Papers by Keyword: Life Distribution

Abstract: With the development of science and technology, the quality of the product is better and better. Consequently, in the time-ended life tests, zero-failure data is of frequent occurrence． So the evaluation of the product’s life has important meaning and greatly practical value． While Bayesian estimation is a very effective method about the analysis of the product’s zero-failure data. In the paper, Bayesian estimation of failure probability of zero-failure data are take out, combined linear fitting method and the software of Matlab, the method to ascertain types of product’s life distribution is come out according to zero-failure data. Finally calculation is performed regarding to zero-failure data of a certain model engine, and ascertain the equation of the engine’s life distribution.

Abstract: Characteristics of field failure data are analyzed in this paper. The failure data and sales record of LZL-type mass flowmeter are used to infer life distribution of this conduct. The lines can be fitted in coordinates of six distribution using least square and the residual sum of squares are compared, the minimum correspond is the best distribution type. The results show that the life distribution style of this conduct is the two parameter exponential distribution, which is the base to analyze and predict failure development, research failure mechanism and draw up maintenance policy.

Abstract: By interpreting traditional stress-strength interference model as a statistical average of the probability that strength (a random variable) is greater than stress (another random variable) over its whole distribution range, the same model configuration, which was conventionally applied only to the case of same system-of-units parameters (e.g., stress and strength, both are measured in MPa), was applied to more general situation of different system-of-units parameters. That is to say, the traditional model was extended to more general situations of any two variables, as long as one of the variables can be expressed as a function of the other. Further more, the probabilistic fatigue life under random stress can be predicted, with known probabilistic fatigue lives under several deterministic cyclic stress amplitudes and known distribution of the random cyclic stress amplitude. The underlying principle is that the fatigue life under random stress is equal to the statistical average of the fatigue lives under cyclic stress of deterministic amplitudes which can be considered as the samples of the random stress.

Abstract: The present paper interpreted the traditional stress-strength interference model as an equation expressing the statistical average of the probability of strength preponderating over stress. Thus, the same equation, which was traditionally applicable only in the situation of same-measure parameters, can be applied to more general situation of different-measure parameters. In other words, the traditional model was extended to the situation of any two variables, as long as one variable can be expressed as a function of the other. With a specific load amplitude distribution, the method is to calculate the statistical average of the probability that fatigue life random variable under the individual constant amplitude cyclic load is greater than an assigned value. The extended interference analysis method can be applied directly to calculate fatigue reliability under constant amplitude cyclic load with uncertainty in the stress range.