CALCULATION OF THE STRESS-STRAIN STATE OF THE NOSE STAND OF AN AIRCRAFT LANDING GEAR WITH A RADIUS TRANSITION BY THICKNESS WHEN BUILDING A LOCAL MODEL

Abstract

Purpose. Study of the stress-strain state and fatigue life of the local zone of the compartment structure, namely, the radial transition between the wall thicknesses from the regular zone to the place of thickening in the connection zone with the reinforcement element. The main task of this work is to estimate the level of stress in the zone of the radial transition using the numerical solution of the problem, for the further assessment of the resource of the structure. Research methods. Construction of a local model and numerical calculations of the stress-strain state of the considered structure using PATRAN/NASTRAN software complexes. Using the Mesh Seed tool to mark the position of nodes on the edges of surfaces. In addition to flat elements, bar elements were used in the model to simulate rivets. For the numerical solution of the presented problem, the nonlinear solver 106 - Nonlinear Static was used. Results. A numerical calculation of the stress-strain state of the nose strut of the aircraft landing gear with a radial transition in thickness during local modeling was carried out. Visualization of linear displacement and fields of normal stresses, as well as graphs of normal stresses on the lower and upper surface of the wall, and the dependence of the values of normal stresses in the radial transition zone were obtained. The deflection of the plate between the reinforcement element is plotted and the maximum deflection in the middle of the span is obtained. Scientific novelty. Application of the method of calculating the stress-strain state of complex structures of aviation equipment elements using computer software complexes in the conditions of modern development of aviation science and technology. Practical value. The obtained calculations made it possible to estimate the resource of the local area of the structure - the radius transition between different wall thicknesses. The results of the analysis and the method of numerical calculation of the stress-strain state of the considered model can be used for further assessment of the resource and static strength of the structure of the aircraft landing gear compartment.