Reliability Assessment Based on Performance Parameter for Micro-Gyro

2014 ◽  
Vol 1037 ◽  
pp. 197-200
Author(s):  
Li Xia Yu ◽  
Li Qin ◽  
Meng Mei Wang
Keyword(s):  
High Reliability ◽  
Reliability Assessment ◽  
Assessment Method ◽  
Accelerated Life Test ◽  
Time To Failure ◽  
Accelerated Life ◽  
Parameter Measuring ◽  
Failure Life ◽  
Effective Assessment ◽  
Short Time

For high-reliability and long-lifetime product, it is difficult to assess the reliability with traditional accelerated life test that record only time to failure. Aiming to solve the problem of the previously, a reliability test and assessment method forecasting the life of samples based on degradation parameter was proposed. According to the working characteristic, the key parameter measuring performance degradation was selected. Based on statistical analysis methods, parameter degradation was designed and parameter degradation model was build. Combined with practical application background, the failure threshold was set and reliability assessment resultwas obtained. The method is applied to assessing reliability of micro gyroscope. The application shows that the method can achieve effective assessment, which can be used as similar products that are difficult to obtain the failure life data in a short time.

Reliability Assessment Based on Multisource Information Fusion Method for High Pressure Natural Gas Compressors

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Dengji Zhou ◽  
Tingting Wei ◽  
Dawen Huang ◽  
Maozong Liang ◽  
Huisheng Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Information Fusion ◽  
High Reliability ◽  
Reliability Assessment ◽  
Assessment Method ◽  
Operation And Maintenance ◽  
High Pressure Compressor ◽  
Component Test ◽  
Pressure Compressor

Abstract Compressor units used for long-distance transportation natural gas pipeline pressurization have high-pressure and high-risk characteristics. Hence, the scientific reliability assessment is important for high-pressure compressor units, to evaluate the reliability standard, find the performance deficiency, and provide references for operation and maintenance. The classical reliability assessment method is not suitable for the complex and high-reliability equipment, like high-pressure compressor units and pipelines. The reliability assessment of the high-reliability equipment is faced with the challenge of the multisource information. A reliability assessment method based on the multisource information fusion is proposed in this work. The fusion resources consist of design information, component test information, and trial operation information. The reliability of high-pressure compressor units can be assessed by fusing the characteristic parameters, from component-based assessment, function-based assessment, quality evaluation, and life model, by D–S evidence theory. A case study is conducted to verify the proposed reliability assessment method in a 20 MW-class high-pressure compressor. There are four information resources in the case, i.e., component test data, design information, operation data, and simulation data. The compressor reliability is assessed as 99.32%, validated by the statistical assessment result based on long-term shutdown reports. This application points out the existing weakness in the high-pressure compressor units and indicates the directions for improving the design, analysis, operation, and failure prevention technologies. It reveals that the reliability assessment based on multisource information can provide a guarantee for the operation and maintenance of high-pressure compressor units. Meanwhile, the proposed method has good expansibility, which may be used in more fields.

An accelerated life test plan for a two-component parallel system under ramp-stress loading using masked data

2018 ◽  
Vol 35 (3) ◽  
pp. 811-820 ◽  
Author(s):  
Preeti Wanti Srivastava ◽  
Savita Savita
Keyword(s):  
Optimality Criterion ◽  
High Reliability ◽  
Parallel System ◽  
Stress Rate ◽  
Accelerated Life Test ◽  
Cumulative Exposure ◽  
Life Test ◽  
Optimal Plan ◽  
Content Type ◽  
Accelerated Life

Purpose Most of the literature on the design of accelerated life test (ALT) plan focus on a single system (subsystem) totally disregarding its internal configuration. Many a times it is not possible to identify the components that cause the system failure or that the cause can only be identified by a subset of its components resulting in a masked observation. The purpose of this paper is to deal with the planning of ramp-stress accelerated life testing for a high-reliability parallel system comprising two dependent components using masked failure data. Such a testing may prove to be useful in a twin-engine aircraft. A ramp-stress results when stress applied on the system increases linearly with time. Design/methodology/approach A parallel system with two dependent components is taken with dependency modeled by Gumbel-Hougaard copula. The stress-life relationship is modeled using inverse power law, and cumulative exposure model is assumed to model the effect of changing stress. The method of maximum likelihood is used for estimating design parameters. The optimal plan consists in finding optimal stress rate using D-optimality criterion. Findings The optimal plan consists in finding optimal stress rate using D-optimality criterion by minimizing the reciprocal of the determinant of Fisher information matrix. The proposed plan has been explained using a numerical example and carrying out a sensitivity analysis. Originality/value The model formulated can help reliability engineers obtain reliability estimates quickly of high-reliability products that are likely to last for several years.

scholarly journals Accelerated Lifetime Data Analysis with a Nonconstant Shape Parameter

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Guodong Wang ◽  
Zhanwen Niu ◽  
Zhen He
Keyword(s):  
Shape Parameter ◽  
High Reliability ◽  
Least Square Method ◽  
Least Square ◽  
Accelerated Life Test ◽  
Stress Factors ◽  
Likelihood Method ◽  
Accelerated Life ◽  
Lifetime Data Analysis ◽  
Accelerated Lifetime

Accelerated life test is commonly used for the estimation of high-reliability product. In this paper, we present a simple and efficient approach to estimate the coefficients of acceleration models. Assuming that both scale and shape parameters of Weibull lifetime distribution vary with stress factors, we estimate the parameters of Weibull distribution using maximum likelihood method and reduce the bias of shape parameter estimator. Considering the heteroscedasticity, we compute the estimates of the coefficients of acceleration models through weighted least square method. Additionally, we obtain the confidence interval of low percentile via bootstrapping. We compare the proposed method with other methods using a real lifetime example. Finally, we study the performance of the proposed method by simulation. The simulation results show that our proposed method is effective.

Comparison of Aluminum Electrolytic Capacitor Lifetimes Using Accelerated Life Testing

2014 ◽  
Vol 2014 (1) ◽  
pp. 000662-000667 ◽  
Author(s):  
Stephani Gulbrandsen ◽  
Joelle Arnold ◽  
Greg Caswell ◽  
Ken Cartmill
Keyword(s):  
Weight Loss ◽  
Operating Conditions ◽  
Accelerated Life Test ◽  
Electrolytic Capacitor ◽  
Time To Failure ◽  
Equivalent Series Resistance ◽  
Aluminum Electrolytic Capacitor ◽  
Critical Weight ◽  
Accelerated Life ◽  
Speed Up

This research compared the lifetime of similar aluminum electrolytic capacitors from different manufacturers using an accelerated life test, which consisted of critical weight loss testing and rate of weight loss testing. In critical weight loss testing, capacitors are perforated to speed up electrolyte evaporation and the equivalent series resistance (ESR) and weight are measured periodically to determine their relationship. In rate of weight loss testing, capacitors are subjected to final operating conditions (i.e. voltage and ripple current are applied) and the weight is periodically measured over the course of 500 hours. After test completion the relationship between ESR and weight loss is used to calculate the critical weight loss that occurs at datasheet-defined failure, which is typically a 200% increase in ESR. The rate of weight loss is extrapolated to the critical weight to estimate a time to failure that can be compared to other capacitors tested using the same accelerated approach. In this research, testing compared 450 V, 68 μF capacitors from Manufacturer A and Manufacturer B, and results indicated Manufacturer A had a significantly longer lifetime. Therefore, capacitors from Manufacturer A are more reliable than capacitors from Manufacturer B.

Accelerated Reliability Growth Testing and Data Analysis Method

2007 ◽  
Vol 50 (2) ◽  
pp. 98-117 ◽  
Author(s):  
Milena Krasich
Keyword(s):  
Data Analysis ◽  
Failure Modes ◽  
High Reliability ◽  
Real Life ◽  
Accelerated Life Test ◽  
Analytical Models ◽  
International Electrotechnical Commission ◽  
Reliability Growth ◽  
Time To Failure ◽  
Growth Test

Traditionally, a reliability growth test was performed at the levels of various operational and environmental stresses, often at a level equal to that expected in use. Other than formal failure modes and effects analysis, reliability growth tests were often the only practical means for identification and mitigation of failure modes of a newly designed product. With the present high reliability requirements and long product useful life, the length of reliability growth tests may become cost and schedule prohibitive; therefore, accelerated testing is taking the place of prior testing at the use levels. This practice, however, does not address the dilemma of possibly unrealistically skewed test results highly dependent on the sequence of individually applied stresses as, unfortunately, it is often difficult to impossible to apply all of the environmental and operational stresses simultaneously. An example of this problem would be a case where the majority of failure modes in a product are a result of or are related to a specific stress, and this test was performed early in the program. These early failures would then produce a high growth rate and an incorrect estimate of the product achieved reliability if the analysis were done by standard analytical models. The test data also may be skewed in the opposite way, producing little or no reliability growth. This concern has been addressed as a serious caution in Edition 2 of the International Electrotechnical Commission (IEC) 61014 Programmes for reliability growth. This study shows how data analysis applied to an accelerated life test based on reliability growth methodology may produce a viable solution to the calculation problems. The stresses applied in this test are an accelerated application of most of the stresses expected to take place during product use. Each of the tests represents a lifetime exposure to an individual stress. If those stresses are applied individually and in sequence, they are considered to be equivalent to being applied in parallel with one another, as the duration of each stress is calculated to represent life of the product. Time to failure in each test is re-calculated to represent time to failure in real life. Failure occurrences are then sorted in their increasing order and analyzed using one of the reliability growth test analytical methods.

The Statistics Analysis of Degradation Data Based on the Degradation Amount Distribution

2013 ◽  
Vol 791-793 ◽  
pp. 1260-1263
Author(s):  
Yi Zhou He ◽  
Jin Huang Wu ◽  
Yi Dong Wang ◽  
Wei Hua Liu
Keyword(s):  
High Reliability ◽  
Performance Degradation ◽  
Accelerated Life Test ◽  
Test Reliability ◽  
Analysis Method ◽  
Life Test ◽  
Failure Data ◽  
Degradation Data ◽  
Accelerated Life ◽  
Long Life

In order to solve the key technology and method in reliability study of the long-life products, the analysis method of degradation data based on the degradation amount distribution was proposed in this paper. On the basis of statistical model, by analyzing three models of degradation amount distribution, it can be got there is a large number of reliability information with high-reliable and long-life products in performance degradation data. In the case of not getting the failure data by life test and accelerated life test, reliability assessment and life prediction could be carried out for high reliability and long life products with performance degradation data.

An intelligent performance degradation assessment method for bearings

2016 ◽  
Vol 23 (18) ◽  
pp. 3023-3040 ◽  
Author(s):  
Huiming Jiang ◽  
Jin Chen ◽  
Guangming Dong ◽  
Ran Wang
Keyword(s):  
Evaluation System ◽  
Health Management ◽  
Feature Space ◽  
Assessment Method ◽  
Performance Degradation ◽  
Accelerated Life Test ◽  
Time Data ◽  
Accelerated Life ◽  
Rolling Element ◽  
Close Relationship

Bearings are one of the most frequently used components in the rotatory machinery, so the performance degradation assessment of bearings plays an important role in the prognostics and health management of systems. Hidden Markov model (HMM) is a widely applied data-driven model used for bearing performance degradation assessment and has many successful applications. A normal HMM needs to be trained in advance, which has close relationship with the evaluation system. However, the trained HMM is quite influenced by many issues, such as the data integrity and the feature space. In this paper, an intelligent bearing performance degradation assessment method based on HMM and nuisance attribute projection (NAP) is proposed. The proposed method can combine the information from the experimental data and the real-time data effectively and assess the performance since the beginning of the monitoring. The effectiveness of the proposed method is verified through an accelerated life test of rolling element bearings.

scholarly journals Accelerated competing risks model from Gompertz lifetime distributions with type-II censoring scheme

2020 ◽  
Vol 24 (Suppl. 1) ◽  
pp. 165-175
Author(s):  
Abdullah Almarashi ◽  
Gamal Abd-Elmougod
Keyword(s):  
Accelerated Life Test ◽  
Likelihood Method ◽  
Model Parameters ◽  
Test Model ◽  
Time To Failure ◽  
Type Ii ◽  
Type Ii Censoring ◽  
Accelerated Life ◽  
Interval Estimators ◽  
Censoring Scheme

Time to failure under normal stress conditions may take a long period of time and statistical inferences under this condition is more serious. Then, the experiment is loaded under stress higher than normal one which is defined as accelerated life tests. This problem in this paper is discussed in the form of partially step-stress accelerated life test model when the lifetime of the product has Gompertz lifetime distribution and unites are fails under the two independent risks. The maximum likelihood method under type-II censoring scheme is used to formulate the point and asymptotic confidence interval estimators of model parameters. The two boot?strap methods are also used to formulate the point and approximate interval estimators. The numerical results are adopted in the form of Monte Carlo studying to illustrate, assess and compare all of the theoretical results. Finally, results are discussed in points to clarify results validity.

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