Design of landing gear linkage by using composite material

Published on 28 May 2021. Written by Gurudutt

The landing gear is a structure, which supports the aircraft in the ground. A major part of aircrafts load is transferred to the landing gear during take-off and landing. These loads are then transferred to the airframe through landing gear beams. Wheels of the landing gear are added as per the size of the aircraft. The position of the landing gear depends on the design, type, and load of the aircraft. Some landing gear is mounted on wing and some under the fuselage.

In this project, we are going to create and analyze a 2D and 3D model of lug attachments in the landing gear.

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Objectives:

The main objective is to design a landing gear lug attachment by using composite material. This landing gear unit is designed for 150-seater aircraft. A typical landing load case will be assumed and for that load structural analysis will be carried out.

Project Description:

• Composite Material: Two or more materials combined to give advantages of both the material is known as a composite material. Composite materials are widely used because they can withstand high temperature, high resistance, high tensile strength, and more weight compared to other materials.
• Landing gear types:

1. Tail wheel-type landing gear: In this type of landing gear, the 2 wheels are located forward from the center of gravity, and a third wheel to support the tail.
2. Tandem landing gear: Usually, the tandem landing gear is mounted on the centreline of the aircraft one after the other as in commercial aircraft. Tandem landing gears are retractable type.
3. Tricycle-type landing gear: This type of landing gear has 2 wheels in front and third wheel forward from the center of gravity. The tricycle has benefits of withstanding more loads without skidding.

Methodology:

• Conceptual design: The following are the standard parameters to design the model.

Properties	Symbol	Values
Max Weight	W	69400kg
Wheel Base	B	12.4m
Fuselage Length	L	32.18m
Co-Efficient of friction	µ	0.5
Thrust of Engine(2 Units)	T	120kn×2

 

• 2D Design of Lug Attachments:

                  Formulae used for designing of Lug

1. σ=P/A
2. Height, H = 2 × d
3. Bearing stress calculated as

                       σ=P/d*T

                Final dimensions Diameter, Height, Breadth of lug are obtained by solving the above equations.

• 3D Model of Lug Attachment(3mm): 3mm thickness of bracket is used for modeling of lug attachment.
• Analysis: It is done after completion of 2D, 3D model designing and meshing of both the models.

Conclusion:

Initially, the load is calculated by the strength of the material approach & factor of safety is taken as 1.5times. Based on this, lug dimensions are obtained. The lug joints made up of CFRP material is analyzed using ANSYS. The stress contour is plotted and maximum stress is found below the stress limit thus the design is safe.

Kit required to develop Design of landing gear linkage by using composite material:

• CATIA
• ANSYS

Technologies you will learn by working on Design of landing gear linkage by using composite material:

• Testing apparatus
• Analysis

Any Questions?