scholarly journals Fault Tree Interval Analysis of Complex Systems Based on Universal Grey Operation

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Feng Zhang ◽  
Shiwang Tan ◽  
Leilei Zhang ◽  
Yameng Wang ◽  
Yang Gao
Keyword(s):  
Failure Probability ◽  
System Reliability ◽  
Fault Tree ◽  
Landing Gear ◽  
Aircraft Landing ◽  
Interval Operation ◽  
Aircraft Landing Gear ◽  
Grey Number ◽  
Conversion Rules ◽  
Interval Enlargement

The objective of this study is to propose a new operation method based on the universal grey number to overcome the shortcomings of typical interval operation in solving system fault trees. First, the failure probability ranges of the bottom events are described according to the conversion rules between the interval number and universal grey number. A more accurate system reliability calculation is then obtained based on the logical relationship between the AND gates and OR gates of a fault tree and universal grey number arithmetic. Then, considering an aircraft landing gear retraction system as an example, the failure probability range of the top event is obtained through universal grey operation. Next, the reliability of the aircraft landing gear retraction system is evaluated despite insufficient statistical information describing failures. The example demonstrates that the proposed method provides many advantages in resolving the system reliability problem despite poor information, yielding benefits for the function of the interval operation, and overcoming the drawback of solution interval enlargement under different orders of interval operation.

Importance analysis based on universal grey operation for an aircraft landing gear retraction system

2021 ◽  
pp. 1-11
Author(s):  
Feng Zhang ◽  
Mingying Wu ◽  
Xinting Hou ◽  
Xinhe Wang ◽  
Cheng Han ◽  
...  
Keyword(s):  
Failure Probability ◽  
Oil Pollution ◽  
Landing Gear ◽  
Weak Links ◽  
System Failure ◽  
Aircraft Landing ◽  
Interval Operation ◽  
Importance Analysis ◽  
Grey Number ◽  
And Performance

In order to improve the reliability and performance of landing gear retraction systems, this paper presents two importance analysis methods based on universal grey operation. According to the system principle and fault mechanisms, the fault tree of the retraction system was first established. The uncertainties of the bottom events were then described using the universal grey number to obtain the universal grey representation of the system failure probability. And compared with the traditional interval operation, the results show that universal grey operation can solve the problem of interval expansion with uncertainty. Importance analyses of the bottom events were then conducted based on the probability importance and the key importance. By comparing the two important indices of the bottom events, the larger the value is, the higher the importance is. It was found that the occurrence of the bottom events “pipeline oil leakage,” “pump motor damage,” and “oil pollution” had the greatest impact on system failure probability, thus determining the key weak links affecting system failure and indicating the most effective targets for improvement.

Improved uncertain method for safety analysis of aircraft landing gear

2021 ◽  
pp. 095441002110005
Author(s):  
Xintian Liu ◽  
Shuanglong Geng ◽  
Xueguang Yu ◽  
Jiachi Tong ◽  
Yansong Wang
Keyword(s):  
Number Theory ◽  
Mixed Method ◽  
Landing Gear ◽  
Interval Method ◽  
Truncation Method ◽  
Manufacturing Tolerance ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Practical Engineering ◽  
Grey Number

There are various uncertain factors in most practical engineering applications, such as input loads, structural sizes, manufacturing tolerance, and initial and boundary conditions. The interval method and grey number theory are common methods to deal with uncertainty. In this article, the interval truncation method and grey number theory are improved. And a mixed method is proposed to represent the confidence interval of output result based on the improved interval truncation method and improved grey number theory. The proposed methods’ feasibility is verified by a stepped bar; the methods are applied to the analysis of aircraft landing gear safety uncertainty.

scholarly journals 1002 Aerodynamic noise reduction for aircraft landing gear

2009 ◽  
Vol 2009 (0) ◽  
pp. 321-322
Author(s):  
Kazuhide Isotani ◽  
Kenji Hayama ◽  
Akio Ochi ◽  
Toshiyuki Kumada
Keyword(s):  
Noise Reduction ◽  
Landing Gear ◽  
Aerodynamic Noise ◽  
Aircraft Landing ◽  
Aircraft Landing Gear

Nonlinear Transient Analysis of Aircraft Landing Gear Brake Whirl and Squeal

1995 ◽  
Author(s):  
Matt H. Travis
Keyword(s):  
Finite Element ◽  
Transient Analysis ◽  
Landing Gear ◽  
Friction Modeling ◽  
Explicit Integration ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Nonlinear Transient ◽  
Element Approach ◽  
Stiffness And Damping

Abstract The feasibility of computing non-linear transient finite element simulations of aircraft landing gear brake whirl and squeal is demonstrated and discussed. Methodology to conduct the high frequency brake transient analysis is developed using an explicit integration finite element approach. Results indicate the approach has the capability to simulate brake dynamic behavior in dynamometer and aircraft landing gear installations — thus enabling evaluation of modifications to braking systems that lead to more stable and robust designs. A simple multi-disk brake model is developed and described. Modeling techniques for including the dynamometer road wheel and runway in the simulations are given. Issues such as piston housing hydraulic fluid stiffness and damping effects, and parametric friction modeling are discussed.

Study on Magneto-rheological Damper Control of Aircraft Landing Gear Based on LADRC

2021 ◽  
pp. 830-840
Author(s):  
Lei Dong ◽  
Zengqiang Chen ◽  
Mingwei Sun ◽  
Qinglin Sun ◽  
ZhenPing Yu
Keyword(s):  
Landing Gear ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Damper Control ◽  
Magneto Rheological
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