Improved uncertain method for safety analysis of aircraft landing gear

Author(s):  
Xintian Liu ◽  
Shuanglong Geng ◽  
Xueguang Yu ◽  
Jiachi Tong ◽  
Yansong Wang

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.

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Feng Zhang ◽  
Shiwang Tan ◽  
Leilei Zhang ◽  
Yameng Wang ◽  
Yang Gao

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.


2009 ◽  
Vol 2009 (0) ◽  
pp. 321-322
Author(s):  
Kazuhide Isotani ◽  
Kenji Hayama ◽  
Akio Ochi ◽  
Toshiyuki Kumada

Author(s):  
Matt H. Travis

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.


2021 ◽  
pp. 830-840
Author(s):  
Lei Dong ◽  
Zengqiang Chen ◽  
Mingwei Sun ◽  
Qinglin Sun ◽  
ZhenPing Yu

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