Research On Dynamic Reliability Of Products With Variable Threshold Based On Competitive Failure

Since the inception of reliability engineering appeared in the middle of the last century,reliability engineering has always been an indispensable content in academic research hotspots and modern design theories due to its ability to ensure product quality and safety.At present,reliability theory and research results have been widely used in aerospace,machinery,electronics and other fields.With the advancement of science and technology,products generally have the characteristics of high quality and long life.The high integration and high stability of products directly lead to high test costs and difficult data collection during life prediction and reliability analysis.The problem of obtaining less data,which makes traditional reliability analysis methods that rely on a large amount of failure data subject to greater constraints in the application process.Some performance degradation data generated during the use of the product can also reflect the reliability of the product.Through the research of this type of data,we can effectively solve the situation that the lack of invalid data affects the evaluation process.In addition,reliability analysis methods based on performance degradation data can also effectively save test costs.As a result,this method has become a research hotspot in the field of reliability,and this article will conduct related research on such problems.The main research contents and results are listed as follows:(1)The basic theory of reliability analysis based on performance degradation is introduced,and the reliability of products based on this theory is given.After the overall analysis process,it focuses on the related concepts of soft failure and hard failure and the basic idea of competitive failure.The mainstream mathematical models describing the product degradation process are analyzed and compared.(2)In view of the high-quality and long-life characteristics of products at this stage,the theory of accelerated degradation test is introduced.On the basis and test methods.The experiment aims at the speed of obtaining degradation data quickly,and solves the related problems of experimental design and model selection involved in quickly obtaining performance degradation data.In addition,this article also gives the method of processing performance degradation data,as well as the fitting of related parameters of the degradation model.The data in the literature is cited as an analysis example to verify the accuracy and applicability of the given process.(3)The reliability analysis method of softening failure threshold based on degradation trajectory model is given.Based on the modeling ideas of competitive failure and variable failure threshold,the modeling idea of failure threshold comprehensively considers various influencing factors that affect the performance degradation process,realizes the multi-stage expression of the competitive failure process,and more comprehensively describes the entire product failure process.In addition,in view of the relatively complex characteristics of the current product working conditions,the modeling work of refining the impact process experienced by the product has been completed.The concept of impact damage and intensive impact is introduced to improve the traditional impact model,and the use of Stillgers integral solves the problem of the impact arrival time that is not easy to introduce a reliability model,and proposes an extreme impact competitive failure model based on impact damage and considerations Competitive failure model of delta shock with dense shock.Finally,the reliability of a micro engine is evaluated by using the proposed model,and the influence of each parameter on the reliability of the model is analyzed,and compared with the conventional reliability model.The results show that the established model can better describe the competitive failure process of products,and has certain feasibility and theoretical value.(4)Completed the reliability analysis modeling of hardening threshold products based on stochastic process model.Aiming at the two-stage degradation characteristics of products summarized in existing research,combined with the characteristics of current products that generally limit storage time,combined with the characteristics of current products that generally have limited storage time,the product degradation process is refined into one storage stage and two working stages.Different from the traditional stochastic process analysis model,this model fully applies the idea of competitive failure.While completing the three-stage modeling of the soft failure process,it also joined the discussion about the impact process based on the hardening failure threshold,and proposed a three-stage reliability assessment model for the whole life cycle.Finally,a simulation process is given to verify the model.The results show that the model can describe the competitive failure process well and can meet the analysis requirements of related products.