Degradation rate-fluctuation combined updated storage life evaluation method for sealing rubber for missile

Abstract

The invention provides a degradation rate-fluctuation combined updated storage life evaluation method for sealing rubber for a missile. The method comprises the following steps: step 1, establishing a random degradation process model; step 2, determining prior distribution of model parameters; step 3, determining posterior distribution of model parameters; and step 4, comparing and analyzing by adoption of a storage life fusion evaluation method. Through the steps, according to natural and accelerated degradation test data of a degraded high-reliability and long-life product, a product accelerated degradation model is established according to a random process theory and an accelerated model, model parameters are estimated by applying a maximum likelihood estimation method, and then accelerated data model parameters are equivalent to natural model parameters; and then prior distribution of model parameters is determined, posterior distribution of the model parameters is updated based on natural degradation data by using a Bayesian theory, and finally accuracy of storage life estimation is ensured.

Description

technical field [0001] The invention relates to a degradation rate-fluctuation joint updating method for evaluating the storage life of elastic sealing rubber, which is a method for evaluating the storage life of degraded products based on stochastic process theory and Bayesian theory. For the natural and accelerated degradation test data of degraded products, it establishes the random degradation model of the Wiener process ("Wiener process" refers to the independent normal incremental process, also known as the Brownian motion process), and the distribution parameters of the accelerated degradation data Carry out maximum likelihood estimation, combined with the Arrhenius acceleration model ("Arrhenius acceleration model" refers to the physical model describing the relationship between product life and temperature stress), the accelerated degradation data model parameters are equivalent to the natural degradation model parameters, obtain the prior information of model paramet...

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Problems solved by technology

[0003] (1) The purpose of the present invention is to propose a degradation rate-fluctuation joint update method for the problem that the rubber of the sealing component of high reliability and long-life aerospace products has a small failure sample in the accelerated life test, which leads to the inability to accurately evaluate the storage life. The storage life evaluation method of elastic sealing rubber is a degraded rubber life evaluation method based on stochastic process theory and Bayesian theory

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