the field of life prediction, can solve the problems of ambiguity of performance failure criterion and inability to describe engineering practice well
Inactive Publication Date: 2011-01-12
BEIHANG UNIV
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[0023] The purpose of the present invention is to solve the problem that in the accelerated degradation test, due to the ambiguity of the performance failure criterion, the previous conventional life and reliability mathematical models cannot describe the actual engineering well. By borrowing the stress intensity interference theory, based on fuzzy mathematics and The correlation fuzzy statistical method combines the drift Brownian motion describing the performance degradation process with the membership function describing the performance failure threshold to form a set of life prediction models and prediction evaluation methods for accelerated degradation tests based on fuzzy theory
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Embodiment 1
[0128] The method of the invention adopts a Monte Carlo simulation method to verify its correctness.
[0129] Assuming that there are 25 products divided into 5 groups, CSADT with 5 temperature levels is carried out. The test parameters are shown in Table 1.
[0130] Table 1 CSADT test parameters
[0131]
[0132]
[0133] During the simulation process, it is assumed that the product performance degradation process obeys the drift Brownian motion, and its drift coefficient d(s) is an Arrennius model. At this time, the stress s is written as the absolute temperature T, then d(T)=exp(A-B / T). Then the Brownian motion of the product's performance degradation drift can be written as:
[0134] Y(t)=σB(t)+exp(A-B / T)·t+y 0
[0135] Among them, suppose A=9000, B=4800, diffusion coefficient σ=0.25, initial value y 0 =124. Then the performance degradation curve of the product obtained by simulation is as follows: image 3 shown. Depend on image 3 It can be seen that the b...
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The invention discloses an accelerated degradation test prediction method based on fuzzy theory, which comprises the following steps: collecting test data; performing the analysis of regression aiming at performance degradation data under each stress level; extrapolating the performance degradation rate of the product under a normal stress level; estimating a diffusion coefficient sigma in an excursion Brownian motion with drift by adopting a maximum likelihood estimation method; establishing an accelerated degradation test life and reliability predication model based on the fussy theory; andpredicting the life and the reliability of the product by adopting the fussy life and reliability prediction model. The method firstly introduces the fussy concept into an accelerated degradation test to enable the prediction result of the accelerated degradation test to be more reasonable, avoids the condition of rash routine reliability estimation result through considering the fussiness fuzziness of the performance degradation threshold, solves the problem of failed performance degradation in the engineering reality, and is suitable for the accelerated degradation tests of step stress and progressive stress and unaccelerated performance degradation prediction for the problem of the performance degradation failure.
Description
technical field [0001] The invention relates to a life prediction method in an accelerated degradation test, and belongs to the technical field of life prediction. Background technique [0002] 1. Accelerated degradation test [0003] With the development of science and technology, the requirements for product reliability are getting higher and higher. For products with long life and high reliability, the accelerated life test (ALT-Accelerated Life Testing) using the failure data observed in the test has become somewhat inadequate. Since the failure of long-life and high-reliability products is difficult to observe or not observed in ALT, it brings great difficulties to the evaluation of product life and reliability. Accelerated degradation test (ADT-Accelerated Degradation Testing) was developed under this background. The so-called accelerated degradation test is to use the performance degradation data of the product under high (accelerated) stress levels to extrapolate o...
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IPC IPC(8): G01D21/00G06F17/17
Inventor 李晓阳孙富强姜同敏黄婷婷
Owner BEIHANG UNIV