S B Batdord

Bio: S B Batdord is an academic researcher. The author has contributed to research in topics: Elasticity (economics). The author has an hindex of 1, co-authored 1 publications receiving 5 citations.

Analysis of Landing-Gear Behavior

Abstract: This report presents a theoretical study of the behavior of the conventional type of oleo-pneumatic landing gear during the process of landing impact. The basic analysis is presented in a general form and treats the motions of the landing gear prior to and subsequent to the beginning of shock-strut deflection. The applicability of the analysis to actual landing gears has been investigated for the particular case of a vertical landing gear in the absence of drag loads by comparing calculated results with experimental drop-test data for impacts with and without tire bottoming. The calculated behavior of the landing gear was found to be in good agreement with the drop-test data.

Effect of interaction on landing-gear behavior and dynamic loads in a flexible airplane structure

Abstract: The effects of interaction between a landing gear and a flexible airplane structure on the behavior of the landing gear and the loads in the structure have been studied by treating the equations of motion of the airplane and the landing gear as a coupled system. The landing gear is considered to have nonlinear characteristics typical of conventional gears, namely, velocity-squared damping, polytropic air-compression springing, and exponential tire force-deflection characteristics. For the case where only two modes of the structure are considered, an equivalent three-mass system is derived for representing the airplane and landing-gear combination, which may be used to simulate the effects of structural flexibility in jig drop tests of landing gears. As examples to illustrate the effects of interaction, numerical calculations, based on the structural properties of two large airplanes having considerably different mass and flexibility characteristics, are presented.

A Study of the Response of an Airplane Landing Gear Using the Differential Analyzer

Abstract: The response of a conventional airplane landing gear is studied by deriving and solving the differential equations of motion for the system. The resistance of the air-oil shock strut depends upon an orifice damping coefficient and an exponent, y, which determines the air pressure as a function of volume. A study of experimental "drop-test" results on similar systems is made to determine these constants. The nonlinear equations of motion are solved by means of the differential analyzer for (1) the landing condition as simulated by a drop test and (2) the taxiing condition in which a periodic ground contour function is assumed. The differential analyzer solutions for the landing condition are compared with drop-test results on the same system.

Impact Loading Analysis of Light Sport Aircraft Landing Gear

Abstract: 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.