CONCEPTUAL DESIGN AND OPTIMIZATION OF AIRCRAFT LANDING GEAR SYSTEMS BY USING ANSYS SOFTWARE

Abstract

Landing gear is a vital structural unit of an aircraft which enables to take off and land safely on the ground. A variety of landing gear arrangements are used depending on the type and size of an aircraft. Even during a normal landing operation heavy load are to be absorbed by the landing gear. In turn joints are to be provided such that such heavy concentrated loads are first received by the airframe and subsequently diffused to the surrounding areas. Normally heavy concentrated loads are received through a lug joint. Therefore, design of a lug joint against failure under static and fatigue loading conditions assumes importance in the development of an aircraft structure. This project deals with the design and analysis of a typical lug joint representative of a landing gear attachment of a small airplane. The design will provide safety against failure of the lug, and failure of the pin in Catia. A typical landing load case will be assumed for which structural analysis will be carried out. The landing gear space structure will be idealized as a statically determinate structure and a stress analysis will be performed using strength of Material approach. The stresses developed because of all three types of loading on the structural members of the landing gear will be calculated. A finite element model of the landing gear structure will be developed and analyzed in Ansys. The FEA stress and deformation results will be compared. These stresses and internal loads can then be used for the design of various structural members of the landing gear unit. Fatigue life to crack initiation will be estimated for a critical lug of the landing gear unit by considering the constant amplitude landing cycles.