Construction of a retractable single-strut undercarriage in fiber composite design for the motorized sailplane “Valentin Taifun 17E”

Tesis , 2016 , 171 Páginas , Calificación: 1,3

Ingeniería - Ingeniería mecánica

The purpose of this thesis is to calculate, interpret and construe a retractable one-wheel landing gear for the motorized sailplane “Valentin Taifun 17E”. Therefore the available space in the sail plane was measured and the data was transferred into the CAD-system “Autodesk Inventor”. The calculative position of the extended landing gear, in dependence of the variable center of mass and in due consideration of the requirements of the JAR 22, was determined. Due to the information about the position of center of mass and of further considerations, the position of the landing gear mounting could be determined so the retraction kinematic of the carriage was automatically stated.

The extension should be realized with lever mechanism and the carriage needs to be locked in extended position. With the aid of a market research and creativity techniques, different construction possibilities were created. These constructions were assessed, so that a winner version could be chosen for further contemplation.

In order to construe the single components of the carriage it was necessary to identify the occurring forces and to design and construe the components in dependence of the characteristic cases of damage. To determine the acting forces it was necessary to take into account the spring constant and the optimal tire pressure of the used tire, which was therefore determined in the course of this diploma thesis.

The construction process was done according to the flow of forces during the landing impact. During the construction many different components were developed. They were compared with each other, so that the best part accomplishes the most with the requirements: lightness, stability and simplicity.

The developed construction needs to be considered as a first prototype and as the basic for further improvements of the carriage, before it is getting finally implemented into the “Valentin Taifun 17E”.

Table of Contents

• 1. INTRODUCTION AND PRESENTATION OF THE TYPE OF PROBLEM
• 1.1 Valentin Taifun 17E
• 1.2 Standard carriage of the Taifun 17E, its problems and task of the thesis.
• 2. FUNDAMENTALS OF THE MANUFACTURE OF SANDWICH-STRUCTURED COMPOSITES.
• 2.1 Fundamentals.
• 2.2 Showcase of manufacture of a sandwich constructed fuselage plate
• 3. BOUNDARY CONDITIONS
• 3.1 Determination of position of the landing gear in the extended position
• 3.1.1 Determination of center of mass under consideration of different load conditions.
• 3.1.2 Determination of the horizontal landing gear position under disregard of plane inclination
• 3.1.3 Comparison with available space
• 3.1.4 Adaption of the landing gear position
• 3.1.5 Provision for the start-kick.
• 3.1.5 Further considerations
• 4. LOAD ASSUMPTION OUT OF THE JOIN AVIATION REQUIREMENTS
• 4.1 Level landing condition
• 4.2 Lateral load conditions
• 4.3 Lever control
• 4.4 Limit maneuvering load factor
• 4.5 Wheel
• 4.6 Factors of Safety.
• 5. CONSTRUCTION POSSIBILITIES.
• 5.1 Version 1 – Description and Evaluation
• 5.2 Version 2 - Description and Evaluation.
• 5.3 Version 3 - Description and Evaluation.
• 6. CONSTRUCTION AND STRESS ANALYSIS VERSION 3
• 6.1 Wheel.
• 6.1.1 Experimental set-up
• 6.1.2 Calibration.
• 6.1.3 Execution
• 6.1.4 Selection of the tire pressure.
• 6.2 Axle
• 6.2.1 Forces on the axle by "normal landing load case".
• 6.2.2 Forces on the axle by "lateral load case".
• 6.2.3 Contact pressure between axle and fit bushing
• 6.3 Bushings
• 6.3.1 Execution of the bushings
• 6.3.2 Bearing Pressure between spherical plain bearing and bushing
• 6.3.3 Bearing pressure between bushing and roving truss.
• 6.3.4 Implementation of the brake
• 6.4 Gear swing
• 6.4.1 Framework
• 6.4.2 Bending truss.
• 6.4.3 Bending truss with shear field
• 6.3.4 Compression strut - behavior during compression.
• 6.5 Framework trusses 1 and 2
• 6.5.1 Framework truss 1
• 6.5.2 Framework truss 2
• 6.5.3 Console wall
• 6.6 Connection of the framework trusses 1 and 2
• 6.7 Connection of framework truss 1 with the wheel and the gear swing
• 6.8 Bolt mechanism
• 6.8.1 Requirements of the single components.
• 6.8.2 Execution and assembly.
• 6.8.3 Improvements.
• 6.9 Lever mechanism - extending and retracting
• 6.9.1 Requirements and execution
• 6.9.2 Actuating force.
• 6.10 Bench face - Holm mounting.
• 6.10.1 Contemplation and determination of loads transferred by axle.
• 6.10.3 Thickness for perpendicular/lateral loads.
• 6.10.4 Adhesive bonded joint
• 6.11 Connection of the holm mounting with the gear swing and framework truss 2
• 6.11.1 Manufacturing and assembling
• 6.11.2 Stress analysis of the "bench face axle".
• 7. EVALUATION AND FURTHER PROCEDURE.

Objectives and Key Themes

This diploma thesis examines the construction of a retractable single-strut undercarriage for the motorized sailplane "Valentin Taifun 17E" using fiber composite design. The aim is to address the shortcomings of the standard undercarriage and develop a lightweight, retractable solution that meets the specific requirements of the aircraft.

• Design and analysis of a retractable undercarriage system.
• Optimization of weight and performance characteristics.
• Material selection and manufacturing techniques for composite structures.
• Integration of the undercarriage into the existing aircraft design.
• Evaluation of the structural integrity and functional performance of the system.

Chapter Summaries

The thesis begins by introducing the "Valentin Taifun 17E" and outlining the limitations of its current undercarriage system. Chapter 2 delves into the fundamentals of manufacturing sandwich-structured composites, providing a foundation for the proposed design. Chapter 3 establishes key boundary conditions, including the determination of the landing gear position and considerations for load distribution. Chapter 4 focuses on load assumptions derived from aviation requirements, examining various loading scenarios. Chapter 5 explores different construction possibilities for the retractable undercarriage, comparing their advantages and disadvantages.

Keywords

Retractable undercarriage, fiber composite, sandwich structures, structural analysis, aircraft design, motorized sailplane, "Valentin Taifun 17E", weight optimization, load distribution, aviation requirements, manufacturing techniques.

• Universidad: Würzburg-Schweinfurt University of Applied Sciences
• Calificación: 1,3
• Autor: Gabriel Ossyra (Autor)
• Año de publicación: 2016
• Páginas: 171
• No. de catálogo: V375476
• ISBN (Ebook): 9783668555327
• ISBN (Libro): 9783668555334
• Idioma: Inglés
• Etiqueta: construction, valentin, taifun