Fatigue life calculation method for stiffened plate structure taking temperature and random vibration load into account

Abstract

The invention discloses a fatigue life calculation method for a stiffened plate structure taking temperature and a random vibration load into account. Pro / E three-dimensional modeling software is adopted to establish a geometric model of a supersonic aircraft stiffened plate; an ANSYS thermal stress analysis module is adopted to calculate a thermal temperature field and thermal stress distributionof the stiffened plate under different surface temperature loads; based on a modal analysis module, the influence law of the temperature load on the first six modes is analyzed; the maximum stress time domain spectrum obtained by ANSYS analysis is imported into matlab software in the form of .txt, and the fatigue damage under set conditions is calculated by combining the Miner linear damage accumulation theory and an S-N curve of the stiffened plate material to obtain service life parameters of the stiffened plate. By establishing geometric model parameters of Proe of the stiffened plate andthermal-vibration coupling parameters of the ANSYS model and integrating frequency domain analysis of matlab and PSD analysis process, the service life of the stiffened plate under certain working conditions, structural parameters and material properties can be optimized.

Description

technical field [0001] The invention relates to a method for calculating the fatigue life of a stiffened plate structure considering temperature and random vibration load, belonging to the field of fatigue life calculation of mechanical parts; Background technique [0002] A hypersonic aircraft is an aircraft that flies at a speed higher than 5 times the speed of sound, that is, Mach 5 (HM), and can reach a destination in a short time over a long distance to perform missions such as attack, transportation, and reconnaissance. The reinforced panel of a hypersonic vehicle belongs to the thermal protection system of the aircraft, and the service environment of the reinforced panel is very complicated. During the cruising process of the aircraft, the structure will bear a large vibration load, which will cause damage to the structure. During the flight of a hypersonic vehicle, the stiffened plate on the surface of the body is coupled by the random vibration load of the engine o...

AI Technical Summary

Problems solved by technology

During the flight of a hypersonic vehicle, the stiffened plate on the surface of the body is coupled by the random vibration load of the engine or external air pressure and the high temperature load on the surface, and its mechanical properties will undergo significant changes. Cause fatigue damage, seriously affecting the service life of hypersonic aircraft

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