Effect of the Impact Load on the Main Welding Outer Cylinder of Large Aircraft Landing Gear

2013 ◽  
Vol 567 ◽  
pp. 169-173
Author(s):  
Hong Feng Wang ◽  
W.W. Song ◽  
J.L. Wang ◽  
Dun Wen Zuo ◽  
X.L. Duan
Keyword(s):  
Life Prediction ◽  
Impact Load ◽  
Outer Cylinder ◽  
Element Model ◽  
Landing Gear ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
The Impact ◽  
Important Basis ◽  
Large Aircraft

Analysis about the cause of the main failure and the forces of the main welding outer cylinder of the recent large aircraft landing gear were given. The impact load for main welding outer cylinder in the process of the taking off and landing was calculated of 580MPa. Finite element model of the main welding outer cylinder was then established and the influence of the impact loading to the main welding outer cylinder was analyzed. The results showed that crack was most likely take place on the top of the outer cylinder, and then on the two welds. The crack expanded in an S shape. This study could provide an important basis for the safety of the aircraft landing gear inspection and service life prediction.

Impact Loading Analysis of Light Sport Aircraft Landing Gear

2014 ◽  
Vol 518 ◽  
pp. 252-257 ◽  
Author(s):  
Pu Woei Chen ◽  
Shu Han Chang ◽  
Chan Ming Chen
Keyword(s):  
Simulation Model ◽  
Impact Loading ◽  
Loading Condition ◽  
Element Model ◽  
Landing Gear ◽  
Market Demand ◽  
Critical Loading ◽  
Aircraft Landing ◽  
Aluminum Plates ◽  
The Impact

This paper examined the critical loading condition of a light sport aircrafts main landing gear during the impact loading condition. The new category airplane was established by the FAA in 2004. The light sport aircraft has great market demand for personnel entertainment purpose and regional transportation. The main object of this research was to establish a static and dynamic loading simulation model for the aluminum alloy landing gear of a light sport aircraft. This work also examined the critical loading parameters of the main landing gear, including the maximum take-off weight and maximum stall speed. The analysis was performed using ANSYS and LS-DYNA to establish the finite element model after simplifying the geometric characteristics and verifying the results by energy conservation, hourglass energy, and sliding energy. The study tested aluminum plates with a thickness from 15~25 mm. The results showed all the samples could sustain the required loading condition, except for the thickness of 15mm that failed under impact loading. The simulation model provides a cost-saving process compared to a real crashworthiness drop test to test the main landing gears compliance with regulations.

Aircraft landing gear failure: fracture of the outer cylinder lug

2002 ◽  
Vol 9 (1) ◽  
pp. 1-15 ◽  
Author(s):  
C.R.F Azevedo ◽  
E Hippert ◽  
G Spera ◽  
P Gerardi
Keyword(s):  
Outer Cylinder ◽  
Landing Gear ◽  
Aircraft Landing ◽  
Aircraft Landing Gear

scholarly journals A Supervised Neural Network Control for Magnetorheological Damper in an Aircraft Landing Gear

2021 ◽  
Vol 12 (1) ◽  
pp. 400
Author(s):  
Quoc-Viet Luong ◽  
Bang-Hyun Jo ◽  
Jai-Hyuk Hwang ◽  
Dae-Sung Jang
Keyword(s):  
Neural Network ◽  
Mr Damper ◽  
Landing Gear ◽  
Network Control ◽  
Neural Network Control ◽  
Hybrid Controller ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Drop Tests ◽  
The Impact

This paper adopts an intelligent controller based on supervised neural network control for a magnetorheological (MR) damper in an aircraft landing gear. An MR damper is a device capable of adjusting the damping force by changing the magnetic field generated in electric coils. Applying an MR damper to the landing gears of an aircraft could minimize the impact at landing and increase the impact absorption efficiency. Various techniques proposed for controlling the MR damper in aircraft landing gears require information on the damper force or the mass of the aircraft to determine optimal parameters and control commands. This information is obtained by estimation with a model in a practical operating environment, and the accompanying inaccuracies cause performance degradation. Machine learning-based controllers have also been proposed to address model dependency but require a large number of drop test data. Unlike simulations, which can conduct a large number of virtual drop tests, the cost and time are limited in the actual experimental environment. Therefore, a neural network controller with supervised learning is proposed in this paper to simulate the behavior of a proven controller only with system states. The experimental data generated by applying the hybrid controller with the exact mass and force information, which has demonstrated high performance among the existing techniques, are set as the target for supervised learning. To verify the effectiveness of the proposed controller, drop test experiments using the intelligent controller and the hybrid controller with and without exact information about aircraft mass and force are executed. The experimental results from the drop tests of a landing gear show that the proposed controller maintains superior performance to the hybrid controller without using explicit damper models or any information on the aircraft mass or strut force.

scholarly journals Effects of Spring and Damper Elements in Aircraft Landing Gear Dynamics

2020 ◽  
Vol 8 (5) ◽  
pp. 4265-4269
Keyword(s):  
Shock Absorber ◽  
Impact Force ◽  
Landing Gear ◽  
Damping Coefficient ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Spring Coefficient ◽  
Mass Spring ◽  
The Impact

In this study a typical Aircraft Landing Gear with shock absorber was modeled a Mass-Spring-Damper System. Basic components of the system were explained. The equations of the model was presented. Aircraft Landing Gear was also modeled in Matlab/Simulink for a given set of aircraft parameters. A case study for an Aircraft Landing Gear was solved and results were presented. Results included the variation of spring (k1 and k2 ) and damping coefficient (b) in a given interval to show their effects on the impact force and displacement of landing gear as main outputs to consider. Effect of damping coefficient (b) on impact force was found to be highest (3.76%), spring coefficient (k1 ) effect is moderate (2.29%), and spring coefficient (k2 ) is lower (0.97%), for a change of ±10% of coefficients.

Multi-Domain Unified Modeling and Simulation for Aircraft Landing Gear Using Modelica

2011 ◽  
Vol 311-313 ◽  
pp. 2457-2460
Author(s):  
Ji Hong Liu ◽  
Ying Zhong Pang ◽  
Yu Ming Zhu
Keyword(s):  
Modeling And Simulation ◽  
Shock Absorber ◽  
Simulation Method ◽  
Heterogeneous Data ◽  
Landing Gear ◽  
Heterogeneous Platforms ◽  
Unified Modeling ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
The Impact

Modern products become more and more complex, the modeling and simulation of them are carried out with different software on heterogeneous platforms, which always caused the heterogeneous data, separated disciplines and cannot obtain the result of unified model correctly. Therefore, a Modelica-based modeling and simulation method for aircraft landing gear is proposed. The landing gear library based on Modelica was established. The unified physical model of landing gear which is composed of structural, thermodynamics and hydromechanics disciplines is constructed. The aircraft landing process, the track of retraction mechanism and the impact work amount of the shock absorber are obtained through multi-domain unified simulation, which provides references for deisgners.

Computer-Aided Multi-Domain Unified Modeling and Simulation for Aircraft Landing Gear

2011 ◽  
Vol 421 ◽  
pp. 392-396
Author(s):  
Yu Ming Zhu ◽  
Hai Cheng Yang
Keyword(s):  
Modeling And Simulation ◽  
Landing Gear ◽  
Domain Modeling ◽  
Complex Product ◽  
Product Systems ◽  
Aircraft Landing ◽  
Aircraft Landing Gear ◽  
Model Complex ◽  
Complex Product Systems ◽  
The Impact

In order to model complex product systems and analyze their whole performance to deal with the coupling relationships between multi-domain，aircraft landing gear selected as the object, unified multi-domain modeling and simulation and for complex product systems was studied. The aircraft leading gear is decomposed as structure, and the mathematical models of the landing gear components are established. The model library of the landing gear components was developed using Modelica-based platform and multi-domain unified model of the landing gear was established. The impact work amount, the vertical load and the stroke are selected as the indexes to simulate and analyze the earthquake resistant performance of the shock absorber.

scholarly journals A Rational Numerical Method for Simulation of Drop-Impact Dynamics of Oleo-Pneumatic Landing Gear

2021 ◽  
Vol 11 (9) ◽  
pp. 4136
Author(s):  
Rosario Pecora
Keyword(s):  
Numerical Method ◽  
Initial Conditions ◽  
Impact Load ◽  
Numerical Models ◽  
Landing Gear ◽  
Design Stage ◽  
Impact Dynamics ◽  
State Variables ◽  
Adopted Model ◽  
The Impact

Oleo-pneumatic landing gear is a complex mechanical system conceived to efficiently absorb and dissipate an aircraft’s kinetic energy at touchdown, thus reducing the impact load and acceleration transmitted to the airframe. Due to its significant influence on ground loads, this system is generally designed in parallel with the main structural components of the aircraft, such as the fuselage and wings. Robust numerical models for simulating landing gear impact dynamics are essential from the preliminary design stage in order to properly assess aircraft configuration and structural arrangements. Finite element (FE) analysis is a viable solution for supporting the design. However, regarding the oleo-pneumatic struts, FE-based simulation may become unpractical, since detailed models are required to obtain reliable results. Moreover, FE models could not be very versatile for accommodating the many design updates that usually occur at the beginning of the landing gear project or during the layout optimization process. In this work, a numerical method for simulating oleo-pneumatic landing gear drop dynamics is presented. To effectively support both the preliminary and advanced design of landing gear units, the proposed simulation approach rationally balances the level of sophistication of the adopted model with the need for accurate results. Although based on a formulation assuming only four state variables for the description of landing gear dynamics, the approach successfully accounts for all the relevant forces that arise during the drop and their influence on landing gear motion. A set of intercommunicating routines was implemented in MATLAB® environment to integrate the dynamic impact equations, starting from user-defined initial conditions and general parameters related to the geometric and structural configuration of the landing gear. The tool was then used to simulate a drop test of a reference landing gear, and the obtained results were successfully validated against available experimental data.

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