Dynamic analyses of the landing gear are conducted to provide capabilities to forecast their behavior under haz ardous conditions. This kind of investigation with numerical methods implementation is much easier and less expensive than stand tests. The major advantage of the presented numerical method is applicability to landing gear tests with artificially introduced flaws.

http://www.wseas.us/e-library/conferences/2008/malta/ecc/ecc20.pdf

Strength analysis of 3D landing gear model with failure

Numeryczne odwzorowanie warunków współpracy elementów podwozia głównego w fazie przyziemienia na dwa koła

Analiza układu podwozia samolotu transportowego w fazie przyziemienia

Modular floating systems are structures used both for the army and the civilian population needs. They enable construction of temporary water crossings, for example, in place of permanent out of service bridges or objects renovated due to mechanical and other damages. Special features of this type structures include the possibility of using them regardless of the depth and terrain conditions of the water crossings. The requirements currently set for such structures force their modernization as well as search for innovative solutions. They should allow easy and quick assembly-disassembly of the structure, and have a low weight and dimensions to facilitate transport as well as minimize storage space. These requirements are met by a pontoon construction based on an innovative cassette designed in Poland (Military University of Technology). A single cassette contains a high-strength elastic coating pontoon which, after filling with air, allows obtaining the regulation of buoyancy force, appropriate depending on the type of water crossings. The paper deals with testing the load capacity of a pontoon bridge composed of repetitive segments-cassettes with adjustable immersion. Numerical models of a single floating cassette and a group of connected cassettes constituting ferries or sections of a pontoon bridge are also presented in the paper. The methodology for load capacity tests and selected test results of such floating objects are discussed. Multibody numerical methods and FEM (Finite Element Method) are used for dynamic and static analysis of multi-component floating systems. Selected field tests and laboratory stand tests conducted with the use of the strength machine are applied to validate the various type of numerical models.

Selected Problems of the Numerical Capacity Assessment for Floating Systems

Properly adjusted characteristics enable minimisation of loads that occur in the landing-gear components at the moment of touchdown. Therefore, dynamic analyses of the landing gear are conducted to provide capabilities to forecast their behaviour under hazardous conditions. This kind of investigation with numerical methods applied is much easier and less expensive than stand tests. However, the development of the landing gear FEM models is necessary. Methodology of the main landing gear numerical models developing and procedures of parameters selection for the real structure features representation is discussed in the paper. The nonlinear physical material properties were precisely defined. To describe material properties of all mechanical components of the landing gear, a materials chart describing parameters for the elastic range was used. In FEM model the following matters were taken into consideration: contact problems between collaborating elements, the phenomena of energy absorption by gas-liquid damper placed in the landing gear and the response of the landing gear during touchdown of a flexible wheel with the ground. Chosen results of the numerical analysis for the maximum load of the gear considered, corresponding to an aircraft’s 3-point landing at maximum decline speed allowed have been compared to experimental research’s results. The analysis presented in this paper is the first part of wider considerations concerning numerical assessment of landing gear life.

http://yadda.icm.edu.pl/yadda/element/bwmeta1.element.baztech-article-BUJ8-0005-0005/c/httpwww_bg_utp_edu_plartjok32007jo20kones20200720no20320vol201420krason.pdf

W. Krasoń

Papers

Dynamics analysis of the main landing gear in 3d model