scholarly journals Resolution of indeterminate landing gear structure design

Author(s):  
Bradley James Greenland

Aircraft landing gear structural designs involves a balance of weight, cost and robustness while not compromising on safety. On some large commercial aircraft, the introduction of a second main supporting brace has led to an indeterminate structure in that there is redundancy in the load paths. This introduces two major challenges for structural design. The first challenge involves the introduction of a multiple load path. Understanding load path in the landing gear is critical in order to optimize the structure for weight. This report focuses on analysis techniques geared to resolving this indeterminate load path in order to mitigate this risk and optimize the design. The second major challenge is introduced by a compressive load in one of the braces during an in flight airload condition which impedes the ability for the landing gear to freefall, which is a requirement in aircraft design. Solving this problem involves introducing a pretension in the brace by force shortening the geometry. An indeterminate design introduces increased complexity and requires more simulation and analysis than that of a determinant design in order to accomplish the optimization demanded by the aerospace industry.

2021 ◽  
Author(s):  
Bradley James Greenland

Aircraft landing gear structural designs involves a balance of weight, cost and robustness while not compromising on safety. On some large commercial aircraft, the introduction of a second main supporting brace has led to an indeterminate structure in that there is redundancy in the load paths. This introduces two major challenges for structural design. The first challenge involves the introduction of a multiple load path. Understanding load path in the landing gear is critical in order to optimize the structure for weight. This report focuses on analysis techniques geared to resolving this indeterminate load path in order to mitigate this risk and optimize the design. The second major challenge is introduced by a compressive load in one of the braces during an in flight airload condition which impedes the ability for the landing gear to freefall, which is a requirement in aircraft design. Solving this problem involves introducing a pretension in the brace by force shortening the geometry. An indeterminate design introduces increased complexity and requires more simulation and analysis than that of a determinant design in order to accomplish the optimization demanded by the aerospace industry.


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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